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UBC Theses and Dissertations

Marine magnetic survey in the Mackenzie Bay/Beaufort Sea area arctic Canada 1972

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A MARINE MAGNETIC SURVEY IN THE MACKENZIE BAY / BEAUFORT SEA AREA ARCTIC CANADA by ROCQUE GOH B.Sc. Honours, University of Salford, England, 1968. A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of GEOPHYSICS We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA April 1972 In presenting this thesis in pa r t i a l fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make i t freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of Geophysics The University of British Columbia Vancouver 8 Canada 5 April 1972 (i) ABSTRACT This thesis presents an investigation of the variations in the magnetic f i e l d obtained in the Mackenzie Bay/Beaufort Sea area of the Canadian Arctic. It was found that the variations obtained at sea were strikingly correlated with those recorded at Point Atkinson, a fixed station on land, 150 miles from the survey area. In addition, i t was found that the higher frequencies present in the marine records were severely attenuated with respect to the corresponding frequencies in the Point Atkinson recordings. It was concluded that the Mackenzie Bay/Beaufort Sea area is geomagnetically anomalous and that this situation is probably caused by higher e l e c t r i c a l conductivity material underlying ,the Mackenzie Bay/Beaufort Sea area, abutting lower conductivity material of the North American craton underlying Point Atkinson. This conclusion has important implications relating to the tectonic history of the Canadian Arctic. ( i i ) TABLE OF CONTENTS ABSTRACT (i) LIST OF FIGURES ( i i i ) LIST OF MAPS (iv) LIST OF FLOW CHARTS (v) ACKNOWLEDGMENTS (vi) INTRODUCTION 1 CHAPTER 1 DATA COLLECTION 4 CHAPTER 2 DATA REDUCTION 9 CHAPTER 3 DATA CORRECTION AND MARINE MAGNETIC MAPS 18 CHAPTER 4 AN ANOMALY IN GEOMAGNETIC VARIATIONS 33 CONCLUSIONS 55 BIBLIOGRAPHY 57 APPENDIX I DECCA NAVIGATION SYSTEM CHARACTERISTICS 61 APPENDIX II TABLE OF COMPUTER PROGRAMS & NOTES ON PROGRAMS 63 APPENDIX III SOURCE LISTINGS OF COMPUTER PROGRAMS 73 ( i i i ) LIST OF FIGURES FIGURE 1 A Simple Model of Geomagnetic Induction FIGURE 2 Comparison between Shipboard Magnetic Variations and Station Magnetic Variations FIGURE 3 Detailed P r o f i l e s Comparing Marine and Station Magnetic Variations FIGURE 4, Detailed P r o f i l e s Comparing Marine and . Station Magnetic Variations FIGURE 5', Power Spectra for Mackenzie Bay data. FIGURE 6 Power Ratio between Mackenzie Bay Marine data and Point Atkinson Station data FIGURE 7: . . -Graphs showing Attenuation at Higher Frequencies f o r Geomagnetic Variations recorded at Mould Bay & Castel Bay compared with Sachs Harbour FIGURE 8, Navigation Program 'DECNAV1 - Test of Interpolation Routines used i n program 43 44 45 48 49 54 72 (iv) LIST OF MAPS MAP 1 Ship's Track Plot 24 MAP 2 Anomalous Field - Marine Magnetics 25 Map MAP 3 Residual Station Magnetics Map 26 MAP ,4 . RMS F i t Map 27 MAP 5 . Location Map 38 MAP 6. Map showing geographical 52 relationship between geomagnetic situations and tectonics (v) LIST OF FLOW CHARTS FLOW.. CHART 1 Overall Data Reduction Flow Chart 10 FLOW CHART 2 Program 'PTAPE DECODER* Flow Chart 69 FLOW CHART 3 Program 'DECNAV' Flow Chart 70 FLOW CHART 4 . Program 'MAGNAVM' Flow Chart 71 (vi) ACKNOWLEDGMENTS I would like to thank Dr. Tad Ulrych, f i r s t of a l l , for his encouragement and unflinching support as thesis advisor throughout this work. Dr. Laurie Law and Dr. Ron Niblett unselfishly gave many ideas on geomagnetic anomalies during discussions with them—much of this thesis must be credited to them. Dr. Roy Hyndman established many basic plate-tectonics and g.v.a. concepts in my mind. In addition, his criticism of this work has resulted in a much more comprehensive thesis than would have been possible. I am also very grateful to many at the Atlantic Oceanographic Laboratory of the Bedford Institute, pa r t i - cularly Ron Macnab, Brian Maclntyre and Dr. S. P. Srivastava. Ron Macnab held a superb informal-school at sea and started the magnetic data collection off on the right foot; Brian Maclntyre has fielded the many requests for assistance with this project—undoubtedly he has spent much time and patience doing this; Dr. Srivastava gener- ously gave access to and commented on data from the CSS HUDSON and CSS BAFFIN in their work in the Arctic the same year. With respect to data collection, this thesis would not have been possible without support from a l l members of the cruise on the CSS PARIZEAU—particularly the Master, Captain Colin Angus and the Chief Hydrographer, Stan Huggett. In addition, I would also like to thank Dr. Don T i f f i n of the west-coast Marine Sciences group, (vii) Geological Survey of Canada in Vancouver for his generous support of this project. Brian Clarke of the Marine Sciences Branch, Department of the Environment (formerly the Canadian Hydrographic Service) must be mentioned for his prowess in computer-program bug-finding. Much time was spent on the computer-processing of the large amount of data gathered in this survey. I have obtained meaning- ful results only with the help of the superb staff at the Computing Centre here at the University of British Columbia Numerous others have given heartfelt encouragement and made studies at this university a great pleasure,. To each and every one, I am very grateful. - 1 - INTRODUCTION The. purpose of this thesis was to carry out, integrate and interpret a marine magnetic survey in the Mackenzie Bay/ Beaufort Sea area in the Canadian Arctic. The survey was conduc- ted, on. board the Canadian government oceanographic ship, CSS PARIZEAU,, in the summer of 1970. The f i r s t chapter, deals with data collection and contains details, of the equipment used as well as general stat i s t i c s regarding the .survey. Chapter 2 i s concerned with data reduction and includes discussion of the method of reduction, processing and of the computation techniques involved. The actual computer programs which were written and used for the data reduction are detailed in Appendix II. The source listings are given in Appendix III. Data correction is dealt with in Chapter 3. It was found that the. marine magnetic data reflected the magnetic noise and diurnal variations which were monitored at a fixed shore station at Point Atkinson, approximately 150 miles east of the survey area. However, though remarkably well cor- related, the magnetic noise recorded at sea was found to be severely attenuated compared to the noise recorded at Point Atkinson. Further, the attentuation was found to be highly frequency dependent. This observation suggested that a geo- magnetic variation anomaly exists in the intervening area - 2 - between the Mackenzie Bay area and Point Atkinson—this anomaly was investigated further and is discussed in Chapter 4. Due to the geomagnetically anomalous conditions, reliable corrections .for magnetic noise cannot be made to the Mackenzie Bay. marine .magnetic data which are therefore presented as uncorrected maps. The geomagnetic, .variation anomaly found, named the Mackenzie Bay geomagnetic variation (g.v.a.) is investigated and.discussed in Chapter 4. The frequency attenuation charac- teristics of the anomaly parallel those of another anomaly known.to exist.at Mould Bay on Prince Patrick Island approximately '•; '600 miles towards the north-east(Whitham, 1963). A third . anomaly at Alert on Ellesmere Island(Whitham et a l , 1960), ; approximately another 700 miles north-east from Mould Bay, brings to three the number of anomalies now known in the Canadian Arctic. Geomagnetic variation anomalies appear to occur preferentially in the zone affected by a tectonic plate boundary. Study of those anomalies known throughout the world , that ;are not explainable by the coast effect support this ;concept.(Law and Riddihough, 1971). This is because tectonic and geological situations that would give rise to geomagneti- cally anomalous conditions occur in the tectonically active zones at plate boundaries. The Mackenzie Bay anomaly is no - 3 - exception—it occurs in the region suggested to be the edge of the, stable North American cr.aton(Geol. Surv. of Canada, 1969; King,..1969). . It is apparent from this survey that noise corrections for -marine magnetic, surveys .within a geomagnetically anomalous zone,, particularly in the high latitudes present extremely serious.problems. This is especially true i f the shore monitor station, is far removed from the survey area. The problems encountered „in, the present survey probably also apply to the magnetic data collected by the CSS BAFFIN and the CSS HUDSON during the same period especially since both ships surveyed areas ..suspected to be over the central region of the Mackenzie Bay geomagnetic variation anomaly. ..... Further investigation of the Mackenzie Bay geomagnetic variation anomaly is required before more quantitative results can be obtained. Of particular interest would be to determine the extent of this anomaly. There would be strong plate tectonic implications i f i t is found to extend and connect up with the Mould Bay anomaly to the north-east. CHAPTER 1 DATA COLLECTION INTRODUCTION The marine magnetic data was collected from the CSS PARIZEAU. by. the usual method' of towing a t o t a l - f i e l d pre- cession magnetometer sensor astern. A magnetic reading was obtained every, six. seconds and the readings were recorded, along with the G.M.T. time every minute, on a paper-tape punch. .In addition, the positions .of the ship at various times were logged... Interfacing of the paper-tape data and the ship's positions produced the required result of the ship's position with a marine .magnetic reading and time attached. In a l l , 44 days were spent in the survey area, resulting in approximately 3 600 nautical miles of magnetic data. Subsequent editing, integrating and processing yielded 134 000 magnetic, readings on which this thesis is based. In general, the accuracy of the survey is regarded as good. The magnetometer is capable of ±1 gamma precision while the navigation is regarded as being accurate to ±110 meters. THE MARINE MAGNETOMETER The instrument used to measure the Total Magnetic Field at sea was a Barringer Oceanographic Magnetometer, Type OM-104. This is a precession-type magnetometer, accurate to ±1 gamma (Barringer, 1970). It was towed approximately 600 feet astern of the ship at depths in the order of 50 feet below the surface of the sea. DATA LOGGING Two sets of data were logged for the survey. The f i r s t set consisted of the Total Field readings obtained from the marine magnetometer—these readings and the G.M.T. times at which they were taken were recorded on punched paper-tape, encoded in. Eriden-code. TheG.M.T. times were derived from an electronic,clock on board. The second set of data consisted of the ship's positions and the G.M.T. times at which i t occupied these positions. Combining the two sets of data produced the magnetic readings, the positions at which these were taken and the corresponding times. Computations of the positions and the combinations of the two sets of data are covered in Chapter 2. - 6 - THE NAVIGATION SYSTEMS Two navigation systems were used for this survey—a DECCA 6 F system and a DECCA Minifix system (registered trade names owned by the Decca Navigator Company). Both systems u t i l i s e the same principles of operation—electromagnetic waves are radiated from three shore stations, these waves forming, standing wave patterns. Between the three stations, two such patterns, are set, .up—so that in plan view, one would see essentially two sets of waves, similar to the two sets of waves.that would be generated i f three stones were simultaneously thrown into.a pond, a short distance apart. Note that two sets of waves are required for a position to be obtained since two lines of intersection (i.e. two co-ordinates) are needed to define a position in any two-dimensional co-ordinate system. For the 6F and Minifix Decca systems used, the patterns of the waves are not circular as are ripples in a pond— they are hyperbolic as shown in Figure 8 , because they are interference .patterns. Decca waves for the 6F and Minifix systems used,, are waves of constant phase difference between the two sets of circular waves radiated by two stations. These waves are hyperbolae since for any hyperbolae, the differences between the. distances from points along the hyperbolae to the two foci,are constant. The constant distance difference is expressed as a phase difference for the Decca system—so that - 7 - the hyperbolic waves are waves of constant distance differences which means they are waves of constant phase differences. It is usual to use another term for Decca waves— lanes, akin to lanes of t r a f f i c . A l l positions obtained through the use of a Decca system (such as the 6F and Minifix system) are therefore obtained in terms of Decca lanes, akin to obtaining one's position at a city intersection by noting the streets., forming, the: intersection—except Decca lanes intersect one another at different angles since they are hyperbolae themselves. It should..be remembered that implicit in the word 'lane' is the fact that a l l lanes are hyperbolic in plan view. In using Decca navigation systems,, three kinds of errors can be. expected. The f i r s t is a Repeatability E r r o r — a measure of how accurately one may repeatedly position oneself within a given system. This error is larger for positions further away from the shore stations since, the further out to sea, the more obscure the intersections between lanes become. Repeatability of the Decca 6F system in the survey area is approximately ±100 meters—that of the Minifix system is smaller ( C H S , 19 70). The second kind of error is one caused in part by pattern variations. Patterns may shift as a result of the warming of the atmosphere with daylight. To determine pattern shifts, pattern readings were monitored at a fixed station - 8 - over the period of the survey. It was found that pattern shifts were less than ±0.06 lane for the period of the marine magnetic survey (CHS, 19 70). The third, kind of error is related to the magnetic survey alone. The ship's position was recorded only for the start and end .of each line run—no positions were recorded in between and i t was assumed that the ship maintained constant speed for the duration of the line. Since the lines run were relatively, short—2 hours sailing time or 32 nautical miles approximately—the error in this assumption i s not too serious. .The ship's path of travel in between the start and end of the line was,either a straight line or a hyperbola. The straight line case occurs when the ship's course is direct—while the hyperbolic case occurs when the course i s along some Decca lane, staying to within ±0.05 of a lane, this accuracy being ascertained from .the ship's logs. Combining the estimates of the three kinds of errors involved, the r„m.s. error that can be expected in the position of the ship is approximately ±110 meters. Errors measured in lanes were converted to errors in metres by using the fact that the baseline lane width, i.e. the maximum lane width, for the Decca 6F system is 561 metres. The system characteristics for both Decca 6F and Decca Minifix systems is given in Appendix I. - 9 - CHAPTER 2 DATA REDUCTION INTRODUCTION Most of the programs required for the computer-processing of the data were written as part of this thesis. A l i s t of the programs is given in Appendix II. The overall sequence of data processing is shown in Flow Chart 1. The papertapes which contain, encoded in Friden, a time parameter and the total f i e l d reading taken at that time, were transcribed onto magnetic tape. This tape was then decoded using the program 'PTAPE DECODER'. The navigation data, recorded by hand separately, consisted of a time para- meter and the Decca co-ordinates of the ship at various times. Program 'DECNAV' converted these Decca co-ordinates into more recognisable geographic and UTM co-ordinates, with proper interpolations in time suitable for the next stage of processing. Having time/total f i e l d on the one hand, and time/co-ordinates on the other, the next stage of processing was to match the two on a basis of time. This was done by the matching program 'MAGNAVM'. In addition to matching, 'MAGNAVM' also computed the regional f i e l d and the anomalous f i e l d readings for each set of co-ordinates produced by 'DECNAV'. The output of 'DECNAV', being a series of scattered data points, was then prepared for p l o t t i n g — t h i s necessitated gridding the data onto FLOW CHART 1 OVERALL. DATA REDUCTION FLOW CHART MARINE M A G Q C L O C K • M A R I N E MAG < T IME N A V L O G • POSIT ION •» T IME S T A T I O N M A G a C L O C K • S T A T I O N M A G « T I M E M A T C H MARINE MAG TO NAVIGATION M A T C H STATION MAG TO NAVIGAT ION C O R R E C T FOR R E G I O N A L C O R R E C T FOR A V E R A G E V A L U E AT S T A T I O N RESIDUAL STATION MAG ( M A P • 3 I R M S FIT P R O G O N E 0IMENSIONAL P L O T PROG T I M E - S E R I E S P L O T S ( F I G S , s a i l POWER SPECTRA COMPUTATIONS POWER SPECTRA P L O T S I F I G S . 3 8 6 1 - 11 - a rectangular g r i d acceptable to plotting/contouring programs av a i l a b l e at the University of B r i t i s h Columbia. The gridding and p l o t t i n g were done by 'GRID' and 'PLOTTER' resp e c t i v e l y . In.addition to the t o t a l f i e l d readings obtained from the ship-towed,magnetometer,.a. Station Magnetometer was set up. at Point Atkinson, approximately 150 n a u t i c a l miles from the survey area. This magnetometer (a Barringer precession magneto- meter, s i m i l a r . t o .the one used at sea—accuracy ±1 gamma) monitored the t o t a l magnetic f i e l d at the s i n g l e l o c a t i o n so that any f l u c t u a t i o n s i n this f i e l d would represent the 'magnetic noise' present at the t i m e — t h i s magnetic noise would include any time v a r i a t i o n s i n the Earth's magnetic f i e l d . NAVIGATION INTERPOLATION SCHEME Spec i a l mention has to be made of the scheme of i n t e r - p o l a t i o n used i n the navigation program 'DECNAV1. During the survey, only the s t a r t positions/times and end positions/times were recorded f o r each l i n e traversed. I t i s known from ship !s logs, that i n between the s t a r t and end, the ship kept to within a pre-selected path within c e r t a i n l i m i t s of error. This pre-selected path was e i t h e r a s t r a i g h t l i n e or a hyperbolic Decca lane. Interpolations for the s t r a i g h t l i n e path are simple enough—since, knowing the s t a r t s and ends of the l i n e , we can - 12 - interpolate linearly. For the hyperbolic case, however, a heuristic approach was developed and used. Knowing the Decca lane travelled on by the ship, any number of reference lane-positions can be computed. The ship would have travelled over these lane-positions within the limits of steering error. The next step i s to determine the. total distance covered by the line traversed and this is done by adding up the distances between successive lane-positions. From,the.start and end times, the time taken to cover this distance can be found—'dividing the distance by the time would give the average speed of the ship for that line. Since positions are required on a time-interval basis e.g. every two minutes, the interpolations have to be carried out in time-fashion. Using the ship\s speed and the time taken to traverse the line, the distance intervals corresponding to any chosen time-interval can be computed since these distance intervals correspond to intervals along a hyperbolic line. The lane-positions previously computed are used. The distances between successive lane- positions are known. Hence, interpolations can be carried out. between successive lane-positions on a distance-interval basis. As .a test, the navigation program performing these interpolations was fed the start and end parameters for a line of known location. The line was selected for i t s high degree of hyperbolicity (i.e. i t was highly curved) which should produce - 13 - maximum errors in the interpolation scheme used. The most hyperbolic lines for systems such as the Decca 6F and the Decca Minifix are to be found in the areas closest to the shore stations as shown in Map 5. For the actual survey, none of the lines traversed were as hyperbolic as the test line shown in the map. Using the test line parameters, both hyperbolic and linear interpolation schemes used in 'DECNAV' were tested and the Figure 7 shows the results. It is seen that the positions computed for the highly-hyperbolic test line f i t the test line location very closely(to within ±100 m. at least) and i t appears that the heuristic approach taken here i s valid. THE MATCHING PROGRAM 'MAGNAVM' Special mention has also to be made with regard to the matching program 'MAGNAVM'. For data such as these being pro- cessed, i t is seldom possible to record continuously— discontinuities in data are inevitable e.g. due to equipment malfunction. In-attempting to match two sets of data such as the navigation and the magnetics, discontinuities in the data have to be accounted for. To this end, 'MAGNAVM' is capable of matching two sets of data with discontinuities in either set. This a b i l i t y proved useful since MAGNAVM was able to match the navigation data to not only the marine magnetic data but also to the station magnetometer data which were recorded at entirely different time-intervals. - 14 - GENERATION OF THE MAPS In this f i n a l section on Data Reduction, the generation of the maps is discussed. Four maps are presented later on in this thesis—these are: (i) .. The Track Plot--a plot of the ship's positions - for the: whole survey, ( i i ) The -Anomalous Field—Marine Magnetics Map, ( i i i ) The Residual Station Magnetics Map, (iv) The RMS. F i t Map. (i) The.Track Plot - to generate this, the track-plotting program, 'TRACKER' was used. 'TRACKER' reads in the ship's positions for the whole cruise and plots a l l or a fraction of these positions. For this survey, the ship's positions for the whole cruise were available at two minute time intervals (two minutes are equivalent to..approximately 3 200 feet in distance) — of these positions, every f i f t h was plotted so that the Track Plot, Map 1, is a plot of the ship's position every tenth minute or approximately 16 000 feet. The number of positions shown in this map is roughly 1 300. ( i i ) The Anomalous Field*—Marine Magnetics Map—for this map data points at two minute time intervals were used, approximately 6 700 in a l l . These data points were gridded onto a square grid and then contoured. - 15 - ( i i i ) The Residual' Station Magnetics Map - The Station Magneto- meter data (at 5 minute time-intervals) were matched to the navigation data ( at 2 minute time-intervals). This resulted in a data point every 10 minutes or roughly 1 300 for the survey. These data points were gridded onto a square grid and then contoured. For both the Anomalous Field—Marine Magnetics Map and the Residual Station Magnetics Map, a l l the data points had .to be gridded prior to contouring. The contouring programs available at the University of British Columbia at the present, are able to contour only data on a rectangular or square .grid—they are unable to contour scattered data. This just means that the data points to be contoured have to be regularly spaced such that adjacent data points are the same distance apart on a rectangular grid. To 'load' a l l the data points onto a. grid requires a large number of computations— because the value at each point on the grid is affected by the values of any of the scattered data points close to i t . In other words, when many scattered data points are close to a grid point, the value that is assigned to this grid point must take into account each of the scattered data points, taking into account the proximity of the point as well. Obviously the closer a scattered data point is to a grid point, the more weight must be attached to the value of the scattered data point when attempting to assign a value to the grid point. The whole process of gridding scattered data points onto a square grid is done by weighting—each grid point acquires a value which is the mean of a l l scattered data point values close, to i t , with these scattered data point values weighted in some fashion as to reflect their proximity to the grid point., Various techniques of computing the weights have been .used—fbut the .one available at the University of British Columbia adopts, a. heuristic appraoch. For each grid point, the area surrounding i t .is divided into octants. The closest scattered 2 data point within each octant is weighted by a factor of (1/d ) where d is the distance between the particular scattered data point and the grid point, and the mean of the weighted points in a l l ' octants is calculated and assigned to the grid point in question. Should more than four adjacent octants be empty of data points, the grid point in question is assigned a large negative number which causes the contouring program to bypass i t . With the large number of data points obtained for this survey, and realising the large amount of computer-time involved in gridding these onto even the smallest grids, i t was decided to .load a l l the data points for the survey onto a 50 x 50 grid. This causes aliasing of data but aliasing is not regarded as serious for two reasons. F i r s t l y , the magnetic variation spectrum f a l l s off rapidly with increased frequency as Chapter 4 shows. Secondly, the amount by which aliasing w i l l affect the - 17 - data is not significant when compared with corrections for magnetic noise monitored during the survey, which cannot .be made (see Chapter 3 ) . (iv). The RMS .Fit Map- this map was obtained by a pseudo- 'RMS-fit' technique. The RMS values of two input maps, one the signal map. and the other the noise map, are f i r s t computed—the noise map is then multiplied by a factor equal to the ratio of the RMS values of the two maps, such that the noise map has the same RMS value.as the signal map. The modified noise map is then subtracted from the signal map. Interpretation of a l l maps mentioned here is covered in Chapter 3. - 18 - • CHAPTER 3 DATA CORRECTION In the two previous chapters, aspects of data c o l l e c t i o n and data reduction were c o v e r e d — i n this chapter, the problem of data correction i s discussed. For this survey, the data corrections are of two t y p e s — the f i r s t being correction f o r Regional F i e l d , and the second being correction f o r magnetic noise. The term .'magnetic noise' i s used i n a c o l l e c t i v e sense and includes both the time v a r i a t i o n s and the magnetic 'noise' usually most obvious during magnetic storms. REGIONAL FIELD CORRECTIONS For areas such as the Mackenzie Bay/Beaufort Sea area, where the regional magnetic f i e l d i s not well-known, one can, at best, predict on a t h e o r e t i c a l b a s i s , what the regional f i e l d should be. The predicted t h e o r e t i c a l f i e l d , c a l l e d the IGRF(International Geomagnetic Reference F i e l d ) , i s based upon t h e o r e t i c a l considerations of how best to model the magnetic f i e l d of the Earth. Out of these considerations, a mathematical expression i s evolved (Cain, 1965) from which the regional f i e l d may be computed f or a given geographic l o c a t i o n . However, there are complications—the mathematical expression, commonly c a l l e d the PGRF (Polynomial for the Geomagnetic Reference Field) cannot simulate the complicated magnetic f i e l d of the Earth for a l l regions at a l l times. To do this accurately, spatial variations are allowed for in the PGRF in the form of coefficients,-called the PGRF coefficients. Different sets of coefficients apply to different areas and therefore a consistent level of accuracy in the prediction of the Earth's magnetic f i e l d in a l l areas is maintained. Calculations of suit- able coefficients entails tortuous mathematical computations and for this survey, the PGRF coefficients were, thankfully supplied by Ron Macnab of the Atlantic Oceanographic Labora-^ tpry of the Bedford Institute. With these PGRF coefficients in hand, correction for the regional f i e l d was made by computing i t for every geo- graphic location in the survey. The anomalous f i e l d i s then computed as the difference between the total f i e l d and the regional. MAGNETIC NOISE CORRECTIONS As previously mentioned, the term 'magnetic noise' i s used here in. the collective, sense to Include both the diurnal variations in the Earth's magnetic f i e l d , and the magnetic 'noise' commonly prevalent during magnetic storms. For our ,p.urp.osea, •..both: these are. extraneous and not geological effects and must therefore be removed. .. •: For most magnetic surveys, the magnetic noise present is established by monitoring i t at some locale close to or within the survey area for the duration of the survey. This is - 20 - done by setting up a magnetometer at some fixed l o c a t i o n — such a magnetometer is commonly called a Station Magnetometer. Being at a fixed point, the station magnetometer necessarily measures only the ambient f i e l d at that point plus any time variations in the Earth's magnetic f i e l d there, these variations being both the diurnal type and the 'storm' type. By removing the ambient f i e l d , the time variations at the station magnetometer may be extracted and represent a record of the magnetic noise present in the area during the survey. In general, magnetic noise sources are located high up in the ionosphere so that the noise present at a station magnetometer is also present in the general survey area i f i t is close by. The practice in correcting for magnetic noise is therefore.to subtract the time variations of the magnetic f i e l d at a station magnetometer from the magnetic readings recorded at simultaneous times over the survey area. ,; ..For this survey, the station magnetometer was set up at. Point. \ Atkins on approximately 150 nautical miles eastward from.the survey area. The station magnetometer readings were digitised at ,5 minute intervals to give a record of the magnetic noise during the whole survey. In addition to supporting this survey ..in. this manner, the station magnetometer at Point Atkinson also supported magnetic surveys run concurrently by the CSS BAFFIN and the CSS HUDSON in contiguous areas along the Arctic coast nearby. - 21 - Figure 2 shows several days of station magnetometer readings compared to several days' marine magnetic surveying in the Mackenzie Bay/Beaufort Sea area. This "figure shows three features. The f i r s t feature is that the readings at both the survey area and at the station magnetometer are highly correlated. This implies that the readings taken at sea in the survey are heavily doped with magnetic noise. The second feature is that the amplitudes of the magnetic noise signal measured at the station magnetometer are generally much larger than the similar signal recorded at sea. This is particularly true for noise of higher frequencies as Figure 2 shows. We therefore appear to have some suppression of higher frequency s i g n a l s — a major problem in the correction of the data for magnetic noise. The third feature of Figure 2 i s the apparent phase displacement between magnetic noise recorded at the station magnetometer and that recorded at sea. It .appears that this phase displacement is variable in sign—on some occasions the station magnetometer signal leads the signal recorded at sea, on other occasions the reverse is true. This v a r i a b i l i t y in phase displacements between station magnetometer signal and that recorded at sea further complicates the correction of the sea-data for magnetic noise. The reasons are as follows. - 22 - In the f i r s t instance, the commonly used method of correction - subtraction of station magnetometer variations from the survey data - is certainly not useable for this survey. For example,, in Figure 2, at approximately Day 249; the large variations of roughly 400 gammas displayed by the station magnetometer-, when'.subtracted from the smaller variations of roughly 150 gammas recorded at sea, would result in an apparent anomalous f i e l d of -250 gammas which is clearly due to the magnetic noise — the station magnetometer profile points this out. In.the second instance; because the amount of suppression of the magnetic- f i e l d appears to be dependent on the frequency of .the ..magnetic variations, and because the phase displacement between station-recorded noise and sea-recorded noise seems to be variable, • i t would not be meaningful to broadly assume that the suppression is constant over the survey area, and compute a suppression factor. Magnetic noise corrections for this survey therefore appear not to be meaningful - the marine magnetics maps prepared are in fact, an attenuated reflection of the magnetic noise. It is in this-context that one must views the maps which are presented in the next section. MARINE MAGNETICS MAPS As mentioned i n the previous section, correction f or magnetic noise (diurnals and storm vari a t i o n s ) appear to be impossible for this survey. Bearing this i n mind, the following maps are presented: Map 1 „.. The Ship's Track P l o t Map 2 ... The Anomalous F i e l d - Marine Magnetics Map Map 3 ... The Residual Station Magnetics Map Map 4 ... The RMS F i t Map MAP 1 SKIP''5 TRACK PLOT This shows positions occupied by the ship at every tenth minute of time. In r e l a t i o n to t h i s , the other maps presented here can be examined. Map 2 , The Anomalous F i e l d - Marine Magnetics Map, was generated from data points at 2-minute i n t e r v a l s . This means that the number of positions of the ship displayed i n the Track Plot (Map 1 ) i s approximately o n e - f i f t h the number used to generate the Anomalous F i e l d - Marine Magnetics Map. Map 3 , The Residual Station Magnetics Map, was generated from data points at 10-minute time i n t e r v a l s . Since t h i s time i n t e r v a l i s the same as that of the Track P l o t , the positions shown on the Track Plot are approximately those used to generate the Residual Station Magnetics Map. • »0* JO" • U T W C A S T I N G I 7 O N E t »> H T M C A S T I N G   - 28 - As a matter of interest, i t can be seen on the Track Plot that many of the skip's tracks are hyperbolic in shape, the result of sailing 'down a Decca lane'. MAP. 2 - ANOMALOUS FIELD - MARINE MAGNETICS MAP . ( As mentioned previously, this i s a map of the Anomalous Field calculated by subtracting the theoretical regional(IGRF) f i e l d from the Total Field measured at sea. • Two features are apparent. The f i r s t feature is the large 'anomaly' at the south end of the map. It's peak amplitude is of the order of 200 to 25.0. gammas... However, i t is fe l t that this 'anomaly' i s due almost totally to magnetic noise - this w i l l be shown in the discussion of the next map. The second feature is that the 'anomalies' shown on this map appear to be linear i.e. stretched out, along the ship's track. This is true of the large 'anomaly' at the south end of the map and of several 100-gamma 'anomalies' at the north end of the map. These lineations can be seen by inspecting this map, Map 2, and the Track Plot, Map 1, simultaneously. These features are again attributed, to magnetic noise. If magnetic noise is strong, the marine magnetometer towed by the ship w i l l record the noise. If the: noise is. of relatively high frequency, of the order of 60 minutes say, then in the 60 minutes the noise takes to cycle from one amplitude extreme to the other, the ship travelling at about - 2 9 - 16 knots w i l l have travelled roughly 16 nautical miles. The marine magnetometer w i l l then appear to have recorded an 'anomaly' 16 nautical miles long. Should the ship continue to travel and the noise continue to cycle, then the marine magnetometer would record a series of 'anomalies', each 16 nautical miles long. On a map, such 'anomalies' would appear as a series of closures* with perhaps a mean value contour (roughly the zero-gamma contour for an Anomalous Field Map) following 'alongside* a l l these l i t t l e closures—so the net result would probably be a map showing linear- shaped features with pockets of closed contours dotting the crests of these features. Finally, i f as we suspect, the 'anomalies' shown on this Anomalous Field - Marine Magnetics Map are almost entirely due to magnetic noise, and, as we shall see in the next discussion, they are almost a l l accounted for in this way, then i t may be surmised that the survey area must have l i t t l e magnetic character of i t s own, at least in relation to the smaller 100-gamma 'anomalies' due to the magnetic noise. If the area has strong magnetic character of the order of 100 gammas or so, then these would alter the map in. such a way that, i t would, be unlikely that a large number of the 'anomalies.' shown on the Anomalous Field - Marine Magnetics Map could be attributed to magnetic noise. That the area has l i t t l e magnetic character is not a surprising inference since i t is known, from exploratory wells d r i l l e d onshore, that sediment thicknesses - 30 - are of the order of 13 000 feet. The f i r s t exploratory well in the area, B.A. Shell 10E Reindeer D-27, bottomed in sediments at 12 668 feet (Chamney, 1970). MAP 3 - RESIDUAL STATION MAGNETICS MAP This map was generated by taking the magnetic noise recorded by the station magnetometer at Point Atkinson and matching i t on a time basis to the ship's locations throughout the survey. If there had been no magnetic noise present during the survey, this map would show no r e l i e f at a l l . However, as in the case of the previous map, the Anomalous Field - Marine Magnetics Map, two features are apparent. The f i r s t feature, the large 'anomaly' at the south end of the map, is also present on this map (Map 3) except the peak value of the 'anomaly' is of the order of 400 gammas instead of roughly 200 gammas. The second feature, that of lineation of the 'anomalies' along the ship's tracks, is also seen in this map. The most interesting result in comparing the two maps - the f i r s t map which was hoped to be mainly signal and the second map ; which is the noise map - is that the two are highly correlated. Almost a l l 'anomalies' shown on the f i r s t map (the Anomalous Field -Marine Magnetics Map) are mirrored by similar 'anomalies' -.. . on" the second map (the Residual Station Magnetics Map). We - 31 - therefore conclude that almost a l l 'anomalies' recorded at sea are caused by magnetic noise. But in addition to this, the two maps highlight the i n i t i a l conclusions regarding the suppression of the magnetic variations in the survey area (see f i r s t part of this chapter for the' discussion). For example, the large 'anomalies' at the south ends of the two maps, though highly correlated, are very different in amplitude - the one recorded at sea is only half as strong as the one recorded at the station magnetometer at Point Atkinson. On the other hand, the 100-gamma 'anomalies' at the north ends of the two maps appear to have similar amplitudes in both maps— thus, in this instance, l i t t l e or no suppression is present. This strong suppression of the magnetic variations is particularly interesting and leads to the conclusion that we are in fact observing a geomagnetic variation anomaly in a rather unortho- dox manner. A discussion of this phenomenon w i l l be presented in Chapter 4. MAP 4 - THE RMS FIT MAP By f i t t i n g the r.m.s. value of the Residual Station Magnetics Map to that of the Anomalous Field - Marine Magnetics Map, a sort of r.m.s. f i t between the two maps was performed (see end of Chapter 2 for details) and the result i s shown in Map 4. This map shows two features. - 3 2 - The f i r s t feature is that the large 'anomaly' in the south end of the two maps fitt e d together, is s t i l l present. This indicates the r.m.s. f i t technique has failed to remove i t , a result that is not surprising since i t was found that the ratio of the r.m.s. values of the two maps fitt e d together was roughly 0.9--looking at the two fi t t e d maps (Maps 2 and 3), we can see. that a r.m.s. ratio of roughly 0.5 would be required for the large 'anomaly', to be removed by the r.m.s. f i t technique has successfully removed most of the smaller amplitude magnetic noise and in turn re-emphasizes the high degree of correlation between the Anomalous Field - Marine Magnetics Map and the Residual Station Magnetics Map. - 33 - CHAPTER 4 AN ANOMALY IN GEOMAGNETIC VARIATIONS In the previous chapters i t was shown that analysis of the marine magnetic data collected in this survey was complicated because magnetic noise corrections were impossible to apply. This was due to the fact that magnetic noise variations recorded at sea in, the survey area were found to be suppressed in amplitude at the higher frequencies, when compared to variations recorded at the station magnetometer located on shore at Point Atkinson. The suppression of the higher frequency magnetic variations indicated that a geomagnetic variation anomaly(g.v.a.) was present. This chapter deals with the investigation of the nature of this anomaly. A brief introduction to g.v.a.'s is f i r s t given. The evidence for a g.v.a. in the Mackenzie Bay area is presented in the latter part of the chapter. - 34 - AN INTRODUCTION TO GEOMAGNETIC VARIATION ANOMALIES A geomagnetic variation anomaly, as the name implies, is an anomaly in geomagnetic variations. It i s , as Schmucker(1970) pointed out, essentially a difference between the geomagnetic variations recorded at two stations that constitutes an anomalous condition. To understand what g.v.a.'s are, consider the following model, shown in Figure 1. Consider a magnetic disturbance (source field) due to, say, an ionospheric line current, 1^. These are called the primary magnetic disturbance and the primary current respectively, for reasons which w i l l be clear later. FIGURE 1 A SIMPLE MODEL OF GEOMAGNETIC INDUCTION When the primary disturbance impinges upon some point, P, on the Earth's surface, as i s seen i n Figure 1, i t produces a primary magnetic f i e l d F^, there. This f i e l d w i l l induce currents i n the Earth, the strength of the induced currents depending on the conductivity of the Earth i n the region. I f the Earth were p e r f e c t l y conductive the f i e l d s of the induced currents may be represented by an image current, I , of exactly the.same strength as the primary current but flowing i n such a manner as to produce opposite e f f e c t s to those produced by the primary .current. Hence, with an image current I^ of equal magnitude, the induced f i e l d , F^, at the point P w i l l be of the same magnitude as. the primary f i e l d F . The resultant f i e l d at P, being the vector sum of these two f i e l d s , F^ and F^, w i l l be along the h o r i z o n t a l , with no v e r t i c a l component at a l l . The vector F z shown i n figure w i l l not e x i s t . However, with a non-perfectly conducting Earth, the image current I w i l l have a smaller magnitude compared with the primary current I so that the magnitude of the induced f i e l d at P w i l l be smaller. The resultant f i e l d at P, F , again the vector sum of R F^ and F^, w i l l now be i n c l i n d e d to the h o r i z o n t a l and w i l l therefore have a v e r t i c a l component F'. as shown i n Figure 1. C l e a r l y , then, both the resultant magnetic f i e l d F and R the v e r t i c a l magnetic f i e l d F^ depend on the conductivity of the Earth. S p a t i a l v a r i a t i o n s i n F and F w i l l , assuming a s p a t i a l l y uniform source for the magnetic disturbance, reflect conductivity variations in the Earth. The above.model is only valid for regions of.the earth that are approximately horizontally layered. The f i e l d relationships are more complex near regions of lateral conductivity variations. Now consider what happens when the magnetic disturbance varies with time. As this disturbance impinges upon the Earth, the depth of penetration depends on various factors summarised in the expression: 2 1/2 Skin Depth, d = ( ) in MKS units. v opto This expression shows that the depth at which the amplitude of the magnetic disturbance f a l l s to 1/e of i t s i n i t i a l value, the skin depth is inversely proportional to the electrical conductivity a. to the magnetic permeability of the material y, and to co the angular frequency of the magnetic disturbance. In other words, higher frequency disturbances are more rapidly attenuated with depth than lower frequency disturbances. Then i f we. consider a conductive layer, we find that the vertical variations for high frequencies are strongly attenuated (strong image currents) while low frequency variations pass through the layer and are l i t t l e attenuated (weak image currents). WORLDWIDE G.V.A.*S G.v.a.'s have been described i n many parts of the world. Some can be a t t r i b u t e d to the e f f e c t of nearby deep oceans since a deep ocean a f f e c t s geomagnetic va r i a t i o n s both as a highly conductive body (Mason 1963) and as a r e l a t i v e l y highly conductive oceanic c r u s t a l province. This e f f e c t , c a l l e d the cost e f f e c t , n a t u r a l l y accounts for only those g.v.a.'s near deep oceans. The rest of the g.v.a.'s i n the world must be due to other causes. Many explanations f o r non-coastal g.v.a.'s have been proposed. A l l of these rely on apparent e l e c t r i c a l conductivity contrasts between two areas. Hyndman and Hyndman(1968) and Caner(1970) for example, suggest hydration as a cause for increased conductivity i n c e r t a i n parts of the crust. This hydration, perhaps i n the form of i n t e r s t i t i a l water, may, as suggested by Hyndman and Cochrane(1971), i n t h e i r study of the area of the continental s h e l f of Eastern Canada, be associated with evaporite, s a l t l a y e r s . Uyeda and Rikitake(19 70) have also shown that many g.v.a.'s are rela t e d to areas of high heat flow. In the Canadian A r c t i c , two g.v.a.'s have been documented— one a t . A l e r t on Ellesmere Island f i r s t reported by Whitham et a l (1960) and the other at Mould Bay on Prince Patrick Island f i r s t reported by whitham (1963). Mould Bay i s shown i n Map 5. Both g.v.a." appear to be due to the presence of a highly conducting layer deep MAP 5 LOCATION MAP (offer Cool. Surv. Conoda, 1969 ) Known North Anwlcast crotcn <areo shaded. in the Earth's crust. The Alert anomaly involves lateral conductivity contrasts. Only the Mould Bay anomaly is examined in detail here since i t is the one to which the Mackenzie Bay anomaly is probably related. THE MOULD BAY ANOMALY The anomaly in the Mackenzie Bay area appears to be related to the Mould Bay anomaly for two reasons—the f i r s t i s that the frequency suppression characteristics of the two anomalies are similar, and the second is the proximity of the two anomalies. Before examining the data for the Mackenzie Bay anomaly in detail, a summary of information currently available for the Mould Bay anomaly is presented. Whitham (1963) reported that at Mould Bay, geomagnetic variations of short periods were severely attenuated. The energy density curves for the anomaly showed a 10:1 energy density attenuation for variations of 40-minutes period when compared to variations of 100-minutes period. Ionospheric causes of the anomaly were eliminated by normalising Mould Bay records to records obtained at Resolute Bay on Cornwallis Island which is f e l t to be in a'non-anomalous' zone. Various models were used in attempts to simulate the frequency characteristics of the Mould Bay anomaly— the one which fi t t e d best has a highly-conductive(10 ^e.m.u.) layer 20 km. thick at the bottom of the Earth's crust. Whitham suggested - 40 - thermal doming of mantle material into the crust as the cause of this layer, but this necessitated regional upwarping of the 1400°C isotherm in order to produce the required conductivity. At this temperature, ionic semi-conduction in olivine is believed to yield the required 10 e.m.u. conductivity for the model. Calculations also showed the thermal time constant of such a body i.e. the time taken for anomalous heat flow to reach the Earth's surface, or, the time required for anomalous isotherms to 5 6 develop at the surface, would be of the order of 10 to 10 years. Available aeromagnetic profiles over the area discounted basement mineralisation as the cause of the g.v.a. Finally, evidence indicates the anomaly is not accountable for by the coast effect, since, f i r s t l y , Point Barrow.in Alaska does- not.show anomalous geomagnetic characteristics such as those observed at Mould Bay in spite of the fact that Point Barrow is closer to deep ocean than Mould Bay i s , and, secondly, Mould Bay appears to be too far away :f.rom„deep, ocean to be affected by i t . Data obtained by Zhigalbv(1960) show that the effects of deep ocean (deeper than 2 km) are not noticed 130 km away. Ocean depths of even 500 metres appear to be at least 150 k m away from Mould Bay as shown in Map 5. Further work was done on the Mould Bay anomaly in 1964 by.Law e t a l (1965) who measured the heat flow at ten stations in M'Clure Strait. It was found that heat flow values in the area, - 41 - 130 km south of Mould Bay, were only 0.84 HFU or 57% of the world average, so that i f thermal doming is the cause of the Mould Bay anomaly, then the anomaly must either be non-existent 130 km south of Mould Bay, or, the thermal doming causing the anomaly 5 6 ' ' must be younger than 10 to 10 years (Quaternary), the thermal time constant for such a.doming. Later work at Pedder Point on Eglington Island(see Map 5) 100 km south of Mould Bay in the direction of the heat-^f^ow stations, indicates that the area is geomagnetically 'anomalous' (Whitham, 1965) i.e. suppression of the higher frequency magnetic variations i s present.. This, therefore, means that the Mould Bay anomaly is probably not due to thermal doming, since the regional upwarping accompanying such a doming would have to vanish in the 30 km separating the southernmost known anomalous area, Pedder Point,, and the thermally non-anomalous he at-flow stations in M'Clure Strait. Of course, the heat-flow values obtained i n M'Clure Strait .may be questionable, particularly because of the existence of very deep permafrost. Other geophysical studies have been made of the Mould Bay anomaly. Niblett (1967) reported that in a period of 2 months in 1965, a swarm of 2 000 microearthquakes occurred 15 km south- east of Mould Bay at a depth of approximately 6 km. Studies of these microearthquakes have shown their cause to be probably tectonic and not volcanic and their relationship to the Mould Bay - 42 - anomaly is believed to be highly speculative (Niblett and whitham, 1967). Other seismological studies do not show any specific results supporting the idea of thermal doming. A "MACKENZIE BAY G.V.A. Evidence for a g.v.a. in the Mackenzie Bay area derived from marine magnetic data collected during this survey is now presented; So far, i t has been shown that a geomagnetically anomalous condition exists i f geomagnetic variations recorded at one location differ markedly from those recorded at another location over the same period of time. In particular, for the Mould Bay anomaly, the g.v.a. characteristics are suppression of the vertical f i e l d which implies severe attenuation of the higher frequency components of the total geomagnetic f i e l d variations (Whitham et a l , 1960), since the main f i e l d lines are nearly vertical at this geomagnetic latitude. As mentioned earlier, during the whole of this survey, a station magnetometer was in operation on land at Point Atkinson (see Map 5 for location) approximately 150 miles from the survey area. Two other oceanographic ships were making studies i n the immediate area, particularly the CSS BAFFIN in an area north of Point Atkinson. ... .. Figure 2 shows the time-series plots of the magnetic variations recorded by the station magnetometer at Point Atkinson compared with the variations recorded at sea. More detailed plots of the two recordings were made and these are shown in Figure 3 FIGURE Z COMPARISON BETWEEN SHIPBOARD MAGNETIC VARIATIONS AND STATION MAGNETIC VARIATIONS o o o o MARINE M A S 0 I t H O U R S FIGURE 4 DETAILED PROFILES COMMRING MARINE ADO STATION MAGNETIC VARIATIONS - 46 - and Figure 4. Three features are noticed in these figures. The f i r s t feature is that in almost a l l plots shown there is remarkable correlation between the variations recorded at the two locations. The second feature is that, though there i s remarkable correlation between the variations recorded,at the two locations, the variations recorded at sea show a strong attenuation of the higher frequency components. In almost a l l cases, the variations recorded at sea are much smoother in appearance, lacking the 'spikiness' of the variations recorded at Point Atkinson. Any high frequency components of the variations evident,from Point Atkinson records that s t i l l appear in the variations recorded at sea, are strongly attenuated in amplitude. The third feature of these plots is that there appear to be phase differences between the variations recorded at the two locations., These differences do not appear to be constant. These three features are typical of a g.v.a. — i n particular, they appear to be similar to those of the Mould Bay anomaly (Whitham, 1970). Geomagnetic variation anomalies are usually investigated with three-component magnetometers. With such instruments, i t is then possible to obtain not only time-series records of geomagnetic variations but also directions can be established since a l l three components are known. In this survey, since only the Total f i e l d was measured, no directionality of the geomagnetic variations can - 47 - be determined. A l l that is known is that there is suppression of the total f i e l d in amplitude and that there is attenuation of the higher frequency components of the geomagnetic variations. The frequency characteristics of the Mackenzie Bay g.v.a. are now examined. Figure 5 shows the power spectra for the same time period of station magnetometer variations and of the marine magnetometer variations. Comparing the two curves, i t is apparent that the higher frequency, components shown in the marine magnetometer records are severely attenuated compared to those-of the station magnetometer. From power spectra such as these, an attempt to compute power ratios at various frequencies was made. Figure 6 shows the power ratios computed from selected time periods of the survey. Though substantial scatter is present, the figure does show that magnetic variations of periods around 2 0 minutes are attenuated severely compared to variations of. 1 0 0 minutes. The.power spectra were computed using the periodogram method (Jones 1965). The trend was f i r s t of a l l removed from each time period segment and end effects were minimised by tapering the end of each segment using a cosine b e l l function. Since the differences in geomagnetic variations are between .the two locations of Mackenzie Bay and Point Atkinson, the g.v.a. must l i e in the intervening region. Further delineation of the g.v.a. is suggested by data obtained by the CSS BAFFIN. When compared to the same station magnetometer records, the marine magnetic data recorded at sea by the CSS BAFFIN see Map 5 appear to show l i t t l e , or no suppression of the magnetic variations - 48 - F I G U R E 5 9 —————— P O W E R S P E C T R A o PERIOD (minutes), - 49 - < 00 § ° f— OT - •• UJ Q Z < o d < cc cc UJ «S 5 o o a. e i — 40 — r - 8 0 120 PERIOD (minutes) FIGURE 6 POWER RATIO BETWEEN MACKENZIE BAY MARINE DATA AND PT. ATKINSON STATION DATA (Srivastava, pers. comm.). This i n f e r s that the CSS BAFFIN survey area and Point Atkinson must l i e i n the same 'geomagnetic zone'. In that case the Mackenzie Bay g.v.a. must l i e between the Mackenzie Bay area on the one hand, and the CSS BAFFIN survey area and Point Atkinson, on the other. Summarising the evidence, therfore, i t i s seen that the Mackenzie Bay g.v.a. appears to have s i m i l a r geomagnetic characte i s t i c s as the Mould Bay g.v.a. From the locations of the magnetic v a r i a t i o n records examined, the Mackenzie Bay g.v.a. must l i e between the general Mackenzie Bay area and Point Atkinson. IMPLICATIONS OF THE MACKENZIE BAY G.V.A. Probably the most e x c i t i n g implications of the Mackenzie Bay are those r e l a t e d to plate tectonics. Law and Riddihough(1971) i n t h e i r study of the geographical r e l a t i o n between tectonic environments and a l l g.v.a.'s known i n the world, show that a l l g.v.a.'s not explainable by the coast e f f e c t appear to occur at plate boundaries. C l a s s i f y i n g a l l these non-coastal g.v.a.'s i n terms.of t h e i r tectonic environments, they show that a l l these g.v.a.'s f a l l into one of three tectonic environments with the exception of Japan. The tectonic environments are — " a l o n g the edge.of .stable .cratons; within f o l d b e l t s ; along major f a u l t and r i f t s t r u c t u r e s " (Law and Riddihough, 1971). Law and Riddihough add that this should not be s u r p r i s i n g since the various geological s i t u a t i o n s such as hydration of c e r t a i n parts of the crust and high heat flow regions believed to cause the e l e c t r i c a l conductivity contrasts associated with g.v.a.'s do occur p r e f e r e n t i a l l y i n the zones affected by a plate boundary. Japan appears to f a l l i nto a separate tectonic c l a s s i f i c a t i o n of i t s own, that of an i s l a n d arc. However, studies of g.v.a.'s i n i s l a n d arc s i t u a t i o n s are very sparse and Japan may be an exceptional structure. In p a r t i c u l a r , Law and Riddihough show that for North America, a l l known g.v.a.'s not a t t r i b u t e d to the coast e f f e c t e i t h e r l i e at the edge of the North American stable craton or within f o l d b e l t s . Map 6 shows t h e i r ideas. In the Canadian A r c t i c , the two previously documented g.v.a.'s do indeed f a l l i n t o one of the three tectonic environments. They l i e within f o l d b e l t s . The A l e r t anomaly l i e s within a region of "Eugeosynclinal (magmatic) f o l d i n g that sweeps across Ellesmere Island and continue i n a north-easterly d i r e c t i o n over the northern t i p of Greenland" ( N i b l e t t and whitham, 1970). The Mould Bay anomaly l i e s within another f o l d b e l t , the Parry Islands Fold B e l t . - As Map 5 shows, the edge of the North American craton appears to run northwards along the Mackenzie River, then north- eastward ,to. cut,across Banks Island and f i n a l l y eastward to the Eastern A r c t i c . That i t cuts across Banks Island i s s i g n i f i c a n t . - 52 - MAP 6 . MAP SHOWING GEOGRAPHICAL RELATIONSHIP BETWEEN GEOMAGNETIC SITUATIONS 8 TECTONICS . CRATON BOUNDARIES FROM . KING ( 1 9 6 9 ) . ( map af ter Law 8 Riddihough 1971 ) Preliminary data from g.v.a. stations occupied on Banks Island (Figure 7) by the Geomagnetic Division of the Earth Physics Branch of the Department of Energy, Mines and Resources show that a g.v.a. exists between Sachs Harbour to the south of Banks Island and Castel Bay, to the north of Banks Island. Castel Bay records show suppression of higher frequency magnetic variations so that the material underlying the Castel Bay area is of higher conductivity compared to that underlying Sachs Harbour. Looking at the location of the Mackenzie Bay g.v.a. then, (Map 5) we see that though i t lie s close to the edge of the North American craton, the edge as drawn on the map (Geol. Surv. of Canada, 1969) lie s to the south. Further work on the Mackenzie Bay g.v.a. should resolve this discrepancy by defining the extent of the anomaly better, but for now, i t appears that the craton edge does pass through the region between the Mackenzie Bay and Point Atkinson as the g.v.a. infers. Since the Mackenzie Bay anomaly, the Mould Bay anomaly and the.anomaly recorded at Banks Island a l l appear to l i e in the Parry Islands Fold Belt, i t may be speculated that a l l three are related. Again, further work in the area is necessary; i t may .then be possible to relate with more confidence, the g.v.a.'s .in the region to the tectonics. The tectonics of this region may be important in our understanding of the evolution of the Canada Basin. o o o © © 0 Mould Bay © q o o r < cr >- z us o O _j fc- o O UJ <n 3 < S c: o z O : _j i • • • t n i i i i i 1111 O e ~ 0 ° CasteS Bay • • © © © J — i m i n i i i a 111 u l 10 100 1 0 0 0 10 100 PERIOD (mins) 1 0 0 0 10 Sachs Harbour - L I I l i n n ! J ' « i i l i t too 1 0 0 0 FIGURE 7 GRAPHS SHOWING ATTENUATION AT HIGHER FREQUENCIES FOR GEOMAGNETIC VARIATIONS RECORDED AT MOULD BAY 6 CASTEL BAY COMPARED WITH SACHS HARBOUR . ENERGY DENSITIES NORMALISED TO RESOLUTE BAY . ( Graphs courtesy of L . K . Law ) CONCLUSIONS The marine magnetic data obtained i n this survey i s heavily doped with magnetic n o i s e — t h i s i s c l e a r l y seen when the records obtained at sea are compared with records obtained simultaneously on land by a f i x e d s t a t i o n magnetometer at Point Atkinson. There i s remarkable time-correlation between the two sets of data. The high frequency components of the data taken at sea are severely attenuated i n comparison with the land data. In addition, some phase displacement i s evident. The net r e s u l t i s that the noise v a r i a t i o n s monitored by the s t a t i o n magnetometer cannot be d i r e c t l y applied to the marine magnetic data as corrections. I t appears that no technique a v a i l a b l e can be used to apply these corrections to y i e l d r e l i a b l e r e s u l t s . Since l i t t l e magnetic character, i s evident amidst a l l the noise, i t i s i n f e r r e d that the Mackenzie Bay/Beaufort Sea area surveyed has l i t t l e magnetic character. This i s not s u r p r i s i n g i n view of the fac t that the area i s the s i t e of vast thicknesses of sediments. The frequency attenuation of the va r i a t i o n s recorded at sea and monitored at Point Atkinson i n the Mackenzie Bay survey area, suggest, a geomagnetic v a r i a t i o n anomaly l i e s i n the i n t e r - vening region. This g.v.a., c a l l e d the Mackenzie Bay g.v.a., appears to have s i m i l a r geomagnetic c h a r a c t e r i s t i c s as the anomaly at Mould Bay—rwhether the two anomalies are connected i s not known. - 56 - Further work on the Mackenzie Bay g.v.a. would determine this as w e l l as provide more quantitative data. Since t h i s was not a proper g.v.a. survey i n the usual sense, the cause of the Mackenzie Bay g.v.a. cannot be determined. But i t i s i n t e r e s t i n g to note that i t l i e s i n the region thought to be where the edge of the North American i s presently located. The r e l a t i o n s h i p of this anomaly to i t s tectonic environment adds strength to the concept that g.v.a.'s tend to occur i n the zones affected by plate boundaries, since, i t would appear, such zones among a l l others should provide the necessary tectonic and geological s i t u a t i o n s conducive to. the formation of zones of contrastin e l e c t r i c a l c o n d u c t i v i t i e s thought to cause g.v.a.'s. From the experiences of this survey, i t i s suggested that a l l magnetic surveys conducted i n the as yet i l l - d e f i n e d areas affected by the Mackenzie Bay g.v.a. or any of the other A r c t i c g.v.a.'s f o r that matter, be treated with great care e s p e c i a l l y with regard to correction of the data for the large amplitude.magnetic noise variatons so common i n the A r c t i c . For marine surveys, a buoy .or. sea-floor station, magnetometer located within the .survey. area .may give the most r e l i a b l e data f o r use i n these corrections. - 57 - BIBLIOGRAPHY Barrett, D.L. (1968), Frequency modulation of a Shipborne Proton Magnetometer signal due to the hydrodynamic instability of the towed vehicle, J. Geophys. Res., 7̂3, 5327-5334 (Bedford Institute Contribution No. 110). Barringer(1970), Manual for Barringer Oceanographic Magnetometer Model OM-104, Barringer Research Limited, 304 Carlingview Drive, Rexdale, Ontario. Bigelow, H.W. (1963), Electronic Surveying: Accuracy of Electronic Positioning Systems. J. Surv. Mapping Div., Amer. Soc. C i v i l Engs., 37-76, October. Bullard, E.C. (19 70) Geophysical Consequences of Induction Anomalies. J Geomag. Geoelect. 22, 73-74. Cain, J.C. (1965) Goddard Space Flight Center, Maryland, Report No NASA TM-X-55379/X-612-65-400. Caner, B. (1969) Long Aeromagnetic Profiles and Crustal Structure in Western Canada. Earth Plan. Sci. Letts., ]_, 3-11. Caner B. (1970) El e c t r i c a l Conductivity Structure in Western Canada and Petrological Interpretation, J. Geomag. Geoelect., 22̂ , 113-129. Chamney, T.P.(19 71) Tertiary and Cretaceous Biostratigraphic Divisions in the Reindeer D-27 Borehole, Mackenzie River Delta.,Geol. Surv. Canada Paper 70-30. CHS.(1970), Calibration Data for Decca Navigation Chains used in Hydrographic Survey of the Mackenzie Bay/Beaufort Sea area- CSS PARIZEAU 1970. File No. WA-10070. Canadian Hydrographic Service, Victoria, B.C., Canada. Churkin, M. (1969) Paleozoic Tectonic History of the Arctic Basin North of Alaska., Science, 165 549-555. Demenitskaya, R.M. and Karasik, A.M. (1965)., Magnetic data confirming that the..Nansen-Amundsen.Basin., is of normal oceanic type - i n , Continental Margins and. Island Arcs, Geol. Surv. Canada Paper 66-15. Dietz, R.S. and Shumway, G. (1961) Arctic Basin Geomorphology. Geol. Soc. Amer. Bull., _72, 1319-1330. Eardley, A.J. (1960) History of Geologic Thought on the Origin of the Arctic Basin,-Geology of the Arctic, J., G. 0 . Raasch, Univ..of Toronto Press. - 58 - Geological Survey of Canada (1969) Tectonic Map of Canada, Geology and Economic Minerals of Canada, R. J. W. Douglas. Heezen, B.C. and Ewing, M. (1960) The Mid-Oceanic Ridge and i t s Extension through the Arctic Basin, Geology of the Arctic, G.O. Raasch, Univ. of Toronto Press. Hope, E..R. (1969) Geotectpnics of the Arctic and the Great Arctic Magnetic Anomaly, J. Geophys. Res., 6̂4_, 407-427. Hyndman, R.D. and Cochrane, N.A. (1971) Ele c t r i c a l Conductivity Structure by Geomagnetic Induction at the Continental Margin of Atlantic Canada. Geophys. J., 25. Hyndman, R.D. and Hyndman, D.W. (1968) Water Saturation and Electrical Cnnductivity in the Lower Crust. Earth Plan. Sci. Letts., 4_, 427-432. Johnson, G.L. and Heezen, B.C.(1967) The Arctic Mid-Oceanic Ridge. Nature, 215, 724-725. Jones, R.H. (1965) A Reappraisal of the Periodogram in Spectral Analysis. Technometrics, _7, 531-542. Kerr, J.W. (1967), Nares Submarine Rift Valley and the Relative Rotation of North Greenland, Bull. Canadian Petrol. Geol., 15, 483-520. King, D.B. (1969) The Tectonic Map of North America, U.S. Geol. Survey, 1:5,000,000. King, E.R., Zietz, I., and Alldredge, L.R. (1969) Magnetic Data on the Structure of the Central'Arctic Region^ Geol. Socr. Amer. Bull., 77_, 619-646. Law, L.K. and Riddihough, R.P. (1971), A Geographical Relation between Geomagnetic Variation Anomalies and Tectonics. Can. J. Earth Sci., 8, 1094-1106. Law, L.K., Paterson, W.S.B., and Whitham, K. (1965), Heat Flow Determinations in the Canadian Arctic Archipelago. Can. J. Earth Sci., 2, 59-71. Law, L.K., DeLaurier, J., Andersen, F., and Whitham, K. (1963), Investigations during 1962 of the Alert Anomaly in Geomagnetic Variations. Can. J. Phys., 41, 1868-1882. Mason, R.G. (1963), Spatial Dependence of Time-variations of the Geomagnetic Field at Oahu, Hawaii, Trans. Amer. Geophys. Union, 40^(abstract only). - 59 - Morley, L.W. (1963) The Areal Distribution of Geomagnetic Activity as an Aeromagnetic Survey problem near the Auroral Zone. Trans. Amer. Geophys. Union, _34, 836-840. Niblett, E.R. and Whitham, K. (1970) Multi-disciplinary studies of the Geomagnetic Variation Anomalies in the Canadian Arctic. J. Geomag. Geoelect., 22 99-111. Niblett, E.R., Whitham, K., and Caner, B.(1967), Ele c t r i c a l Conduc- tiv i t y Anomalies in the Mantle and Crust in Canada, The Application . of Modern Physics to the Earth and Planetary Interiors, S.K. Runcorn, NATO Advanced Institute Conference at Newcastle-upon-Tyne, England. Ostenso, N.A.(1962) Geomagnetism and Gravity of the Arctic Basin, Pro- ceedings of the Arctic Basin Symposium at Hershey, Philadelphia on October 1962, Co-ordinated by J.E. Sater, Arctic Institute of North America. Packard,: M.E. .,(1954) Free Nuclear Precession Magnetometer. Varian Associates, Palo Alto, California, March 19. Parkinson, W.D...(1964) Conductivity Anomalies in Australia and the Ocean Effect, J. Geomag. Geoelect., 15, 222-226. Riddihough, R.P. (1971), Diurnal Corrections to Magnetic Surveys - An Assessment of Errors. Geophys. Prospecting, 19_ 551-567. Rikitake, T. and Whitham, K. (1964), Interpretation of the Alert Anomaly in Geomagnetic Variations, Can. J. Earth Sci., 1, 35-62. Rikitake,„.T. (1966) Electromagnetism and the Earth's Interior 1_, Developments, in Solid Earth Geophysics, Elsevier, Holland. Roden,- R. B. (1964) The Effect of an Ocean on Magnetic Diurnal Variations, Geophys. J., J3, 375-388. Schmucker, U. (1964.) , .Anomalies ..of .Geomagnetic Variations in the . Southwestern .United States, . J... Geomag... Geoelectr., 15, 193-221. .Schmucker, U. (1970) An Introduction to Induction Anomalies, J. ' Geomag. Geoelect. , 22̂ , 9-33. Sykes, L.R. (1965) The Seismicity of the Arctic, Bull. Ses. Soc. Amer., 55, 519-536. - 60 - Tailleur, I. (1969) Speculations on North Slope Geology. O i l • Gas J., 215, sept 22. Untiedt, J. (1970) Conductivity Anomalies in Central and South Europe. J. Geomag. Geoelectr., .22,.131-149. Uyeda, S. and-Rikitake, T. (1970) El e c t r i c a l Conductivity Anomaly and Terrestial Heat Flow. J. Geomag. Geoelectr., 22, 75-90. Vogt, P.R. and Ostenso, N.A. (19 70) Magnetic and Gravity Profiles across - the Alpha Cordillera and their relation to Arctic sea- floor spreading. J. Geophys. Res.;_75, 4925-4937. Vogt, P.R., "Ostenso, N.A. and Johnson, G.L. (1970) Magnetic and Bathymetric .data bearing on sea-floor spreading north of -. Iceland. J. Geophys. Res., ]5_, 903-920. Whitham, K. (1963) An Anomaly in Geomagnetic Variations at Mould Bay in the Arctic Archipelago of Canada. Geophys. J., j5, 26-43. Whitham,. K. (1965) Geomagnetic Variation Anomalies in Canada. ... J. Geomag. Geoelectr., 17, 481-498. Whitham, K. and Andersen, F. (1962) The Anomaly in Geomagnetic Variations at Alert in the Arctic Archipelago of Canada. Geophys. J., 7_, 220-243. Whitham, K. and Niblett, E.R. (1961) The Diurnal Problem in Aeromagnetic surveying in Canada. Geophysics, 26_, 211-228. Whitham, K., Loomer, E.I. and Niblett, E.R. (1960) The Latitudinal Distribution of Magnetic Activity in Canada. J. Geophys. Res., '65, 3961-39 74. Wold, R.J., Woodzick, T.L. and Ostenso, N.A. (1970) Structure of the' Beaufort Sea continental margin. Geophysics, 35 , 849 - 861. Zhigalov, L.N. (1960) Some features of the Variation of the Geomagnetic Vertical component in the Arctic Ocean. Translated from Geomagnetic Disturbances(Collection of Articles No. 4 relating to Section 3 of IGY Program), Academy of Sciences, Moscow, by E.R. Hope. Directorate of Scientific Information Services, Defence Research Board Canada. DRB Translation T 358R. - 61 - APPENDIX I DECCA 6F NAVIGATION SYSTEM CHARACTERISTICS Frequencies: Red (Pattern 1) 355.92 kHz Green (Pattern 2) 266.94 kHz Propagation Speed 299 650 km/sec. Decca Master (Hooper Island) 69° 41' 32.186"N 134° 55' 53.786"W Decca Red(Point Atkinson) 69° 41' 32.186"N 134° 55' 43.786"W Decca Green(Herschel Island) 69° 34' 07.947"N 138° 54' 53.706"W Base-line lengths: Master-Red 137 482.2 m. Master-Green 155 387.8 m Zone 8 N 7 731 381.78 Zon E 502 649.21 Zone 8 N 7 762 342.307 E 636 554.457 Zone 8 N 7 722 501.814 E 347 563.076 DECCA MINIFIX NAVIGATION SYSTEM CHARACTERISTICS Frequency 1702 kHz Propagation speed 299 Master (Shingle Point) Slave I(Kay Point) Slave II(Pitt Island) 650 km/sec. 69° 00' 01.497" N Zone 8 137° 28' 49.528" W 69° 05' 03.893" N Zone 8 136° 07' 32.287" W 69° 15' 55.932" N Zone 8 138° 19' 56.160" W N 7 656 233.87 E 400 817.93 N 7 664 007.32 E 455 153.98 N 7 687 375.22 E 368 354.65 Baseline lengths Master - Slave I 54 907.60 metres Master - Slave II 44 995.60 metres - 63 - APPENDIX II TABLE OF COMPUTER PROGRAMS PTAPE DECODER DECNAV + DECCA + DISTAN + MINTY + UNMINT MAGNAVM + IGRF + TMINT + UMIN GRID + MXGEN PLOTTER + MXPAND + PLOT2D TRACKER SMPLOTTER ONEDEE The following section gives b r i e f notes concerning the above programs. - 6 4 - PROGRAM COMMENTS PTAPE DECODER This program reads i n Friden-encoded data, checks for complete- ness and correctness of a whole data unit (one minute's data), decodes the characters, forms data words from these characters, and outputs the data words i n EBCDIC (numeric decimal characters), see Flow Chart 2, DECNAV +-SUBROUTINES The main program, DECNAV as shown i n Flow Chart 3 , reads i n the Start/End Times, the Decca co-ords f o r the Start/End, the Decca navigation system i n use (6F or M i n i f i x ) and the type of track run ( s t r a i g h t l i n e or hyperbolic) for each l i n e . I t computes/ interpolates between the Start/End of the l i n e and outputs Times and Geographic/UTM co-ordinates at s p e c i f i e d time i n t e r v a l s . The i n t e r p o l a t i o n s performed are e i t h e r l i n e a r f or a s t r a i g h t - t r a c k or hyperbolic f o r a hyperbolic lane-run. The .subroutine DECCA i s adapted from a version generously loaned by the Canadian Hydrographic Service (now the Marine Sciences Branch, Department of Environment). DECCA converts Decca co-ordinate .readings i n t o Geographic or UTM co-ordinates. The subroutine DISTAN computes the distance i n n a u t i c a l miles, between two points given the geographic co-ordinates of these points. _ 6 5 _ The subroutine MINTY converts the Time parameters recorded during the survey,. Sequential Day/GMT Time (e.g. Day 2 6 7 , Time 2 3 4 5 hours), into a more manageable s i n g l e quantity for computing purposes, Sequential Minutes. The subroutine UNMINT undoes what MINTY does - namely, i t converts Sequential. Minutes back into Sequential Day/GMT Time. This i s done purely because Sequential Minutes are very large numbers which do not-lend themselves to easy reading, and because Day/time are used.in the ship's operations. MAGNAVM + SUBROUTINES The main program, MAGNAVM, reads i n the Magnetic Data (Day/Time/ Mag) on the one hand, and the Navigation Data (Day/Time/Co-ordinates) on the other. I t then matches the two sets of data on the basis of the time parameter (Day/Time). Flow Chart 4 shows how this i s done. MAGNAVM c a l l s the subroutine IGRF which computes the Regional Magnetic^ F i e l d (IGRF value) at a point given the Geographic co-ordinates of that point. The two other subroutines that MAGNAVM c a l l s , , subroutines TMENT and UMIN, are the real-number versions of the previously-mentioned subroutines MINTY AND UNMINT respectively. - 66 - GRID + SUBROUTINE MXPAND The main program, GRID, sets up the data, X-Y co-ordinates of the scattered data points, so that they are ready to be gridded onto a square-grid necessary for p l o t t i n g . The gridding i s done by the subroutine MXGEN which 'remembers' how i t generates this g r i d a f t e r i t has done i t once. This 'memory' i s fed to the subroutine MXPAND used i n the next stage of processing. MXGEN and MXPAND are both programs written and generously loaned by Mike Patterson of the Department of Geography of the U n i v e r s i t y of B r i t i s h Columbia. PLOTTER + SUBROUTINES The main program reads i n the Z value (may be T o t a l F i e l d reading f o r instance) f o r the scattered data points fed i n t o the above Main Program GRID- Since the subroutine MXGEN, used i n con- junction with GRID, remembers how to generate the g r i d , and passes t h i s information to the subroutine MXPAND, MXPAND merely reads i n the Z co-ordinate and places i t i n an appropriate l o c a t i o n i n the square g r i d to be generated a f t e r weighting t h i s Z co-ordinate according to ...the' gridding information,, This 'remembering' of the gridding procedure r e s u l t s i n having to a c t u a l l y g r i d the scattered data points j u s t one — because once the.gridding information i s recorded, any set of Z co-ordinates f o r the same scattered data points can be gridded very quickly. As an example, gridding 6 700 scattered data points onto a 50 by 50 square g r i d s u i t a b l e f o r p l o t t i n g takes approximately 500 seconds of CPU - 67 - time for the UBC IBM System/360/67. If this gridding had to be done for say, three sets of Z co-ordinates e.g. Total Field, Regional Field, and Anomalous Field, the amount of computer CPU time would be 1500 seconds CPU time. However, using MXGEN/MXPAND and 'remembering' the gridding pro- cedure results in 500 seconds CPU for gridding the f i r s t set of Z co-ordinates but only 1„5 seconds CPU for gridding each subsequent set of Z co-ordinates. After gridding via MXPAND, the main program PLOTTER calls the subroutine PL0T2D which plots and contours the data-grid. PL0T2D was written by Dr. T. J. Ulrych of the Department of Geophysics of the University of British Columbia, who unselfishingly loaned i t . The contouring routines called by PL0T2D are those available at the University of British Columbia. PLOTTER generated the maps shown as Map 1 to Map 4. TRACKER TRACKER plots the ship's positions for the whole cruise. A position every minute or a position every 'n' minutes are plotted where 'n'-is selected by the user. For this cruise, a position every 10 minutes was plotted as seen in Map 1. - 68 - SMPLOTTER SMPLOTTER merely plots selected periods of station magnetometer data.. The periods .are selected by the user who supplies the program with the station magnetometer data, usually on magnetic tape. SMPLOTTER scans the data for, and plots, the periods selected, along with the appropriate axes etc... The station magnetometer traces in Figure 3 and Figure 4 were generated by this program. ONEDEE ONEDEE reads from the user, instructions as to which marine magnetic lines(traverses) are to be plotted in profile. It scans an input tape containing marine magnetic data for a l l lines, picks out data for the line selected, and scales/plots the data for that line in time-series. Profiles of marine magnetic data shown in Figure 3 and Figure 4 were plotted by this program. - 69 - F L O W C H A R T 2 P R O G R A M ' P T A P E - D E C O D E R ' - F L O W C H A R T ( S T A R T ) If end-of-f l le or end -o f - tape encountered Z t r o r e i f o f o / p Mock Write Mock on o / p tape Pr in t p a p e r - t a p e t t a t l s t i c t e-o-t Scan paper tape frames Read rest of 6 0 - frame orroy Form data numbers Check mag reading is within limits Average mags over number valid Move F i l l ) to star l ing position If Ooy or Time w o r d , • 9 9 9 9 . If Mag w o r d , • OOOO. Print spot check Write decoded data on o / p tapes in blocks ( S T ° P ) - 70 - FLOW CHART 3 PROGRAM 'OECNAV - FLOW CHART ( $™T ) l/P Lin* Onto* 0*l*rmint OECCA L O M trovtrt*d Compute Point Along Lon* a Olttoncts B«tM*n Thorn Compute Lin* Tlmo/ Lmgtti a ShipSpMd Interpotol* Botwtcn PotHlont Along Low Sbctn DISTAN Sortn O E C C A PrinI Snip Spot*1 Sbrln OECCA Convert Start End OECCA Co-ordt lo UTM/Gtog Co-ordl Compute Lin* Tlmt/ Length a Ship Spttd Intorpoloto Llfttorly Print Ship Spttd , O/p Inttrpoloted TlrMt, UTM a Gaog Co*ordt Bock to START... . ^ Q U I T ^ Un* Ooto UP Storl Tim* a OECCA Co.ordt End Tlmt a OECCA Co.ordt FLOW CHART 4 PROGRAM 'MAQNAVM' • FLOW CHART ^ S T A R T ^ \ HEAD IN / I k l V OATA / S M T P , TMWT CONVERT M V O/T TO "MINUET* t succcssrvf CHOFUS *t*0 \ HEAD m I \ OAO DATA / CONVERT MAO O/T TO 'MINUET' MMMJCT • NMINVET MATCH MAOE LOAO DATA INTO O/P ARRAY COMPUTE I0RF • ANOM OCT R E I T . MMfNUET • NMMUCT c MOO UP ' HAVWATfON DATA - DAY • TWC * I T CO-0*0* MAOMCTK DATA • OAT* T t M • TOTAL PKLO MAO « A O M S PROS O/P • MATOVD OAT • TMtt • » - T CO-CMOS • TOTAL F«LO MAS M A D A M * COMPUTED HQMMAL DC*FI • ANOMALOUS IAMOM1 FIELDS A M A E VIATORS • D/T * OAT * TIME MINUET • SEOUCMTUL MSN/TC COUrVALEMT OP CAT • TNCE MMfWUCf * M M OATA MMUfT MMMUET • M V DATA MINUS T - ZL - APPENDIX III This contains.the source listings o f . a l l the programs used in ..the reduction of data f o r - t h i s survey,, with the. exception of the'Subroutines MXGEN and MXPAND which were written by and .available only from Mike' Patterson of- the Department of Geography at the University-of British Columbia. A...table' of .all the computer programs .can be. found at the beginning .of 'Appendix-, II, while Flow Charts for "three of the major .programs- can be found at the latter part of the same Appendix II. C M P >>>>xxxxxxx>)<>>xxxxxxx.xxxxxxxx>>>)i>x){X)ixxxxx)!X>>>>>>>>y>>>>>)!X>y>>>>>>>>>>x RFS NO. C40274 UNIVERSITY CF B C COMPUTING CENTRE MTS(AN192 * * COMPUTING CENTRE WILL BE OPEN EASTER HOLIDAYS , £AM TC 5PM * * * = F I L E FOR OELI VERY = F ILE FCP OELIVEFY = F ILE FOR CEL I VERY = F ILE FOR DELIVERY * * * * * * * * * * * * * * * * * * * * * PLEASE R £ T UR N TC GEOPHYSICS DEPARTMENT * * * * * * * * * * * * * * * * * * * * SSICNON RGOH T=3C 9=15 COPIES=4C PRIO=L * * L A S T SIGNCN WAS: 1 0 : 5 4 : 1 5 THU MAR 3 C / 7 2 USER "RGOH" SIGNEC ON AT C 8 : 3 6 : 1 0 CN FRI N AR 3 1 / 7 2 $COPY *SOURCE*3-«CC * S I N K * C * * * * * * * * * * * * * * * * * * PROGRAM 'PTAPE C ECODER * * * * * * * > ! * * ; : * * * * * * * * * : * * * * * * C * * T H I S FRCGRAM DECCCES FPICEN-CCCEC PAFEPTAPE AMBERS INTO DECIMAL NUMBERS C PERFORMS VARIOUS CHECKS, AVERAGES THE CATA £ WRITES THE C/P CN COMPUTER-TAPE. C WRITTEN FOR MARINE-MAG LATA - CAY,TIME,1G MAGS. RCCQLE GCH UBC JUNE. 1 <S7 1 . C * * * * * * « * * * * * : t * : M * * * * * * * * * * * * * * * * * * * ^ C P C N T = ( I / P ) PAPERTAPE FRAME CCUNT. CCNT=(C/P) CATA-PC1NT COUNT WITHIN C AN O/P BLOCK!SIZE SET BY OCNT M A X . ) . FCR EACH PAPERTAPE, G IS THE NO. C CF C/P ELCCKS SC THAT TrE TCTAL NC. OF CATA-PCINTS O/P FOR THAT P-TAPE, C ( T C C N T ) , IS GIVEN BY: TCCNT = ( { C - l ) * E L K S I Z E ) + CCNT(FOP LAST ELCCK) C I N E 4 C H MINUTE OF P TAPE, THERE ARE FPM F R A M E S / M I N I T E , WPM CATA-WORDS/MIN. C WITH TMAG MAG-REACINGS OF WHICH PERHAPS VMAG ARE V A L I D ! M A G S ) . C FCP THE PA PERT APE , THERE ARE FFCP FPAMES/CATA-FCINT(WHICH INCLUDES THE C SEPARATOR-FRAME) OF WHICH FPW FRAMES MAKE LP A LATA WORD. C F l l IS A CCUNT WHICH IS INCREMENTED EVERY TIME A F i l l ) CHARACTER IS FGUNC C WHETHER THE CATA FOLLOWING IT IS VALIC OR NCT. C THE F( ) € T( ) ARRAYS IN NAMELIST STORE THE FRIOEN-CODE CHARACTERS AND C THEIR CORRESPONDING TRUE!DEC IMAL) NUMBERS RESPECTIVELY. C CFARl ) IS AN ARRAY CONTAINING SUCCESSIVE CHARACTERS THAT MAKE LP A NUMBER C EACH OF WHICH IS STORED IN A NUMBER! ) ARRAY, WFM LCNG . THE NUMBERS ARE C MANIPULATED AND THEN O/P INTO THE DA TA( ) ARRAY WHICH IS C/P CN MAGTAPE. C CAT A( ) IS THE FINAL ARRAY INTO WHICH THE DATA IS PLT PRIOR TO O/P ON MAG C TAPE. ITS LCCATIONS CONTAIN CAY, TIME S AVMAG IN SUCCESSIVE LOCATIONS. NC C OTHER DATA IS O/P ON THE MAGTAPE. A \MAG=AVERAGE CF 1 MINUTE'S MAG-REACINGS. C A DATA-POINT IS DEFINED AS A NUMBER DESCRIBING A DATA PARAMETER BE IT DAY C CR TIME OR AVMAG. SC, CCNT, THE CATA-POINT CCUNT, UPS IN THREES FOR EACH C MINUTE OF DATA CECCDED AND C / F . C FRAME{ ) IS ARRAY CONTAINING 1 MINUTE'S PAPERTAPE FRAMES C C L M M ( ) £> FRIMEI ) APE CTHEP ARRAYS OF THE SAME SIZE AS FRAME ( ) . C OL I M='TOTAL NO. OF MAG-REACINGS FCUNDdN A PTAFE) CUTS ICE L I M I T S S P E C I F I E D . C BUM F=TOTAL NO. OF PAPER TAPE FRAMES FOUND INCECCDEABLE(IN A P T A P E ) . C C ^ s ^ M ^ + O/p ELCCKSIZE - OPTIMUM BLCCKSIZE FOR UBC IBM 3 6 0 / 6 7 IS 4C96 BYTES. C VRITE FORMAT FCR C/P TAPE=I5 PER CATA-WCRD. V.E HAVE 3 C AT A-W CRDS {D AY, C TIME 6 AVMAG) PER DATA-SET, HENCE 15 BYTES. SO MAX• BLCCKSIZE = 4 0 9 6 / 1 5 C =27C CATASETS (MINS. -4HR.32M. INS) . SC SET 0 CN T = 2 7 C * 3 = 81C MAX. C C * * * 4 4 * 4 * D 0 N ' T FORGET - ASSIGN O/P MAGTAPE TO I / O UNIT 3 ! ! ! ! ! ! ! ! ! ! ! C I M P L I C I T INTEGERS (A-Z ) CIMENSICN C F A P ( 4 ) , NUMEER (12 ) , F U 2 ) , T ( 1 2 ) , F P A ME ( £ C ) , F R I M E U C ) , + D U M M ( 6 0 ) , D A T A ( f i l C ) C I / P CATA CONSTANTS DATA F P W , F P C P , F P M , T M A G , W P M , F ( l ) , F ( 2 ) , F ( 3 ) , F ( 4 ) , F ( 5 ) , F ( c ) , F m , F ( 8 ) + , F ( 9 ) ,F ( 1 0 ) , F ( 11) , F ( 1 2 ) , F ( 1 3 ) , T ( 1 ) , T ( 2 ) , T ( 3 ) , T < 4 ) , T ( 5 ) , T ( 6 ) , T ( 7 ) , *T (8 ),T (9 ),T ( IC ) ,T( 11 ), T( 12 ),T( 13) / 4 , 5 t 6 G , IC, 12 ,1 , ? , 1 9 , 4 , 2 1 , 2 2 , 7 , 8 . + 25 , 3 2 , 1 2 8 , 9 8 , 8 4 , 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 0 , 1 2 6 , 9 8 , 8 4 / * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ^ * * * * * $ * * * * * * * * **********************<:} * C 98 c c PTNO=20 SET BUMF=0 PCNT=G F 11 = 0 C = l CLIM=C UP CCUNTS FOR EACH PAPERTAPE PROCESSED C********SET CCNT UPIQCNT CHECKED TO SEE IF 0/P BLQCKSIZE REACHED) C CCNT=C UMIL FIRST MINUTE'S GOOD DATA F CUND(SEE 142 £ 17C) ICC OCNT=C C C***4****SCAN PAPERTAPE FOR F( 1 1) CHARACTER 101 CALL FTAFE( IFFAME,fill,£21 ) PCNT=PCNT+1 1C2 K=l 104 FRAME(K)=IAES (IFRAME) IF(FRAME (K).EC.F(U) ) GC TC 106 C F ( l l ) NCT FCUND. SCAh AGAIN. (PRINT MSG IF- T U S IS NCT START OF PTAPE) C (MSG NOT PRINTED IF FRAME (K ) = C WUCH IS GENERATED BY BLAf\K PAPERTAPE) IF ( F R A ME ( K ) . E C. C) GC TC 1 C 1 IF (OCNT.GT. C) V i R I T E(c,7) F RA E ( K ) , CCNT, NLMBEF(l), NUMEEP(2) FOUND • 14, ' - C- C 1C6 1 FORMAT (IX, 'LOST F l l + AFE SECT ICN . CCNT=» , +****! ) GO TO 101 F ( l l ) FOUND. PRINT KEEPING PCM GCING Fl1=F11+1 I F ( F l l . G T . l ) GO TD 1C7 WRITE( 6, 1 ) PTNO, PCNT » PAPERTAPE •, 15) , 15, ». A F F R O X NC D A T A L O S T I F DAY 14, ' / T I M E END 15 CF PAPERT * * * * MSG S READ IN REST CF FRAMES FOR 1 MINUTE OF DATA NC I2/1X, 'FIRST F ( l l ) CHARACTER FO + UN C AT FRAME NO. 107 CO 12 0 K=2, FPM CALL PTAPE(IFRAME,fill , S2 1 ) FRAMEIK ) = IABS(IFRAME) PCNT=PCNT+1 120 CCNTINUE m h HAVE 1 MINUTE'S FRAMES. CHECK 13C IF(FRAME(FPCP+1).NE.F( 12 ) ) GC TO 142 M=W FM-1 SEPARATORS PRESENT 139 DO 139 N = 2,i1' L=(FPDP*N )+ 1 I F ( FRAME (L ) .NE CCM INLE GO TO 16C F(13)) GO TO 142 GOOFED LP. BOMB UHCLE PROGRAM IF FCNT.GT.6C0 £ STILL NC GCCC DATA FCUNC VET. CTFERMSE SCAN INSIDE ARRAY FOR F ( l l ) TC RESTART. TEST FCP BOMB-OUT ONLY MADE FCF START CF PT APE( I.E. ELOCK 1) IF(C.GE . 2 ) GO TO 143 IF(PCNT.GE.600.ANC.OCNT.EG.C ) GO TO 4CC DO 144 J=2,FPM IFIFRAME(J).EG.F( 11)) GO TO 147 COM I HUE C*** * ****SEPARATORS C C 14 2 14 3 144 C F i l l ) NCT IN ARRAY - PRINT MSG 6 RESTART SCAN CF PTAPE FOR F ( l l ) V«R I IE ( 6 *S 1 CCM, NUMBER(l), NUME ER(2) , FRAME 9 FORMAT(IX, 'SEPARATORS GOOFED S F l l NOT IN ARRAY. CNE MINLTE 1 ' S DA + TA LOST AT CCNT=«, 14, « - AFPRCX CAY', 14, '/TIME*, 15, ' ****** +****./IX, "GCCF IS IN THIS ARRAY .....'/IX, 30I4/1X, 3014) GO TO 101 C F ( l l ) IN 4PRAY. UP F l l COUNT. SHIFT ARRAY SC J IN 1ST ARRAY LOCATION C LSE DUMM( ) FOR TEMPORARY ARRAY. PRINT MSG, LOCATION S GCCFEC ARRAY 147 F11= F11 + 1 WRITE(6,8) CCNT, NUMEERU), NUMBER (2 ), FRAME £ FCRMATdX, 'SEPARATORS GCCFEC £ F l l IS IN ARRAY. CNE MINUTE' 'S CAT +A MAY BE LOST AT CCNT=«, 14, « - AFPRCX CAY', 14, »/TIME», 15, • + * * * * * * i / l X , 'GCCF IS IN THIS ARRAY «/lX, 3CI4/1X, 3CI4) CO 148 JJ = 1, FFM 148 DUMM(JJ)=C JJ=1 DC 149 NN=J, FFM D U M M (J J ) =F R A M E( N N) JJ=JJ+1 149 CCNTINUE M=FPM-J+l J J = l DO 151 N=1,M FR A (" E( N )=CUMM (JJ ) JJ=JJ+l 151 CONTINUE C READ IN SOME MORE FRAMES TO FILL ARRAY. THEN CHECK SEPARATORS AGAIN. L=FPM~J+2 DO 153 K=L,FPM CALL PTAPE(IFRAME,S11,S21 ) FRAME(K) = IAES(IFRAME) PCNT = PCNT+1 153 CONTINUE GO TO 13 0 C C********SEPARATCRS C.K. SET F R IM E( )=FFAME ( ) : FR IME( ) USEC FOR SPOT-CHECKS C LP OCNT, PRINT MSG IF CCNT=1 - THEN CECCCE CATA FRAMES. 16C CO 165 P=l, FPM FR IME(P)=FRAME(P) 165 CONTINUE 17C 0CNT=0CNT+1 IF( CCNT.CT.l .OR.Q.GT.l ) CO TC 17 1 TCNT = PCNT-FPM+1 WRITE (6, 2) F l l , TCiMT 2 FCRMATdX, 'FIRST MINUTE WHERE SEPARATORS C.K. AFTER 15, • F l l + CHARAC TER S FCLNC - AT FRAME NC. ', 15/) C SET IP VALID-MAG CCLNT fcFICH CROPS AS EACH INVALID MAC- FCUNC 171 VMA G=TMAG C C****4***DECCDING . C TACKLE ALL WORDS IN CNE MINUTE. 172 CO 199 1=1,WPM JZ = ( I*FPCF) IZ=JZ-(FPDP-2) C TACKLE EACH FRAME, STORE IN WORD ARRAY FORMING NUMBERS FROM WORDS C AS EACH WCRO STORED. M=l DO 177 K= IZ, JZ C HERE IS THE KEY DECODING LINE - FIND WHAT FRIDEN CHARACTER EACH FRAME C IS £ THEN SET FRAME TC CORRESPONDING TRUE(CECIKAL ) NUMBER. DO 174 J=1,1C IF(FRAME(K).EG.F(J) ) C-0 TO 176 174 CCNTINUE C FRAME NCT CECODEAELE - IhVALID CHAPACTER(P1 APE PUNCHING ERROR?) C N GTE I C CNT ROLL E C EV STATEMENT 171 C (A) IF MAG-FRAME, ZERO feHCLE WCPC (NUMEER ( I ) S CROP VALIC-MAG COUNT ECNT=PCNT-FPM+K IF( I . L E . 2 ) GO TO 175 WRITE(6,10) FRAME(K), ECNT, CCNT, NUMBER( 1 ) , NUMBER I 2) IC FCRMATdX, ' F PI C EN CHARACTER' , 15, • I N V A L I C : M A C— F P AM E NC . • , 17, • + - OCNT I S 1 . 14, '. MAG-READING ZEROED. AFFROX DAY*, IV, '/TIME', +15 , • ******* » ) NUMBER (I ) = C VMAG=VMAG-1 BUMF=8UMF+FPW GC TC 199 C (B)IF DAY CR TIME FRAME, 9999 WFCLE WCRC 6 CONTINUE NEXT WORD 175 WRITE(6,3) FRAME(K), ECM, CCNT, NtMBEP(l), NUI»BEP<2) 3 FORMAT(IX, •FRIDEN CHARACTER', 15, • I NVALID:DAY/TI ME FRAME NO.', +17, » - CCNT IS*, 14, CAY/TIME SET TO SS99. APPROX DAY', 14, •/ + T IME ' , 15, ' ****** ) NUME ER ( I )=9999 BUMF=BUMF+FFW GO TO 199 C FRAME CECCDEABLE. SET FRAME TO TRUE NC. 6 FC FM WORC FROM CHARACTERS. 176 FR AM E (K ) =T ( J ) CHAF(M)=FRAME(K) M = M+ 1 177 CCNTINUE C C********CONVERT CHAP ARRAY INTC SINGLE NUM EER (AUTO SKIPPED IF NUMB ER = 0 OR c.999) C GET LAST CIGIT NUMBER ( I )=CHAR ( FPW) C NCW GET OTHER CIGITS. NCTE '!• CONTROLLEC EY DO STATEMENT 171. TEMP=FPW-1 DO 18 2 Z=l, TEMP FNC=FPW-Z NUMBER (I )=NLMEER(I)+(CFAR(FNC)*(10**Z)) 182 CONTINUE C C**4444**NCW CHECK M AG-REAC INC-S WITHIN CHOSEN LIMITS SO BAD VALUES REJECTED C FOR M AC 8A Y, H I - L I M I T = X 9C C C GAMMAS, LC-L 1 MIT = X7500 GAMMAS(UNDERSTOOD X=5) 187 IF( I.LE.2 ) GO TO 199 IF(NUMBER( I ) .GT .9000 .CP .NUMEER ( I ) .LT.750C ) GO TO 192 C MAG-RE AC I NG INSICE LIMITS - C.K. GO TO 199 C MAG -READING OUTSICE LIMITS - ZERO MAG, DRCP VMAG-CCLNT £ UP OLIM-COUNT 192 WRITE(6, 4) NUMBEPd), M>EEP<2)» NUMEER (I) 4 FORMA T(1X, 'DAY', 15, '/TIME', 15, • - MAG-REACING CF», 15, ' OFF +LIMITS SO WAS SET TO ZERO * * 4 * 4 4 4 * * * * * 4 * * » ) NLMBE R(I ) = 0 VMAG = VMAG-1 CL IM.=0LIM+1 199 CCMIMJE C C44:<4«4*4N0W HAVE NUMBER ARRAY WITH DAY, TIME S VMAO-MACS. IF VMAG = 0, PRINT MSG, C SET AVMAG=G FOR 0/P(ON TAPE) 2CC IF(VM,AG.GT.C) GC TO 202 2G1 A V M A G = 0 WRITE(6,5) NUMB ER(1) , N U M B ER(2) 5 FCRMATdX, 'NC VALIC MAGS AT ALL AT DAY «, 15, ' - TIME ', 15) C VMAG NCT ZERO - SET IP 1 C ATA' ARRAY TC C/P AS A ELCCK. STORE DAY-TIME C -AVMAG CYCLICLY AND WR ITE CN O/P TAPE CNCE 8LCCKSIZE REACHED. C (A)STGRE DAY IN 'DATA' ARRAY 2C2 DATA(OCNT)=NUMBER(1) C ( B ) STORE TIME OCNT=OCNT+l DATA(CCNT)=NUMEER(2) IF(VMAG.GT.C) GO TO 2C4 C VMAG=C SO BYPASS MAG-AVERAGING £ SET AVMAG=0 CCNT=CCNT+1 AVMAG=0 GO TO 209 C (C)STORE AVMAG - CALCILATE AVMAG FIRST(RCUND INTEGER UPWARCS) 204 CCNT=CCNT+1 SUM = 0 DO 207 1=3, WPM SUM=SUM+NUMEEP(I) 2C7 CONTINLE AVMAG=1.*SUM/VMAG+.5 2CS CATA (OCNT )= AVMAG C4*444*4*FCR SFCT-CFECK, PRINT FTAPE FRAMES £ DECODED O/P FOR VISLAL COMPARISCN C EVERY 3C MINS CF CATA(PERIOD SET EY XX IN * MCD(CCNT,XX) WHERE XX IS THE C OCNT PERIOC=(PERIOD IN MINS)*3 (SINCE I MIN. DATA C/F UPS CCNT BY 3) 210 IF(MCD(CCNT,90).EQ.O) WRITE(c,6) OCNT, Q, FRI ME , NLM8ER, AVMAG 6 FCRMATdX, • SPCT-CHECK AT CCNT CF', 14, * C/P BLOCK NO.', 13/ + 1X, 'THE FRI DEN-CODEC FRAMES ARE '/IX, 3CI4/1X, 30I4/1X, 'THE DECO + C EC C/P NUM E E PS ARE '/IX, 12I5/1X, 'COMPUTED AVERAGE MAG-READING = + AVMAG = 5«, 14, ' GAMMAS') C C44444444CHECK IF BLOCKSIZE REACHED - YES? WRITE CN O/P TAPE WITH 15 FORMAT. C ELOCKSIZE MAX. OF 810 CHOSEN AS PER COMMENTS AT START CF PROGRAM. IF(CCNT.LT.EIC) GO TC 1C1 WRITE(3,999) DATA 999 FCPMAT(90(9I5)) C = C+ 1 GO TO 100 C C****4***WHEN END CF PTAPE FOUNC(CALL PTAPE EXIT £11) C WRITE CATA( ) ARRAY ZERCING UNLSEC LCCATICNS. CALCULATE TOTAL O/P C DATA-POINT COUNT(TOCNT) FCR THE PTAPE. 11 KK=CCNT+1 DC 220 I K = K K , 810 DATA ( IK ) = C 22C CCNT INUE WRITE(3,999) CATA TOCNT= (Q-l )*81G+CC,NT M INCT=T0CNT/3 TEMPO=CCNT TEMFC1=TEMPC-1 TEMP02=TEMPC1-1 WRITE(fc,12) PTNQ, PCNT, BLMF, MINCT, Q, OLIM, DATA(TEMPC2 ) , + DATA (TEMPC1 ) , CATA(TEMPC') 12 FCRMA T('G', 4X, 'FINAL STATISTICS FOR PAPER-TAFE NO.", I3/1X,'PTAP + E FRAMES COUNTED = «, 17, ' - NUM8ER I NDECCDEAB LE = *, I5/1X,'NUMB + EP CF MINUTES OF DAT A O/P =', 15, « IN', 13, • BLOCKS CN MAG TAPE' / + 1X, 'NUMBER CF MAG-RE AC INGS CUTSIDE SET LIMITS =•, I4/1X, 'END OF +PTAPE FOUND AT DAY', 14, ', TIME', 15, *, AVMAG 5', 14, • GAMMAS'/ + /1X, ' ******* 444**** 4**4**4 4 4 44 4 4 4**444**4**:*** 44*44*44***44****** + 4444* ******* 4 44*444<5!>i=! 44 ***•/) r WRITE END-CF-FILE CN C/F MAGTAPE £ CHARGE CN TC NEXT PAPERTAPE ENCFILE 3 PTNC=PTNC-U C GCTC 5CC INSTEAD IF E> IT AFTER 1 PTAPE WANTED. FORMAT STMT 999 O.K.? GO TO 99 C C**4*****WHEN E NC CF ALL FT APES FCUNCJCALL PTAPE EXIT 621) C REPEAT STEPS AS S. 11 EXIT BLT EXTRA URI TE MSG £ EXTRA ENCFILE 21 KK=OCNT-H CC 221 IK=KKt 810 OA TA( IK)=C 221 CONTINUE WRITE(3,999) C AT A TCCNT=(Q-l)*810+CCNT M INCT = TOCNT/3 TEMPO = CCM TEMP01=TEMPC-1 TEMP02=TEMPC1-1 WRITE(6,12) PTNO, PCNT, BLMF, MINCT, Q, OLIM, DATA{TEMPC2 ) , +DATA(TEMP01), CATA(TEMPO) WRITE(6,22) 22 FORMAT( IX, 'THATS ALL THE PAPER TAPES * * * * * * * * * 4 4 * * * 4 * * * 4 4 4 4 « * * * » ) C WRITE TWC ENDFILES ON C/F MAGTAPE AND QUIT ENDFILE 3 ENCFILE 3 GO TO 5CG C C4444****BCIVB CUT CPTION ACC WRITE(6,31) PTNC 31 FORMAT(IX, '4*44* BOMB OUT ***** SEPARATORS GOCFED EVEN AFTER FIRS +T 6CC PTAPE FRAMES READ. CHECK INPUT CATA. PTAPE NO. = ', 13) 5CO STOP EN C $ C C F V * S K I P * S I N K * $CCPY *SGURCE*a^CC *S INK*3-.CC C ****** DECCA NAVIGATION PROGRAM *DECNAV* ****** C C DAY/TIME/OECCA CO-ORDS OF AN OBSERVER ARE READ IN ANO C DAY/TIME/SECUENTIAL MINUTES/GEOGRAPHIC CO-ORDS ARE COMPUTED. C DECCA CO-ORDS INPUT ARE FOR START/END OF A LINE - THE TYPE OF LINE(STRAIGHT C OR HYPERBOLIC) AND THE DECCA CHAINI6F OR MINIFIX) USED ARE I/P : THE PROG C WILL I NT ERPOL AT E(STRAIGFT OR HYPERBOLIC) ACCORDINGLY, AND USE THE APPROPRIATE C CHAIN PARAMETERS. C-.BEFORE COMPILING/EXECUTING, SET UP DECCA CHAIN PARAMETERS £ OPTION LIST. C LCNT,MCNT=COUNTS TO PRINT CHAIN PARAMETERS ONCE ONLY. C*** LOGICAL UNIT 6 = LINE PRINTER, 5 = CECCA CQ-GRD DATA(PRECEDED B Y FORMAT) C 4 = PROGRAM C/PIUSUALLY COMPUTER TAPE). C 8 = DEBUGGING £ MINOR ERROR MSG O/P - SET=*DUNMY* TC KILL. IMPLICIT RE AL *8 ( A-H,O-Z ) INTEGER** DAY, TIME DIMENSION LINE! 2), FMTH20), FMT2(2C), DAY ( 1000 ) t TIHE(IGOO), P ATT +111000), PATT2(1000), MINUET (1000) f GN(IGCO), GE(IOCO), DLAT(IOOO) + , DLONUOCC), DIST(IOOO), FIXX(IGCO), FIXY(IOOO), OMIN(ICOO), BDIS + TI1000),1YAD( 1000),EMIT!1CCC) ,GEOGX( 10001,GEOGY(1000) DATA H/'H'/fQ/'L'/iP/'M'/.S/'S'/ COMMON FIXIN, H, Q, P, S, LCNT, MCNT C....OPTION LIST. PLEASE SET UP ACCORDING TO REQUIREMENTS. C FIXIN IS FIX INTERVAL IN DECCA LANES - FIXES WILL BE COMPUTED EVERY C FIXIN LANES FOR INTERPOLATION (IF HYPERBOLIC). C ZMINT=TIME INTERVALUN MINS) BETWEEN FINAL 0/ P FIXES COMPUTED. C ZMINT=2.0 C SET IDTM=0 IF DAY/TIME/M INUET/POSITIONS O/P WANTED. C IDTM=1 IF DAY/TIME/PCSITIONS O/P WANTED. C IDTM=2 IF MINUET/PGSITICNS C/P W ANTE C. C SET UTM GRID CONSTANTS AT STMT 1000. C FIXIN=1.0 SET UP AFTER STATEMENT M9C, IDTM=0 ZM INT = 2.0 C READ IN FORMAT BEING USED FOR DECCA CO-ORD I/P. READ(5,50) ( F M T K I ) , 1 = 1,20) 50 FORMAT(2GAA) C FOR MACBAY, (IX,I 5 ,IX,Ik, IX,I 4,IX,F7.3,1X,F7.3,IX,Al,1X,Al ,1X,A3) C SET UP COUNTS. RESET NOT NEEDED - PRINT ONCE ONLY PER PROGRAM EXECUTION. 80 LCNT=1 MCNT=1 C READ IN LINE I.D./OAY/TIME/CECCA CO-ORDS/SELECTIONS. C SELECTIONS: CHAIN = M FCR MINIFIX CHAIN. C CHAIN = S FOP 6F CHAIN(BOTH CHAINS ARE DECCA SYSTEMS). C TRACK = H IF SHIP'S TRACK IS HYPERBOLIC. C TRACK = L IF SHIP'S TRACK IS A 'STRAIGHT' LINE. C LINE CODE=l:START OF LINE (E.G. 10011 FCR START OF LINE 11) C =9:END OF LINE (E.G. 9C011 FOR END OF LINE 11). C =99999 IF LAST CARD. 90 1 = 1 FIXIN=1.0 101 READ! 5, FMT1, ERR = 8000, END=9000 ) LINE (1) ,DAY( I) , T I ME ( I ) , PATH ( I ) , PAT + T2(I) ,CHAIN ,TRACK,PTNC C CHECK IF LAST CARD, IF(LINE(1).NE.99999) GO TO 120 WRITE(6,110 ) 110 FORMAT( IX , * NORMAL JOB TERMINATION') STOP 1 C CHECK IF CARD IS FOR START OF LINE. 120 LCHK=LINE (1 )/l0000 IFtLCHK.EQ.l) GO TO 125 C CARD IS NOT FOR START OF LINE. PRINT MSG S READ NEXT CARD. WRITE(6,126) 126 FORMAT(IX, 'THIS IS NCT CARD FOR START CF LINE. •) WR ITE(6,8050 ) WRITE(6,FMT1) L INE(1 ),DAY( I ) ,TIME(I ),PATT 1 (I),PATT2(I ),CHAIN .TRACK +,PTNO GO TO 90 125 CALL MINTY ( DAY ( I ),T IME ( I ),M INUET ( I ) ) C PRINT 127, I , DAY(I), TIME(I), MINUET(I) C 127 FORMAT ( IX, 'FOR I=',I5,' DA Y/T IME /Ml NUE T = ' , 3(IX,I7)) C READ IN NEXT CARD AN C CHECK IF FOR END OF SAME LINE. READ AGAIN IF NOT. 130 J=1000 READ(5»FMT1,ERR=808Q,END=9000) LINE(2 ) , DAY(J) ,TIME (J ) , P A T T l ( J ) , P + ATT2U), CHAIN, TRACK, PTNO LDIFF = IABS(LINE(2)-L INE(l) ) IF(LDIFF.NE.8C0O0) GO TC 146 CALL MI NT Y(DAY(J),TIME(J),MINUE T ( J ) ) C PRINT 136, J , DAY(J), TIME(J), MINUET(J) C 136 FORMATdX,'FOR J=',I5,« DAY/T I ME/MI NUET= ' , 3(1X,I7)) GO TO 160 146 WRITE(6,150) 150 FORM AT (IX, '*** ERROR ... STA RT/END CARC-PAIR *10T FOUND. CARDS ARE') WR I TE ( 6 » FMT1 ) LINE(1 ) ,DAY{I> ,TI ME( I),PATT 1 ( I) , PATT2 ( 1 ), CHAIN ,TRACK +, PTNO WRITE(6,FMT1 ) LINE(2),DAY(J ) ,TIME(J),PAT T 1 (J),PATT2(J),CHAIN , TRACK +,PTNO 153 GO TO 9C C HAVE START/END CARDS FOR SAME LINE. CHECK WHAT INTERPOLATION NEEDED. C 'H» FOR HYPERBOLIC : «L« FOR STRAIGHT LINE. 160 WRITE(6,162) 162 FORMAT ( IX, 'START £, END OF LINE BEING PROCESSED ...') WRITE(6,8050) WRITE(6,FMT1) L INE (1 ) , D A Y (I ) , T IME ( I ) , P ATT 1 ( I),PATT2(I),CHA IN,TRACK +,PTNO WR ITE( 6, FMT1 ) L INE ( 2 ) ,DA Y( J) ,T I ME ( J ) , PATT1 ( J) ,PATT2 ( J) ,CHA IN ,TRACK + ,PTNO IF(TRACK.EC.H) GO TO 170 IF(TRACK.EQ.Q) GO TC 7CC C TRACK TYPE UNSPECIFIED. ERROR. WRITE(6,165) 165 FORMATdX, 'TRACK TYPE UNSPECIFIED FOR THIS LINE....') WRITE(6,8050) WRITE(6,FMT1) L INE(1 ),DAY (I ) ,T IME(I ),PATT1(I) fPATT2(I),CHAIN,TRACK +,PTNO WRITE(6 tFMT1) LINE(2),DAY(J),TI ME(J),PATT1 ( J) ,PATT2{J),CHAIN,TRACK +,PTNO GO TO 90 C*****HYPERBOLIC INTERPOLATION NEEDED. C HAVE DECCA CO-ORDS FOR START/END CF LINE. DETERMINE WHICH IS TRACK LANE. 170 IF (P ATT l ( I ) . E Q . P A T T K J ) ) GO TO 210 IF(PATT2(I).EC.PATT2(J)) GO TO 280 C SOMETHING WRONG. NO TRACK LANE FOUND. PRINT MSG S READ NEXT CARD. WRITE(6,19C) L INE ( I ) 190 FORMAT(IX, 'NO TRACK LANE FOUND FOR LINE ',15,' **************') GO TO 90 C PATTERN I (RED) IS OUR TRACK LANE. GET LCWER PATTERN 2 READING SO W£ C KNOW IF FIX IN IS POSITIVE OR NEGATIVE. 210 IF(PATT2(I).LT.PATT2(J)) GC TO 222 C PATT2U) IS LOWER READING. SET FIXIN NEGATIVE- FIX IN=-FIX IN C..... COMPUTE POSITIONS WITH SBRTN DECCA FROM PATT2U) TO PATT2U) EVERY C FIXIN LANES. REMEMBER PATT 1 IS CONSTANT. SO USE P ATT 1(1) ONLY. 2 22 CALL DECCA(LIM E ( 1) ,P A TT H 1),PATT2(I ) ,GN(I) ,GE(I),DLAT(I),DLON( I) ,C +HAIN,£90,£9999) C PRINT 223, I, J C 223 FORMAT (IX, 'AT 222, VALUE OF I IS', 17, ' - J IS «, 17) 1=1 + 1 K = I-1 PATT2U )=PATT2( K)+FI XI N C MAKE SURE LAST POSIT I ONtPATT2 (J ) ) IS COMPUTED. IF(PATT2(I).LE.PATT2(J) ) GO TO 222 C.....IF EQUAL TO, LAST POSITICNtFCR PAIT2(J)) ALREADY CONE - SO EXIT. IF(PATT2(K).EQ.PATT2(J) ) GO TO 300 C NOT EQUAL,MUST BE GREATER. SO COMPUTE FOR PATTERN2(J ) AFORE EXIT. PATT2U ) =PATT2 ( J) CALL DECCA(LINE(1),PATTI(1),PATT2(I),GN(I),GE(I),DLAT(I),DLON(I),C +HAIN,£90,£9999) GO TO 3C2 C PATTERN 2 (GREEN) IS TRACK LANE. REPEAT AS STMTS 210-22C BUT PATT2 CONST. 280 I F( PATT 1(1) .LT .P ATT1 (J ) ) GO TO 292 FIXIN=-FIXIN 29 2 CALL DECCA(LINE(1),PATT1(I),PATT2(1),GN(I),GE(I),DLAT(I),DLON(I),C +HAIN,£90,£9999) C PRINT 2 93 , I , J C 293 FORMAT( IX, 'AT 292 VALUE OF I IS ', 17, • - J IS ' t 17) 1=1+1 K = I-1 PATT1 (I )=PATT1(K)+FIXIN IF (PATT 1(1 ) .LE.PATTKJ ) ) GO TO 2 92 I F ( PATT 1 ( K ) .EQ.P ATT 1 (J ) ) GO TO 300 PATT1 (I ) = PATT1 ( J) CALL DECCA(LINE(1),PATT 1(I) , PATT2(1),GN(I),GE(I ) ,DLAT(I),DLON(I),C +HAIN,£90,£9999) GO TO 3 02 C FIXES ALL COMPUTED. GET DISTANCE BETWEEN FIXES £ TOTAL LINE LENGTH. C.....TDIST=TOTAL LENGTH OF LINE. C THIS IS THE * K * EXIT - VALUE OF »I' TOO HIGH BY 1. 300 1=1-1 C THIS IS THE >I' EXIT. VALUE OF 'I • O.K. STORE IT(IT IS MAX. HERE). 3 02 t = I C PRINT 303, L C 3G3 FORMAT(IX, 'AT 302, L IS *, 16) TDIST=0 DO 350 M=2,L N = M-1 CALL DlSTAN(DLA T(M),DLON(M),DLAT(N),CLON(N),D I ST(N ) ) C PRINT 340, M,N,DLATIM),DLON(M),DLAT (N),DLON(N),DI ST(N) C 340 FORMAT ( IX , * FOR M/N=•,2(IX,I 3),' DL AT ( M ) / DL OiM( M ) , DL AT ( N ) / DLON (N ) / D I C +ST(N) ARE »,5( 1X,F10.3)) C PRINT 343, N, DIST(N), TDIST C 343 FORMAT!IX,'FOR M=',I3,' DIST(N)«,F10.3,• ADDS UP TO TDIST 0F«,F10. C +3) 350 TDIST=TDIST+DIST(N) C NOW HAVE ARRAY OF FIXES £ DISTANCES BETWEEN THEM. COMPUTE SHIP'S SPEED. ELAPSE=DFLCAT(MINUET(J)-MINUET(1)) C P R I N T 3 6 0 , E L A P S E , M I N U E T ( J ) , M I N U E T l l ) C 3 6 0 F O R M A T ( I X , • ELAPSE= ' , F 6 . 1 , • - SHOULD B E ' , 1 6 , " MINUS ' , 1 6 ) S P E E D = ( T D I S T / E L A P S E ) * 6 0 . W R I T E ( 6 , 3 8 G ) L I N E ( 1 ) , T D 1 S T , E L A P S E , S P E E D 3 8 0 F O R M A T ( I X , 'CHECK : L I N E ' , 1 5 , ' - S A I L E D ' , F 8 . 3 , ' NC I N « , F 8 . 3 , ' M + I N S - SPEED = ' , F 8 . 3 , ' K N O T S ' ) C SET M I N U T E S - B E T W E E N - F I X E S - I N T E R V A L R E Q U I R E D . C 1 M I N U T E A P P R O X . EQUAL TO 1 6 0 0 FEET AT 16 K N O T S . C 4 5 0 Z M I N T = 2 . 0 C D I V I D E S T A R T / E N D T IMES CF L I N E BY ZMINT TO GET ' Z F I X ' , THE N O . OF F I X E S C FOR L I N E . D I V I D E L I N E LENGTH • T D I ST• EY Z F I X TO GET D I S T A N C E I N T E R V A L C BETWEEN F I X E S ' F D I N T ' . Z F I X = E L A P S E / Z M I N T F D I N T = T D I S T / Z F I X C GET INT E G E R ( Z F I X ) , ADD 1 - T H I S I S NO. OF F I X E S WE END UP WITH FOR L I N E N F I X = ( I C I N T ( Z F I X ) ) + l C P R I N T 4 6 0 , Z M I N T , Z F I X , F C I N T , E L A P S E , L I N E ( 1 ) C 4 6 0 F O R M A T ! I X , ' E V E R Y ' , F 5 . 2 , ' M I N G I V E S » , F 7 , 2 , • F I X E S * , F 7 . 2 , ' D I S T APART C + O V E R • , F 8 . 3 , ' M I N FOR L I N E # ' , I 6 ) C * * * * * I N T E R P O L A T I O N L O O P . USE N F I X AS LOOP C O N T R O L L E R . C F D I S T = C U M U L A T I V E D I S T A N C E TWEEN F I N A L O / P F I X E S ( F D I NT M I N S . A P A R T ) . C CD IST=CUMUL A T I V E D ISTANCE TWEEN DECCA P O I N T S COMPUTED A B O V E . C C A U T I O N : D D I S T SHOULD ADC UP TO T D 1 S T ( L I N E L E N G T H ) BUT NEVER Q U I T E D O E S . 4 7 5 D D I S T = 0 F C I S T = 0 C SET UP F I R S T O / P F I X , 4 8 0 F I X X ( 1 ) = G N ( 1 ) F I X Y ( 1 ) = G E ( 1 ) O M I N d ) = D F L O A T ( M I N U E T ( 1 ) ) C P R I N T 4 8 3 , O M I N l 1 ) , F IXX ( 1 ) , F I X Y ( 1 ) C 4 8 3 FORMAT! I X , 1 F I R S T O / P F I X SET U P . CM I N { 1 ) / F I X X ( 1 ) / F I X Y ( 1 ) A R E ' , 3 ( 1 C + X , F 1 0 . 3 ) ) C NOW GET OTHER F I X E S WHICH NEED I N T E R P O L A T I O N THOUGH. F I X TO BE COMPUTED C MUST ALWAYS BE D E F I N E D BY P O I N T S ! J ) £ P O I N T S ! I ) . C J = 2 , N F I X - I = J - 1 N F I X = N O . OF O/P F I X E S . C M = 1 , N - L = M - 1 N = N O . OF P O I N T S CO-ORDS KNOWN(DECCA COMPUT. ABOVE) M = l 5 0 0 DO 6 0 0 J = 2 , N F I X I = J - 1 F D I S T = F D I S T + F D I N T C P R I N T 5 C 5 , J , F D I S T , F D I N T C 5 0 5 F O R M A T ( I X , ' F O R J = ' , I 3 , ' F D I S T / F D I NT ARE• , 2 ( I X , F 8 . 3 ) ) C CHECK I F F I X D E F I N E D BY DECCA P O I N T S I N HAND. 5 1 0 I F ( F O I S T . G T . D D I S T ) GO TC 5 2 5 C . • • • • D E F I N E D - GET ' D I F F * £ GO TO I N T E R P O L A T I N G S T A T E M E N T S . D I F F = C D I S T - F D I S T GC TO 5 5 0 C . . . . . N O T D E F I N E D . UP M £ GET NEW D D I S T . RECHECK D E F I N I T I O N BY NEW P O I N T S . C 5 2 5 P R I N T 5 2 9 , J , D D I S T , F D I ST C 5 2 9 F C R M A T t l X , ' A T 5 2 5 , FCR J = ' , I 3 , ' D D I S T / F D I S T A R E • , 2 ! I X , F £ . 3 ) ) 5 2 5 M=M+1 L = M - 1 D D I S T = D D I S T + C I S T ( L ) C P R I N T 5 3 3 , M , L , D D I S T , C I S T ( L ) C 5 3 3 FORMAT ( IX , ' A T 5 2 5 + , M/L A R E ' , 2 ( 1 X , 1 3 ) , ' C C I ST / 0 1ST I L ) A R E ' , 2 ( 1 X , F 8 C + . 3 ) ) GG TO 5 1 0 C I N T E R P O L A T I N G S T M T S . F I X D E F I N E D EY PCINTS(M) £ P O I N T S ( L ) . 5 50 F I X X ( J ) = G N ( M ) - ( ( ( S N ( M ) - G N ( L ) ) * D I F F ) / D I S T ( L ) ) F I X Y ( J ) = G E ( M ) - ( ( (GE (M ) - G E (L ) )*D I F F ) / D I S T (L ) ) OMIN< J)=0MIN(D + ZMINT C PRINT 571, J,M,L C 571 FORMAT(IX,•FOR J/M/L OF',3(IX,15), * WE HAVE ..') C PRINT 573 , FIXX(J),OLAT(M),CLAT(L),CIST<L) C 573 FORMAT(lX,*FIXX(J),OLAT(M),OLAT(L),DISTIL) ARE 1,4(IX,F 10.3)) C PRINT 577, DIFF, J C 577 FORMAT.IX,•DIFF ISVF10.3,* FOR J OF',13) C PRINT 579, OMIN(J),OMIN(I) ,ZMINT,I C 579 FORMAT(IX, 'OM IN ( J ) /OMIN( I)/ZMIN T ARE» ,3( IX ,F10.1),» FOR 1=' ,16) 600 CCNTINUE C.....ALL INTERPOLATIONS DONE - GC TO O/P AREA. GO TO 1CG0 C*****STRAIGHT TRACK LINE. WE HAVE START/END - SO ZONVERT TO GEOG-POSNS FIRST. 700 CALL DECCA(L INE<1),PATT1(I),PATT2(I),GN<I),GE(I ) ,DLAT(I ) ,DLON(I),C +HAIN,£9C,S9999) CALL DECCA(LINE(2),PATT1(J) ,PATT2{J),GN(J) ,GE(J),DLAT(J),DLON(J ) ,C +HAIN,&90,£9999) C NOW HAVE 2 GEOG POSNS. CCMPUTE SHIP'S SPEED. CALL D I STAN! DLA T( J ) ,DLON ( J) »DLA T ( I ) »DL ON (I) ,DISTM) ) TDIST=DIST t l ) ELAPSE=DFLOAT(MINUET(J)-MINLET(1)) SPEEO=(TDIST/EL APSE)*60. WRITE(6,380 ) 'LINE(1),TD 1ST,ELAPSE,SPEED C FROM 2 GEOG PCSNS £ ZMINT (STMT 450) GET NC. OF FIXES NEEDED FOR LINE. ZFIX=ELAPSE/ZMINT NFIX=( I DINT(ZFIX)) + l C GET DIFFERENCES IN LAT/LCN BETWEEN POSNS. DIFGN=GN(J)-GN(I) DIFGE=GE( J )-GE( I ) C COMPUTE GN/GE INCREMENTS BETWEEN INTERPOLATIONS - CALLED UPGN/UPGE. UPGN=DIFGN/ZFIX UPGE=DIFGE/ZFIX C NOW INTERPOLATE. REMEMBER NF IX=( INTEGER PART(ZFIX)) + 1=N0.OF FIXES. C INITIALISE FIXX, FIXY, CMIN. FIXX(1)=GN(1) FIXY( 1)=GE(1 ) GM I N( 1 )= DFLO AT (M INUET (1 ) ) DO 800 IM=2,NFIX IN= IM-1 FIXXl IM )=FIXX ( IN )+UPGN FIXY(IM)=FIXY(IN)+UPGE OMIN(IM)=OMIN(INJ+ZMINT 800 CONTINUE C HAVE ALL FIXES. GO TO O/P AREA. GO TO 1C00 C****« O/P AREA C ALL FIXES IN UTM CO-ORDS DONE. CONVERT TO GEOG CO-ORDS, THEN O/P C ACCORDING TO TYPE OF 'TIME' O/P DESIRED. NOTE NFIX=NO. OF FIXES. C SF=SCALE FACTOR; DR=DEGREE-RADlAN CCNVERSION FACTCR; C ORE= FALSE EASTIMG; 0*N=FALSE NORTHING; I ZCN6=UTM ZONE. 1000 SF=0.99960 DR=0.01745329252 ORE=5CCC0O. ORN=0 . IZCNE=8 GL=IZ0NE*6. GL=183.-GL DC 1002 K=1,NFIX CALL B51211(AA2,B2,FIXY(K),FIXX(K),SF,ORE,ORN) GE0GX(K)=AA2/DR 1002 GEOGY(K)=(B2/DR)+GL IF(IDTM.EQ.2) GO TO 1010 IF{IDTM.EQ. 1) GO TO 1C2C IF( IDTM.EQ.O ) GO TO 1020 WRITE(6,1004) 1004 FORMAT I IX» * FATAL ERROR - TYPE CF TIME C/P WANT ED UNRECOGNISED') STOP 8 C.....MINUTE-ONLY O/P WANTED. NO MORE COMPUTATIONS NEEDED. 1010 WRIT£(4,1012) L I N E ( l ) , NFIX 1012 FORMAT(16, IX,16) WRITE!4,1013) (OMIN(I )» FI XX(I) ,FIXY(I),GEOGX{I) ,GEOGYII ) ,1 = 1,NFIX) 1013 F0RMAT(F10.2,1X,F15.3,1X,F15.3,1X,F15.8,IX,F15.8 ) GO TO 1050 C....DAY/TIME WANTED. CONVERT MINUET BACK. 1020 DO 1024 1=1,NFIX CALL UNMINT(CM IN(I)» IY A C ( I) ,EMIT{ I ) ) 1024 CONTINUE C NOW O/P ACCORDING TO IDTM CHOSEN. IF (IDTM.EQ. I) GO TO 1028 C.....IDTM=0 - DAY/TIME/MINUET O/P WANTED. WRITE (4, 1026) L I N E ( l ) , NFIX 1026 FORMAT(16 ,1X , 16) WRITE(4, 10 27) (IYAD(I),EMIT( I) , CM IN(I),FI XX (I ) ,F IXY (I),G EOGX(I),GE +OGY(I), 1=1, NFIX) 1027 FCR MAT ( 15 , IX, F7 .2 , IX , F10 .2 , IX,F 15 . 3, IX, F 15. 3, 1X , F 15 . 8 , 1 X , F l 5 . 8 ) GO TG 1050 C IDTM=1 - DAY/TIME ONLY O/P WANTED. 1028 WRITE(4, 1029) L I N E ( l ) , NFIX 1029 FORMAT(16,IX,16) WRITE(4,103 0) ( IYADlI),E MIT(I),FI X X(I),FIXY{I),GEOGX(I ),GEOGY(I), + 1=1,NFIX ) 1030 FOR MAT ( 15 , IX ,F7 .2 , IX , F15 . 3 , IX,F 15 . 3, IX, F 15. 8, IX, F15 .8 ) C.....O/P WRITTEN. SIGNAL THIS. WRITE ENCFILE ALSO. 1050 WRITE(6,1053) NFIX,LIN£(1) 1053 FORMAT(IX,15,• FIXES O/P ON UNIT 4 - LINE',I6 T> PROCESSED•/) END FILE 4 GO TO 90 C READ ERROR. TRY AGAIN. TERMINATE ONLY OF ENDFILE OR *99<;99-LAST CARD 8000 WRITE(6 ,8010) 801C FORMA T ( IX, ****** READ ERRCR ON FCLLCWING .... ') WRITE(6,8050) 8050 FORMAT(2X, 'LINE DAY TIME PATT1 PATT2 C T PT**) WRITE(6,FMT1) LINE(I) ,DAY(I) ,TI ME( I),PATT1(I),PATT2(I ),CFA IH , TRACK +,PTNO GC TC 90 8080 WRITE(6,8010) WRITE(6,8050) WRITE(6,FMT1) L INE ( 2 ) , DA Y( J ) , TI ME (J ) , PATTK J) ,PATT2 (J) ,CHA1N,TRACK +,PTNO GO TO 90 C***** ENDFILE ENCOUNTERED. BOMB OUT. 9000 WRITE(6,9010) 9010 FORMAT(IX, ENDFILE ENCOUNTERED. ERRCR OR LAST CARC NOT "9999 +9 • " ) STOP 9 C*****NAV SYSTEM UNSPECIFIED. BOMB OUT. 9999 STOP 3 END C******************************^**^^^^*^^^^^^^^^************************** SUBROUTINE DECCA(MFIX,Rl,R2,GN,GE,DLAT,DLCN,CHA IN,*,* ) C**=* DECCA NAVIGATION! PROGRAM - COURTESY MARINE SCIENCES VICTORIA *** C.DECCA RECEIVES THE DECCA CO-ORCINATES OF AN OBSERVER & COMPUTES HIS/HER C POSITION FIRST IN UTM £ THEN IN GEOGRAPHIC CO-ORDINATES. C..TWO DECCA SYSTEMS WERE USEE IN THE MACBAY AREA(CALLED THE 6F £ THE MINIFIX C SYSTEMS) - SO DECCA DETERMINES WHICH IS BEING USED BEFORE COMPUTATIONS C COMMENCE. C A L L CO-ORDINATES ARE ASSUMED BY DECCA TC BE IN THE SAME UTM ZONE. C C....LINE=I.D. OF LINE OR POINT BEING PROCESSED. C R1/R2=PATTERN 1 £ PATTERN 2 DECCA CO-ORDINATES CF OBSERVER. C DLAT/DLON=LAT £ LCN CF OBSERVER RETURNED BY DECCA. DEGREES ONLY{E.G. 49.51 C***** SET UP PARAMETERS FIRST. UTM-ZONE, CHAIN PARS £ SCALE FACTOR FOR AREA. C IMPLICIT REAL*8 (A-H, C-Z ) COMMON FIXIN, H, Q, P, S, LCNT, MCNT C DATA P/»M'/,S/»S'/ C . . . SET UP PRINT COUNTS. LCNT FOR 6F, MCNT FOR MINIFIX. C MCNT=1 C LCNT=1 C 109 RE AD(5,110,END=880) MFIX,R1,R2,CHAIN C 110 FORMAT(1X»I5»1X,F7.2»1X»F7.2»1X,A1) C.....SET UTM-ZONE. IZCNE=8 C SET SCALE FACTOR, USUALLY MEAN SCALE FACTOR FOR WHOLE AREA. SF=0.9996 C SET CHAIN PARAMETERS. C V=SPEED OF PROPAGATION CF E.M. WAVES IM KM/SEC. C Q1=FREQUENCY FOR SLAVE 1 IN KHZ. C Q2=FREQUENCY FOR SLAVE 2 IN KHZ. C IF SYSTEM IS SINGLE FREQUENCY, MAKE Q2=Q1 C XM,YM = EASTING AND NORTHING CF MASTER STATION C XS1, YS1=EASTING AND NORTHING OF SLAVE 1 C XS2,YS2=EASTING AND NORTHING OF SLAVE 2 C.....SKIP 6F CHAIN PARS IF MINIFIX IS SYSTEM BEING USED. IF(CHAIN.EQ.P) GO TO 312 IF(CHAIN.NE.S) GO TO 900 C 6F SYSTEMS PARAMETERS ARE: 308 V=299650.0 Ql=355. 92 02=266.94 YM=7731381.78 XM=502649.21 YS1=7762342.307 XS1=636554.457 YS2=7722501.814 XS2=347563.076 C . . . CHAIN PARAMETERS COMING UP - PRINT WHICH CHAIN FIRST. C WRITE(6,310) CR WRITE(6,311) 310 F0RMAT(/1X, * FOR DECCA 6F SYSTEM') 311 F0RMAT(/1X, 'FOR DECCA MINIFIX SYSTEM') C CHAIN PARAMETERS FORMAT. C WRITE(6,321) I ZONE , SF , V , YM , XM , Y SI ,XS 1, YS 2 ,X S2 321 FORMAT( IX, 'CHAIN PARAMETERS INPUT ARE ....'/IX, 'AREA-WIDE : UTM- + ZCNE *, 13, ' £ SCALE-FACTOR *,F9.7/1X, 'VELOCITY OF PROPAGATION AS + SUMED IS ' ,F10.2,' KM/SEC'/IX,' MASTER CC-ORDS IN UTM = NORTHING ' +,F12.3, • - EASTING •,F12.3/1X,•SLAVE 1 CO-ORDS IN UTM = NORTHING » + ,F12.3,' - EASTING *»F12.3/1X, 'SLAVE 2 CO-ORDS IN UTM = NORTHING • +,F12.3,« - EASTING «,F12.3/) C PRINT CHAIN HEADING £ PARAMETERS ONCE - DISPLAY ONLY IF(LCNT .GT.1 ) GO TO 120 WRITE(6,310) WRITE(6,321) IZ0NE,SF,V,YM,XM,YS1,XS1,YS2,XS2 LCNT=LCNT +1 C SKIP OVER OTHER CHAIN NCW. GO TO 120 C......SET UP M IM IF IX SYSTEM PARAMETERS NOW. MACBAY SLAVE 1/SLAVE 2 REVERSED. 312 V=299650.0 Ql=1702. Q2=1702. YS1=7664CG7.32 XS1=455153.98 YM=7656233. 87 XM=400817. 93 YS2=7687375.22 XS2=368354.65 C PRINT CHAIN HEADING & PARAMETERS ONCE FOR OISPLAY. IF(MCNT.GT.l) GO TO 120 WRITE (6,311) WRITE(6,321) IZ0NE,SF,V,YM,XM,YS1 ,XS1,YS2,XS2 MCNT = MCNT +1 r C COMPUTE BASELINES 120 A1=DSQRT((XM-XS1)**2 +(YM-YS1)**2) A2= DSQRT( (XVJ-XS2 )**2+( YM-YS2)**2) X1=XS1-XM X2=XS2-XM Y1=YS1-YM Y2=YS2-YM AK=X1*Y2-Y1*X2 ZQ=(Al*#2*Y2-A2*#2*Yl)/2«/AK ZT=(A2**2*Xl-Al**2*X2)/2./AK V1=V*SF 9C AK1 = 1.-((R1*V1)/(Q1*A1) ) AK2=1.-((R2*V1)/(Q2*A2) ) ZP=((A2*Yl*AK2)-(A1*Y2*AK1))/AK ZS=((A1*X2*AK1)-(A2*X1*AK2))/AK ZR=( (Al**2*Y2*AKl**2)-(A2**2*Y1*AK2**2 ) ) / 2./AK ZV=((A2**2*X1*AK2**2)-( A 1**2*X2*AK1**2)) /2./AK B1=ZT-ZV B2=ZQ-ZR B3=ZP**2+ZS**2-1 . B4=ZP*B2 B5=ZS*B1 B6=B4+B5 B7=B6**2 B8=B3*IB2**2+B1**2) IF(B7)2C,2C,3G 30 RACIC=B7-B8 IF(RADIC)40,40,50 5C D=(-B6-DSQRT(RADIC))/B3 IF(D)60,6C,7C oQ D= ( -B6 + CSGRT (RADIC ) )/B3 IF(D)80,80,70 70 X=ZP*D+B2+XM Y=ZS*D+B1+YM GN=Y GE=X GO TO 1C00 20 WRITE(6,12) MFIX, R l , R2 12 FORMAKIX,'SOLUTION INVALID. NO FIX FCR LINE «,I7, 'WHICH IS PATT1 + ', F8.3, ' - PA TT 2 *, F 8.3) RETURN 1 ; STOP 40 WRITE(6,13) MFIX, R l , R2 13 FORMAT! IX,'SOLUTION I MAGIN. NO FIX FOR LINE «,I7, 'WHICH IS PATT 1 + «, F8.3, ' - PATT2 ', F8.3) RETURN 1 C STOP 30 WRITE(6,12) MFIX, R l , R2 RETURN 1 C STOP 1C00 SCFACT=SF DR=0. 01745329252 ORE = 5C0C0C. ORN=0. GL=IZ0NE*6 GL=183.-GL C CONVERSION FROM GRID TC GEOGRAPHIC C CALL B51211(AA2,E2,GE,GN,SCFACT,0RE,0RN) C AL2=AA2/DR IAL2=AL2 XMIN=(AL2-IAL2)*60 MIN = XMI N ASEC=(XMIN-^IM)*60 ALC2=82/DR + GL IAL02=ALC2 XMIN=(AL02-IAL02)*60 IMIN=XMIN BSEC=(XMIN-IHIN).*60 C84 WRITE (6,22)MFIX,R1 ,R2 ,GN,GE ,IAL2 ,MI N, ASECIALC2, IMIN, ESEC, I ZONE C2 2 FORMAT( •0•,2X,I 5,5X,F8.3,3X,F8.3,3X,F11.3,F12.3,4X,21 3,F6.2 , 6X, C 52I3,F6.2,5X, 12 ) C C....CONVERT DEG/MINS/SEC TO CEGREES-CNLY. DLAT=IAL2+IMIN/60.)+ (ASEC/3600. ) DLCN=IAL02+{IMIN/60.) + (eSEC/3600 . ) C WRITE(6,86) MFIX,DLAT,OLCN C 86 FORMAT (IX, 15, 2X, F1C.4, 2X, F10.4) C GC TC 109 C 880 STCP 8 RETURN C....ERROR EXIT. NAV SYSTEM UNSPECIFIED. 900 WRITE(6,90U 901 FORMAT(2X,'*** ERROR - NAV SYSTEM NEITHER MINIFIX NOR 6F 44*') C STOP 9 RETURN 2 END SUBROUTINE B51211 (DA,DC,GE,GN,SCFACT,ORE,CRN) IMPLICIT REAL*8(A-H,0-Z) C GRID TO GEOGR. ANY SPHEROID PROGRAM B51211 (P2C3) C C C ** INPUT, C C GE = EASTING C GN = NORTHING C SCFACT = CENTRAL SCALE FACTOR C ORE = FALSE EASTING C ORN = FALSE NORTHING C C C **OUTPUT, C C DA = LATTITUDE, NOR TH{ + ), SOUTH(-) C DO = C IFF. OF LONGITUDE, ( + ) FOR POINT WEST OF MERIDIAN C C A1=63782C6.4 P2=0.67686579973D-2 DE LT = 0.68147849459D-2 C C Al = EQUATORIAL SEMI-AXIS C P2 = EXCENTRICITY SQUARED C DELT = P2/(2.-P2) C X= -(GE-ORE)/SCFACT YY= (GN-ORN)/SCFACT Y=DABSCYY) C1=.75*P2 C2=C1*P2*,9375 C3=C2*P2*.9722222222 C4=C3*P2*.984375 C5=A1*{1.-P2) P3=P2*.5 P4=l.-P3 P5=DSGRT(P4) P6=P4*P5 PZ=P4*P4 PX=P6*P4 PY=P2*P2 P7= l . / ( l . - P 2 ) P8 = P7*P7 P9=P8*P7 YA=(Y—4984727.1000)/Al Y8=YA*YA YC=YB*YA AT = .7853981634 + P6*YA*P7-.75*P2*PZ*P8*YB+PY*PX=*P9*YC IPASS=0 ZX1 = 1.0 ZX =0.0 25 CONTINUE IPASS=IPASS+1 IF( ZX1-ZX )28,28,27 28 IF ( IPASS-2J27 ,2 7,26 27 ZX1 = ZX CS1=DC0S(AT) CS2=CS1*CS1 SS2=1.-CS2 SS1=DSQRT (SS2 ) GX=P2*SS2 HX=GX*GX OX=HX*GX PX=OX*GX QX=PX*GX BN1=1. + .5*GX+.375*HX+.3125*GX+. 2 7 3437 5*PX+. 246C9375*QX BN2=8N1*8N1 RH0=C5*BN2*BN1 D0=CS1*SS1 PK=DO*SS2*.66666666667 QK=DO+PK SU=AT+C1*(AT-DO)+C2*(AT-CK) IFIAT-.175) 2,2,1 1 PK=PK*SS2*.8 QK = QK+ PK SU=SU+C3*(AT-QK) IFIAT-.525 ) 2,2,3 3 SU=SU+C4*(AT-QK-PK*SS2*.8571428571 ) 2 DI=C5*SU XX=Y-DI DELA=XX/RHO DELB=DELA*DELA DELC= DEL 8*DEL A ZJK=l.E-4 ZX=DABS(XX)-ZJK GB2=-3.*P2*SS1*CS1*BN2 GB3= .75*GB2*GB2-3 .*P2*(CS2-SS2)*BN2 AT=AT+DELA+G82*DELB*.5+GB3*DELC*.16666666667 IF(ZX)26,25,25 26 CONTINUE CSl=DCOS(AT) CS2=CS1*CS1 SS2=1.-CS2 SS1= DSGRT (SS2 ) GX=P2*SS2 HX=GX*GX OX= HX*GX PX=OX*GX QX=PX*GX BNl=l.+ .5*GX+.375*HX + .3125*OX+.273 43 75*PX+.24609375*QX T1=SS1/CS1 T 2= T1* T1 T4=T2*T2 T6=T4*T2 AN2=DELT*CS2 AN4=AN2*AN2 AN6=AN4*AN2 AN8=AN4*AN4 Q1 = X/(A1*BM) Q2=Q1*Q1 G4=G2*C2 Q6=Q4*Q2 H1=Q1/CS1 H2=Q2*{1. + 2.4T2 + AN2)*.16666666667 H3 = Q4=M5.+6 .*AN2+28,*T2-3.*AN4+8.*T2*AN2+24.*T4-4.*AN6+4.*T2*AN4+ 124.*T2*AN6)*0.8333333333 0-2 H9=Q6*(61.+66 2.#T2+13 2C.*T4+720.*T6)/5 04 0. D0=H1*(1.-H2+H3-H9) H4=T1*Q2*{ 1. + AN2 )*.5 H5=Q2*(5.+3.*T2+AN2-4.*AN4-9.*AN2*T2)*0.8333333333D-l H6=Q4*(61.+90.*T2+46.*AN2+4 5.*T4-252.*T2*AN2-3.*AN4-H00. 1*AN6-66.*T2*AN4-90.*T4*AN2+88.*AN8+22 5.*T4*AN4+84.*T2*AN6-19 2.*T 12*AN8)*G.27777777778D-2 H7=Q6*(13 8 5.+36 33.*72+4C95. *T4+1575.*T6)*0.49603174603D-4 DA=AT+H4*(-1. + H5-H6 4H7 ) IF(YY) 10,20,20 10 DA= -DA 20 RETURN END £ 4 4 4 4 4 4 4 * * * * * * * * 4 * 4 4 * * * * * 4 * * * 4 * * * * * * * * * * * * * * * * * * * * * 4 4 * * 4 * 4 4 4 4 4 4 * 4 * 4 4 4 4 * 4 4 4 * 4 4 4 SUBROUTINE 0 ISTAN ( X 1, Y 1, X2, Y 2, D I ST ) C SERTN COMPUTES DISTANCE BETWEEN TWO POINTS ON THE EARTH. C SUPPLY LAT/LCNG OF PCINTSIX/Y) IN DEGREES ONLY (E.G. 69.52). C SBRTN USES TRIG EQN OF P. 62 'BASIC MATHS FOR ENGNRS' BY F.M. WOOD C QUEEN'S UNIVERSITY SEPT. 1954. C 1 NAUTICAL MILE = 6076.1 FEET = 1.151 STATUTE MILES = 1.852 KM. C F=OEGREES-RADIA^S CONVERSION FACTOR. G=RADIANS-DEGREES CONVERSION FACTOR IMPLICIT RE AL *8(A-H,0-Z) F=3.14159/180. G=108G0./3.14159 ARCRAD=(DARC0S((DCOS((90.-Xl)*F))*<DCOS((90.-X2)*F))+(DSIN((90.-XI + )*F ) )*(DSIN((90.-X2)*F) )*{OCCS{ (Y 1-Y2 )*F ) ))) DIST=ARCRAD*G RETURN END C*********************************************4**4*****4*4****44*44*******444* SUBROUTINE MIN T Y(DAY, T I M E » M INUE T) C**THIS SBRTN CONVERTS SEQUENTIAL DAY AND GMT-TIME IN HOURS(E.G. 1859 HRS), C INTO 'MINUTES-OF-THE-YEAR•(¥INUET) - E.G. 12345TH GMT MINUTE OF THE YEAR. C**USE INTEGER ROUND-OFFS TC EXTRACT HRS & MINUTES SEPARATELY FROM 'TIME'. IMPLICIT INTEGE**4(A-Z) C EACH DAY CONTRIBUTES 24 FRS WHICH IS 1440 MINUTES. 10 DMIN=DAY*1440 C CHECK IF TIME=CCCO(MIDNITE). I F(T IME.NE.0000) GO TO 30 HMI N=0 MMIN=0 GO TO 4 0 C EXTRACT HOURS FROM 'TIME* - EACH HOUR CONTRIBUTES 60 MINUTES. 30 HRS=TIME/1C0 HMIN=HRS*60 C EXTRACT MINUTES FROM 'TIME'. MINUTES=(TIME-IHRS). SUM CONTRIBUTIONS. IHRS=HRS*100 MMIN=(TIME-IHRS) 40 MINUET=DM IN+HM IM+MMIN C PRINT 50, CAY, TIME, MINUET C 50 FORM AT ( IX, 'DAY/TIME CF' , 15 ,'/' , 15 , • CONVERTED TO MINUET OF', 17) RETURN END £ 4 * * * * * * * * * * * * * * 4 4 4 4 * * * * * * 4 4 44 44 44 4 44 4 4 444 4 4*4 4 4 ******* 4*4=*** ************ ****>!= SUBROUTINE UNMINT<OP IN,IYAD,EM IT) IMPLICIT REAL *8( A-H,0-Z ) IFtOMIN.NE.O) GO TO IC I YAD=0 EMIT=0. GO TO 2G 10 IYAD=IDINT(0MIN/144C.) DMI NS=OMI N- ( (DFLOAT ( IYAC ) )*1440 . ) H0UR=IDINT(DMINS/60.) RMINS=DMINS-(H0UR*60.) EMIT=HOUR*lGO.+RMINS C PRINT 3, OMIN, IYAD, EMIT C 3 FORMATt IX, 'MINUET 0F',F9.2,« CONVERTED TO DAY/TI ME OF', 17, '/',F7 C +.2 ) 20 RETURN END c c c c c c . NAV MAG $CCP Y C C C C C C C. C C c C C C c C c C c C c C c c C c C C c C c C C c *SCLRCE*3-.CC *SINK* 44444 PRCGRAM 'MAGNAVM * 4 4 * * * PROGRAM REA CS IN NAVIGATION DATA(FROM AN I/P DEVICE) £ ATTEMPTS TC MATCH MAGNETIC CATA(R E A C IN FPCM ANOTHER I/F DEVICE) TC IT. T FE MATCHED DATA ARE THEN O/P TO A THIRD DEVICE. * MAG/NAV * ARE MATCHED - 'MAGNAVM' DATA - CHRCNC PARAMETER + X/Y CG-ORD PARAMETERS ) DATA - CHRChC PARAMETER + MAG READING ) 3 WAY S{EACH ) OF NAV £ MAG CATA I/P. SEE OPTION LIST. ,hAV FA P AMETERS FRECEDEC EY A 'N* OR 'V WHERE POSSIBLE MATCH THEREFORE BASED ON CHPGNO PARAMETER MAG FARAME TERS FRECECED 4 4 4 4 4 OPTICN LIST WITH APPROPRIATE FORMAT 1) NAVIP=1 IF N AV CATA 2) =2 2 ) =3 A) MAGIP=1 B) =2 C ) =3 ....SET UP NAVIP EY A 'M' CP «G' WHERE POSSIBLE E.G E .G VNIN, MM IN» STMTS, I/P IS IF MAC- DATA I/P IS £ MAG IP VALUES IN (NINLET=SECUENTIAL MINUTES CF SET LP NAVIGATION 'FIX TIME INTERVAL', FT I NT, THE FOLLOWING MAY BE CHOSEN: M INUET + X-Y CO-CRDS(LAT-LCN) + UTM CAY+TINE+X-Y CC-OPDS OAY+TINE+NINUET+X-Y CC-CPCS. M INUET+MAG READ ING. CAY+T INE+MAG. CAY + TINE+MINUET+MAC. STMT 3. THE YEAR FROM CCCC HRS JAN. 1ST IN STMT 3. NDAY. GDAY, N-E EACH YEAR ) MSGS) - DEFAULTS. OTHERWISE. 44** LOGICAL I/O UNITS TO BE ASSIGNED: UNIT 6 = LINE PRINTER (PROCESSING MSGS £ ERROR 5 = CARD READER(*S C L RC E *) - DEFAULTS. k - NAVIGATION DATA - NO DEFAULT. 3 = MAG DATA - NC DEFAULT. 2 = C/P NAV+MAG MATCHED DATA - NC DEFAULT. fi = ERROR MSGS - *SINK* IF MSGS WANTED, *CUNNY* 44** SUBROUTINES REQUIRED: A) UNMINT - CONVERTS MINUET TC DAY+TI ML" - MANDATORY. B) TMINT - CONVERTS DAY+TIME TO MINUET - CNLY IF NAVIP=2 OR MAGIP=2. C) IGRF - COMPUTES REGIONAL MAG FIELD FOR GIVEN LAT-LCN - MANDATORY IMPLICIT RE AL*8(A-H,O-Z) INTEGER**, CF DIMENSION VTIME( 1000),VNIN( I CCC) ,NCAY(10CC ) ,XN(1 COO ) , YN(1CCO),MDAY + ( 1000 ) ,MT I ME ( 1C0O), M [NUEM (IC C 0 ) , GT IME (1C C C ) , GM, IN ( 1000 ), MAG ( 1000) , +GDAY(1000),ZT(1CO0),ZX(1C00),ZY(1CC0),ZM(1C00),VDAY(1000),GMAG(100 + C ) ,GEOGX(1CCC) ,GEOGY{1CCC ) ,ZLAT( 1CC0),ZLCN(1C0C > , I 2D AY(1CC0 ) ,ZTIME + (1000 ),Z IGRF( 1C00),ZAN0M(1CCC) **** SET UP CONSTANTS £ OPTIONS. LNCNT-.COUNT WHICH CCNTRCLS FESET OF NAG MTCH=1 SKIPS MAG-BLOCK CHECKING ROUTINE 3 MAGIP=2 NAVIP=3 FT INT = 2.C LNCNT=1 MTCH=0 **** SET LP N AV DATA FORMAT £ READ IN h AV CATA. FOR BE A UM AC CATA, NAV FORMAT IS LINE/, + N'C.CF FCLLOWEC EY FIXES+TIME AS PER FORMAT t. 5 FORMAT(16,IX,16) 6 FORMAT(I5,1X,F7.2,1X,F1C.2,1>,F15.3,1X,F15.3,1X,F15.8,1X,F15. 44*4= SET UP COUNTS ETC.. NECF=CCLNT CF NO. OF SUCCESSIVE ENDFILES READ FCR NAV CATA. CATA CCUNT AS EACH BLK READ IN - FIRST MATCH MADE. FIXES AS PER FORMAT 5 ,8) C MEOF=CCLNT OF NO. OF SUCCESSIVE E NDFIL E S pEAC FCR MAG CATA. C OP=0/P DATA POINT CCUNT. C ****START PRCCESSING LINE **** IC NECF=C C MEOF=0 SET UP IN STMT 7C CF=1 JV=1 13 GO TO ( 2C,2C,4C) , NAVIP WRITEI6, 15 ) 15 FORMA T(//1X,*I/P DATA FORMAT UNRECCGNISEC. EXECUTION TERMINATED') STOP 9 C START REACING IN NAV DATA. 20 READ(4,5,EN£>50 ) LINE, NFIX READ ( 4 ,6 ,ENC = 6C) (VM I N ( K ) , X N (K ) , YN (K ) , K=1,NFIX) GO TO 7C 30 REAC(4,5,ENC=50) LINE, NFIX READ(4,6,£NC = 6 C) (NDAY(J ) ,VTIME<J),XN(J ) ,YN(J ) , J=1,NFIX) DO 2 5 L=1,NFIX VCAY(L ) = CFLGAT(NDAY(L)) 35 CALL TMINT (VCAY (L ) ,VT IME (L ), VM IN (L ) ) GC TO 70 4C READ (4,5 ,END=5C) LINE, NFIX REAC(4,6,ENC=60) (NDAY(M ) ,VTI ME(M) ,VMIN(M),XN(M) ,YMM),GECGX(M) ,GE +CGY(M), M=1,NFIX) GO TO 70 C **** ENDFILE ENCOUNTERED. IF CNE ONLY, KEEP GCING. IF TWC, CUIT. 50 NE CF = NECF+1 IF(NEOF.GT.1) GC TC 55 GO TO 13 C END OF CAT A SINCE TWO SUCCESSIVE ENCFILES FOUND. 55 WRITE(6,57) LINE 57 FORMAT!//IX,'LAST LINE PRCCESSEC - LINE ' ,16/IX,'TWC SUCCESSIVE END + FILES READ ON UNIT 4 - END OF NAVIGATION DATA ASSUMED* ) STCF 0 C **** ENDFILE ON READING N A V CATA. SOMETHING WRCNG - GO TC NEXT LINE. 6C WR ITE ( 6, 62 ) L INE 62 FCRMAT(/1X, 'UNEXPECTED ENCFILE IN N A V DATA - APPROX. LINE #',I6/1X + , 'DATA IGNCREC - GOING CN TC NEXT LINE'/ ) C NAV DATA READ IN O.K. - NCfc SET LP MAG CATA FORMATS,THEN READ 1 DATA ELK C BEAUMAC CATA = MAGIP = 2, BLGCK= 270 (215) WHERE 2 I 5=IDAY,ITI ME,MAG. 7C MECF = C NEOF=C IMAC-=270 C **** SIGNAL THAT N AV CATA REAL IN O.K. WRITE(6,73) LINE 73 FORMAT( IX,'NAV CATA FCR LINE NO.',16,* READ IN C.K.' ) C ....IF LINE BEING PROCESSED IS AFTER F IR ST(L IKE ) , DON'T READ ANY MAGS BUT C JUST CONTINUE MATCHING. C ....ANY TIME MAG CATA IS READ, KG MUST EE RESET =1. 77 IF(LNCNT.GT.l) GO TO 1S4 78 KG=1 GC TO (8C,E5 ,SC) , MAG IF 7 FORMAT (90 (91 5) ) WRITE(6,15) STOP 7 8C R E A D (3,7 »£ N C = c 5) (GMIN(I),MAG(I) , I = 1,IMAG) GO TO ICC 85 READ( 3,7,ENC = 95) (MDAY(I),MTIME(I),MAG(I )» MDA Y{I + I),NT I ME(I+ 1) ,MAG + ( 1+ 1) ,MDAY(1 + 2) , MTI ME(1 + 2),MAG( 1+2 ) , 1 = 1 ,268 ,3 ) DO 8 7 M= 1, IM AG GCAY(N)=CFLCAT(MOAY(M ) ) GTIME(N )=DFLOAT(MTlME(N) ) 87 CALL TMINT(GCAY( M) ,GT INE ( M ) ,GMN( N) ) GC TC 10G 9C READ(3,7,ENC=95) ( MD A V < I ) , NT 1N E < I ) , GN IN ( I ) , M AG ( I ) , GO 10 ICC **** ENDFILE ENCOUNTERED. QUIT ONLY IF 95 NECF=NECF+1 IF(MEOF.GT.l) GO TO 97 GO TO 78 **** END CF CATA. NO MORE MAG CATA TO 97 WRITE(6,98) GNIN(l) 98 FORMAT(//IX, 'MAG DATA BLOCK STARTING 1= 1, IM AG ) 2 SUCCESSIVE EOFS READ. MATCH NAV DATA. + BE READ •/IX,'TWO SUCCESSIVE ENDFILES AT MINUET CF',F10.2,* LAST TO READ ON UNIT 3 - ASSUMED NO DATA'/) C C C ICO +MCPE MAG STOP 1 **** BOTH MAG 6 NAV DATA READ IN 0 SUCH AS CAY OR TIME = 9999, OR SKIP DAY/TIME CHECK IF MAG I F = 1 . MEOF=0 IFlMAGIP.EQ.l ) GO TO 115 CC 110 N=1,1MAG IF (MDAY(N).EQ.9999) GC TC 106 IF(MT IME (N ) .EG.9999) GO TO 1C6 ..SPECIAL IF STMTS FOR EEAUNAC CATA IF(NDAY(N).EQ.155) GC TC 1C6 IF(MDAY(N).GT.365) GO TO 1C6 GC TC 110 GNIN<N)=999999.9 WRITE(c,108) LINE, MCAY(N), FORMAT(IX,'FOR LINE',16,' - + 216) 11C CCNTINUE DO 120 N=1,IMAG GNAG(N)=CFLCAT(NAG(N) ) IF(GMAG(N).NE.C.) GC TC 12C GMAG{N ) = -9999.9 WRITE (6,117) LINE, MDAY(N), FORMATdX,' ******* FCR LINE #',I6,« AT +=0 SO SET TO -9999.9 FOR PLOTTING *****•) 120 CCMINUE C **** MAG DATA READY FOR NATCHIISG TC NAV DATA K. CHECK MAG DATA FOR CCD VALUES. MAG = 0 IN BEAUMAC DATA. DAYS 155 I 955 INVALID. 1C6 108 115 MTIME (is ) GMIN SET TO 999999.9 FCR DAY/TIME OF' MTIME (N) 117 CAY/TIME=',2I5,' - MAG ON BASIS OF SEQUENTIAL MINUTE C C c c 13C 132 134 PARAMETERS 'GMIN' S 'VNIN' RESPECTIVELY. CHECK IF MAC- BLOCK IN HAND IS TOO FAR ALONG IN TIME FCR MATCH. IF SO, BACKS PACE CNE FILE CF MAG CATA. IF FIRST MATCH MADE ALREACY, SKIP TC STMT 230. IFIMTCF.EQ.1 ) GO TO 23C I F(GM IN(1 ) .NE .999999 .9) CO TO 132 ..GMN(l) NCT USEABLE FCR TEST - USE NEXT GMIN INSTEAD. IF(VMIN( 1).GE.GMIN(2)) GC TO 180 GC TO 134 IF(VMIN(1).GE.GNIN(1)) GC TC 180 ..BACKSPACE REGUIRED. SKIP CVER FILEMAPK EY REACING, USING ENC= EXIT BACKSPACE 3 WRITE (6,13 5) LINE, GNINU), VM IN ( I ) F0RMATI/1X,' BACKSPACE UNIT 3 CALLED - GMIN MUST EE .GT. VMIN' •, F13.3, • .GT .',F13.3,» ?•/) 14C READ(3,140,ENC=145) FORMAT IF c.3) . .EOF NOT ENCOUNTERED EC F SOMETHING WRONG. SKIP TC NEXT LINE WRITE<6,143) LINE 143 F0RMAT(/1X,' ENDFILE NCT FCUNC CN READ/EACKSP AC E LINE #',I6,« + NOT PROCESSED • /) GC TC 10 C ....BACKSPACE/SKIP - EOF C . i< . R ECFECK MAG BLCCK IF O.K. 145 WRITE(6,147) LINE 147 FORMATdX,' LINE #',I6,« BACKSPACE /SKIP-EOF O.K. 1) GO TO 130 C **** MAG BLOCK IN HAND IS C.K. ** NATCH BEGINS ** C SCAN MAGS TILL GM IN MATCHES VMIN. IF NOT FOUND, CHECK C DURING EACH SCAN : IF GMIN IS MISSING, GM IN IN HAND fclLL BE -GT.VMIN. C ROUND T\ftC - FIRST MATCH MACE - PEST SHCULC EE EASY TO MATCH. C ....MAKE SURE WE'RE NOT OUT OF DATA. BOMB OUT IF NAV, GET NEXT BLOCK IF MAG. 18C IF(JV.GT.NFIX) GO TO 187 IF(KG.GT.IMAG) GO TO 78 184 IF(VMIN(JV).EC.GMIN(KG)> GO TO 2C0 C ....NC MATCH. CHECK IF SCANNED PAST MISSING GMIN. IF NOT, GET NEXT GMIN. IFCGMIN{KG).EC.999999.9) GC TC 195 IF(GMIN(KG).GT.VMIN( JV) ) GC TO 19C C NOT SCANNEC PAST - WANTED GMIN STILL AHEAD - SCAN FOR IT. K G = K G + 1 GO TO 18C 187 WR ITE(6, 1£8 ) 188 FCPMAT(//1X,• OUT OF NAV CATA BEFORE FIRST MATCH - SOMETHING WRO +NG •//) C GET NEXT NAV LINE CATA. LNCNT = LN CNT + 1 GC TC 10 C ....SCANNED PAST - WANTED GMIN MISSING. GET NEXT VMIN £ RETRY MATCH. 19C WRITE(8,193) JV ,KG , VM IN{JV ) ,GMIN(KG) 193 FORMAT(IX,'AT 190 - SCANNEC PAST COS GMIN MISSING. JV/KG ARE',217, +' VMIN(JV)/GMIN(KG) APE',2F13.3) JV=JV+1 GO TO 180 C ....GMIN NCT US EA EL E - SKIP TC NEXT GMIN ANC RETRY MATCH. 195 KG=KG+1 GO TO 18C C **** MATCH RCUNC ONE WON. FIRST MATCH FOUND. PRINT MSG. C PAD MAG UTH FIRST DIGIT '5* - COMPUTE REG ICNAL( IGRF ) £ ANOMALY. 2CC ZT(OP)=VMIN(JV) ZX(CP )=XN(JV) ZY(CP)=YN(JV ) ZLATIOP)=GECGX(JV) ZLCNIOP)= GEOGYIJV) CALL UNMINT(ZT(OP ), IZCAY(OP ) ,ZT IME (OP ) ) ZM(CP)=GMAG(KG)+5CCGC. CALL IGRF(ZLAT(CP),ZLCN(CF),ZIGPF{OP)) ZANOM(OP )=ZM(CF)-ZIGRF(OP) WRITE(8,207 ) LINE,VMIN(JV ),GMIN(KG),2 X(OP ),ZY(CP),2M(0P ) 2C7 FORMAT (IX, 'LINE i ' . I c , ' FIRST MATCH FCLNC AT NAVT IME ' , Fl2 .3 , ' - MA + GTIME',F12 .3/IX,'CORRESP X-Y S MAG ARE',3F15.3) C ....UF C/P CATA PCINT CCUNT. 0P=0P+1 WRITE(8,2C9) OP 209 FCPMATdX,'AFTER 200, CP IS NOW',17) C 44**N0W STARTS MATCH ROUND I V> C. PEST CF CATA. 220 JV=JV+1 KC- = KG + 1 IF(KG .LE . I MAG) GO TO 221 MTCH=1 GO TO 78 221 CCNTINUE WRITE(8,223) JV,KG 223 FORMAT( IX, 'AFTER 2CC-22C, JV/KG ARE',21 7) 23C IF(VMIN(JV ) .EC .GM IN(KG ) ) CO TC 300 C ...WANTED GMIN TC COME, MISSING CR 999999 .9. NCT E GMIN CAN EE .LT.VMIN C 'CCS TIME INTERVALS IN MAG £ NAV CATA MAY CIFFER. C IF GMIN.LT.VMIN, GET NEXT MAG WHICH MAY BE WANTED ONE. 1F(GMIN(KG).GT.VMIN(JV)) GC TC 236 KG=KG+1 IF (KG.LE.IMAG ) GO TO 2 30 MTCF=1 GC TO 76 C ...GMIN.GT.VMIN - IF GM IN = *3 9 9 S 9 9. 9 GET NEXT MAG. IF NOT GET NEXT NAV 'COS C WANTED GMIN MISSING. 236 IF(GMIN(KG).EC.999999.9} GC TO 260 WR ITE(8,2 43 ) GMIN(JV) ,GDAY(JV ) , GT I ME(JV ) 243 FORMAT ( IX, 'MAC- M INUTE ' ,F 1 C. 3 , • MISSING OR NO GOOD. DAY/TIME OF ', + 2F10.3,' **********•) JV=JV+1 IF (JV .LE.NF IX) GO TO 22G CF=CP+1 GO TO 4GC C ... .GMIN = 99Sccc. c - GET NEXT MAG. 260 KG=K G+1 IF(KG.LE.IMAG) GO TO 230 MTCH=1 GO TO 70 C **** C NE MCRE MATCH MACE. STORE IN O/P ARRAYS AND TRY NEXT MATCH. C AGAIN PAD MAG WITH FIRST CIGIT »5» - COMPUTE REGIONAL € ANOMALY. C DCN'T LOAD DATA INTC C/F ARFAY IF EAC MACS(TIMES REJECTED ALREADY) 3C0 IFlGMAGtKG ) .NE .-9999.9 ) GO TC 304 WRITE(6,302) VMIN(JV) 3C2 FORMAT(IX,****** AT APPRCX MINUET CF',F10.2,» MAG VALUE WAS ZERO + - NO DATA O/P FOR THAI TIME *****») IF(JV.LT.NFIX) GO TO 220 0P=0P+1 GO TO 400 304 ZT(CP)=VMIN(JV) ZX(CP)=XN(JV) ZY(OP )=YN(JV ) ZLAT(OP)=GECGX(JV) ZLCN( CP) = GECGY (JV ) CALL LNMINT(ZT(CP) ,12CAY(CP ) ,ZT I ME (CP ) ) ZM(OP)=GMAG(KG) + 5CCCC . CALL IGRF(ZLAT(OP),ZLON(OP ),ZIGRF(OP) ) ZANCM(CF)=2M(CF)-2IC-RF(CP) WRITE(8,3C9) VMIN(JV) ,GMIN(KG) ,ZM(CP),ZX(CF),ZY(CP),ZLAT(CP ) ,ZLON( + 0P ) 309 FCRMATdX, 'MATCHED VM IN/GM IN= * , 2 F 1C .3, ' M AG/X / Y= •, 2F 15. 2 , 2F 1 5. 8 ) C ***** SPOT CHECK MSG. IF (MOD (OP, 1O.EQ.0) WRITE (6,211) LI NE , C P , VM I N ( J V) ,XN ( J V ) , Y N ( JV ) , GE + CGX ( JV ) ,GECGY ( JV ) ,GM IN (KG ),MAG (KG ) , I ZD AY (OP ) ,7. T I ME ( OP ) , ZT ( OP ) ,ZX(0 +P),ZY(OP),ZLAT(CP),ZLCN(CP),ZM(CF) 311 FORMATdX, »SPCT CHECK - LINE W',I6,« - ',I3,'TH CATA POINT •/ + 1X,»I/P NAV - MI NUET= »,F9.1,' - X N= ' , F 10 . 1 , • + YN=' ,F10.1,• GECGX=',F13 .8, • G£OGY=',F13.8/IX,4X,'MAG - M +INUET= ',F9.1, 70X,' MAG=',I5/1X, 'C/P - CAY/TIME/M + INUET= «, 14, •/• , F6.1,'/',F9.1, • - XN = «,F1C.1,» YN=*,F1C.1,* LAT +=«,F13.8, ' LON=', F13 .8, ' MAG=«,F7.1) C CHECK IF END CF LINE PE ACHE C. IF YES, WRITE G/P ARRAY S GET NEXT LINE. IF(JV.EG.NFIX) GO TO 4CC C ....NCT END CF LINE. UP O/P CATA POINT COUNT 6 TRY NEXT HATCH. OP=CP+l GO TO 220 C *** LINE MATCHED. WRITE C/P ON UNIT 2 £ PRINT MSG. GO ON TO NEXT LINE. 4C0 WRITE(2.409) LINE, CF 4C9 F0RMAT(1X,I£,1X,I6) WRITE(2,413) (IZDAY(J)»ZTIME(J),ZT(J),ZX(J) ,ZY(J) ,ZLAT(J),ZLCN( J) , + ZM(J),ZIGRF(J) , Z ANCM(J ) , J=1,CF ) 413 FORMAT(14,1X,F6.1,1X,F11,2,1X,F12.3,IX,F12.3,1X,F13.8,IX,F 13 .8,IX, +F7.1,1X,F7.1,1X,F7.1) C ....WRITE ENC-CF-FILE ON UNIT 2. ENDFILE 2 WRITE(6,417) LINE , OP 417 FORM AT(IX, 'LINE', 16, ' MATCHED £ O/P',16,» FIXES : GOING CN TO NE + XT LINE'//) C ....UP LNCNT SC KG ISN'T RES ET=1 'CCS NEXT LINE MAG MAY EE IN BLCCK IN HAND. LNCNT = LNCNT4 1 GC TO 10 END £ 4 * * 4 * * 4 4 4*4*4*4444444*****4*****44444444******444444 444*444444444 44444444*4444 SUBROUTINE IGRF(DLAT,DLON ,GIGRF) C C PROGRAM CCMPLTES INTERNATIONAL GEOMAGNETIC REFERENCE FIELD(THE THEORETICAL C REGIONAL MAGNETIC FIELD FCR THE EAPTF) AT ANY LOCATION. COMPUTATIONS C ARE DONE FROM PGRF COEFFICIENTS SET FOR AREAS DEFINED, C PGRF COEFFICIENTS FOR AREAS MUST BE SET IN PROGRAM £ IF MORE THAN ONE SET C CF COEFFICIENTS ARE REGLIREC, ENSURE 'IF' STATEMENTS WILL INITIALISE THE C APPROPRIATE COEFFICIENTS ACCORDING TC CO-ORDS CF THE LOCATION I/P. C I/P LCCATICN LATITUDE £ LONG ITUCE(DLAT S DLON) IN DECIMAL DEGREES AND C C/P WILL BE THE IGRF VALUE(GIGRF). C COMPUTATIONS ADAPTED FROM BEDFORD INSTITUTE PROGRAM F69RX4. C **** SET I/O UNIT 5 = PGR F COEFFICIENTS I/P DEVICE. C 8 = MESSAGES £ D E E U G PRINTS. FOCCUE GCH J AN 1972. IMPLICIT REAL *8(A-H,0-Z ) C **4*SET LAT/LCN LIMITS OF AREA COVERED BY COEFFICIENTS. C BLA TA = B IG(HI) LAT CF AREA A; SLAT A=SMALL(L0 ) LAT OF AREA A; ETC.. BLA TA = 75 . SLATA=69. ELCNA=137 . SLCNA=125. BLATB = 75 . SLATB=69 . BLCNB=149. SLCNB=137. C 2C READ(5,23,END=99) DLAT,CLCN C 23 F0RMAT(F2C.IC,F20.1C) X=CLAT Y = D L 0 N C *=S<*CFECK IF LON IS IN LON DEFINED BY AREA A OR AREA 8. IF(Y.GT.ELCNA) GO TO 3C IF(Y.LT.SLCNA) GO TO 3G C ....Y IS IN AREA A IN LCN VALUE - CHECK LAT VALUE . IF(X.GT.ELATA) GO TO 4C IF(X.LT.SLATA) GO TO 40 C ....LAT £ LON C.K. - LOCATICN X/Y IS IN AREA A. GO TO 30 0 C 4444NCT IN AREA A'S LON - CHECK IF IN AREA B'S LON - IF NOT, QUIT. 30 IF(Y.GT.ELCNE) GC TC 999 IF (Y.LT.SL0N8 ) GO TO 999 C ....LCN IN AREA E - CHECK LAT - IF NOT, QUIT. IF(X.GT.ELATB) GO TC 999 IF{X.LT.SLATB) GO TC 999 C ....LAT S LON C.K. - LOCATION X/Y IS IN AREA B. GO TO ACC C ***«Y NOT IN AREA A LAT-WISE BUT IN LCN-WISE ONLY. CHECK IF IN AREA B LAT-WISi AC IF(X.C-T.GLATB) GO TO 9 99 IFtX.LT.SLATE) GO TO 999 C IN AREA B LAI-WISE - CHECK LCN-WISE. IF (Y .GT.ELONB) GO TO 999 IF(Y.LT.SLONB) GO TO 999 C ,...LAT £ LCN C.K. - LOCATION X/Y IS IN AREA E. GO TO 4CC C **** INITIALISE APEA A'S PGR F COEFFICIENTS. 3CC AO = 4.247960403E 04 A 1 = -2.451645372E 03 A 2- 2.57 4685E12E C3 A3 = 1.219954594E 01 A 4 = 4.2425C833CE 01 A5 = -2.556C756C3E C 1 A6= 1.204279A82E- 01 A7 = -1.412A72CC5E -01 A8 = -3.374476887E -01 A9 = 1.047481346E- 01 BO= 6.987690585E- 04 Bl = 1.268989639E- 03 B2 = -1.62184C51CE -C3 B3= 5.36427222EE- 04 84 = -3.242870896E -04 GC TO 5CC C *4<*INITIALISE APEA B'S PGRF COEFFICIENTS. 40C A0= 2.020575714E 05 A 1 = 8.973467845E 02 A2 = -1.489226462E 03 A3= 2.0A8578270E 0 1 A4 = -8.203015717E 01 A 5 = -7.30114745CE CO A6 = -2.822256954E -C 1 A7 = 1.811406643E- 01 A8 = 1.116083454E 00 A9 = 4.382587724E- 02 B0 = 5.5668CCC97E- 04 Bl = -5.3A15A829 1E -04 B2 = 9.37A785339E- 06 83= -4.6392 94727E -03 B4 = -6.A853C55C2E -05 GC TO 500 5CC GIGRF = A0 + A1*X+A2*Y + A3*X*Y4AA*{X**2) + A5*(Y**2) + A6*(X**2)*Y-+A7*X*(Y* + *2) + A8>UX**2 )+A9*( Y**2 ) + 8C*{>**3)*Y + B1*X*(Y**3) + B2* (X**2 )* (Y**2 ) + B +3*(X**4 ) + E4<(Y**4) V.PITE (8*33) DLAT,DLON, G IGRF 33 FORMAT(IX, 'AT LAT/LON 0F' , F 1 5.8 ,1X , Fl5.8 , • IGRF COMPUTED =',F10.3) GC TO 97 C ****DLAT/DLCN FCR LOCATION NCT IN AREAS FOR WHICH COEFFICIENTS SUPPLIED. 999 0IGRF=-1CE3C W!RITE( 6, 997 ) CLAT, DLON 997 FCRMATdX, • C L AT / DLON ' , F 1 5 . 8, 1X.F15..8, • NOT IN PGRF AREAS *4*4***« ) GC TO 97 C 99 STOP 97 RETURN END SUBROUTINE TM INT < DAY,TIME,SMIN) C THIS SUBROUTINE CCNVEPTS SEQUENTIAL CAY+TIME INTO SEQUENTIAL MINUTES- IMPLICIT R EA L*8(A-H ,C- Z ) C 4 READ(5,c,END=^c ) DAY,TIME C 6 FCPMAT(F10.3»1X,FIO.3) C EACH DAY CCNTRIEUTES 144C. MINUTES. 1C DMIN=DAY*144C. C CHECK IF T IME=CCCC.{MIDNITE) SO WE DON'T TRY TO DIVIDE BY C. IFITIME.NE.C. ) GO TO 30 HM IN = C . XMIN = 0 . GC TC 40 C EXTRACT HRS FROM 'TIME' S CCNVEPTS HPS TC MINUTES. 3C IHRS = IDINT(TIME/1G0. ) HMIN= IHRS*60. C EXTRACT MINUTES FRCM 'TIME'. JHRS=IHRS*1CC HRSJ = DFLOAT(JHRS ) X MIN=TIME-HRS J 4C SM I N =DMIN + H MIN+XMIN C WRITE(8,5C) CAY,TIME ,SMIN C 5C FORMATdX, 'DAY/TIME OF • , F 1 C . 3 , 1 X ,F 1C . 3 , ' CONVERTED TO SMIN 0F',F15 C + .3 ) C GC TO 4 C 99 STOP RETURN END SUEROUTINE UNMINT(OMIN,IYAD,EMIT) IMPLICIT REAL<8(A-H.C-Z ) IF(OMIN.NE.C) GC TO 1C IYAC=0 EM IT=0. GC TO 20 1C IYAC=IDINT(CMIN/1440.) CMINS=OMIN-((DFLOAT!IYAD))#1440. ) HCUP=IDINT(CMINS/60.) RMIN S = DMIN S-(HOUR* 6C . ) EMIT = F0UR*1CC. + RMINS C PRINT 3, CM IN, IYAD, EMIT C 3 FCPMATdX,'MINUET CF«,F9.2,' CCNVERTEC TC CAY/TIME OF', 17, '/',F7 C +.2 ) 2G RETURN END SCCFY *SKIP *SINK* $CCFY *SCURCE*a-.CC *S INK* C ******* GPIDDER ******* C GRICDER IS A PRCGRAF khlCr IS USED IF SEVERAL Z-VALLES ARE TC BE GRIDDED ANC C P LOTTED. NORMALLY, EACH SET OF Z-VALUES HAS TO BE GRIDDED SEPARATELY BUT C THIS LSES UP UNECESSARY CPU TIME SINCE THE GRIDDING FOR EACH SET OF Z-VALLES C IS THE SAME PROVIDED THE SAME X-Y CC-CRCS APE USEC EACH TIME. C SINCE TEE GRIDDING IS THE SAME FOR EACH SET OF Z-VALUES, IF WE CAN RECORD C THE GRICCING INSTRUCTIONS FOR A SINGLE GRIDDING RUN, WE CAN THEN USE THESE TC C LCAD ( V*E IGHTI NG CCPRECTLY ETC..) ANY NUMBER CF SETS OF Z-VALUES. THIS IS WHAT C GRICCER DOES - IT 'REMEMBER S * THE GRIDDING INSTRUCTIONS. C THE CRICDING FROGS ARE COURTESY OF MIKE PATTERSON, DEPT CF GEOGRAPHY, LBC. C C IN CALL MXGEN(XP,IX,YP,IY,DATA,N) : N=+7CCC IF MXCEN-CUTPUT TO SEO. FILE C =-7CCC MAG TAPE. C FCR TAPE, PPECECE TFIS PRCG EXEC BY MOUNTING TAPE S LAEELLING IT WITH A C DATA-SET NAME VIA THESE CCf'MANCS : SCCPY *SCURCE^ TO *TAPE*SCC C DSN MXGEN-OUTPUT C $ ENDF IL E ... THESE COMMANDS ON CARDS. C CONCAN TENATE SBRTN MXGEN/M X PA N C TC EE SURE... C SET LOGICAL UNITS 4 = I/P FCPMAT CF CATA TC EE GPICCEC. C S X-Y CC-ORDS OF GRID ORIGIN(2F2C.5) C £ MAX X-Y CC-CRDS OF GRIDI2F2C.5) C £ +1 CP -1 FOR ISIGN - SIGN CF N(I2) C 3 = X-Y CC-CRDS CF PCI NTS TO BE GRICCEC. C 1 = GRICCER O/P - THESE ARE THE GRIDDING INSTRUCTIONS. C TO CHANGE GRID SIZE, CHANGE CIMENSICNS CF XP S YF AND IX 2 APPROX STMS 3C+ C *** WARNING : DO NO 1 USE DOUBLE PRECISION NUMBERS *** DIMENSION FMTK20), XP(5C), YP { 5 C ), D A TA { 3 , 7 COG ) , ATAD(3,7CCC) NPT S = l C ....READ IN I/P FORMAT REAC{4,10) FMTI 1C FGRMAT(20A4 ) C ....READ IN X-Y CC-ORDS TC EE GPICCEC. 2C REAC(3,FM.TI,END = 99) {D A T A { I , N PT S ) , 1 = 1,3) NF7S=NPTS+1 GC TO 20 C ....END OF FILE READ - ASSUMED NO MORE DATA TC BE GRIDDED. 99 NFTS=NFTS-1 IF(NPTS.LE.Q) GO TO 9CC WRITE(c,3G) NPTS 30 FORMATdX, 'LAST DATA POINT READ IN WAS NC',16,' ANC WAS ...') WR ITE(6,FMT I ) ( C AT A( I ,NP T S ) , 1=1,3) C SET IX-IY GRID SIZE. IX=50 IY = IX C ....NCW READ IN X- £ Y-CCCPES CF GRIC ORIGIN - TO BE PLOT ORIGIN ALSO. REAC(4,4C) XMINT, YMINT REAL(4,AC) XMAXT, YMAXT 4C FCPMATl2F2C .5 ) WRITE(fc,41) XMINT, YMINT 41 FORMATdX, 'I/P GRID ORIGIN CC-ORDS IN X-Y 2F15.3) WRITE(6,14) XMAXT, YMAXT 14 FORMAT(IX,•I/P MAX CC-CRCS CF GRIC IN X-Y ..',2F15.3) C ....READ IN SIGN TC KNCW IF MXGEN O/P IS FILEl+VEJ CR TAPE(-VE). READ(4,42,END=43) ISIGN 42 FORMAT(12) WRITE(6,46) 46 FORMAT (IX, 'SIGN SPECIFIED : + 1=FILE; -1=TAPE O/P FOR MXGE IS' ) GC TC 5C C ....NC SIGN SPECIFIED - ASSUMED FILE C/P - ISIGN=-U. 43 WRITE(6,44) 44 FCRMATdX, * NC SIGN SPECIFIED - ASSUMED MXGEN O/P TO GO CN FILE') ISIGN=1 C ....NOW REFERENCE ALL DA 1A >-Y CCOPCS TO ORIGIN SPECIFIED. 50 CO 52 I=1,NPTS ATADt 1, I )= (DATA (1 ,1 l - X M M ) 52 ATAC ( 2 , I )= (CATA (2 , I )-VM M ) WRITE(6,51) ATAD(1,NPTS), ATADl 2 ,NPTS ) 51 FCRMATdX,•PECRIGINED LAST DATA FCINT : X =',FJ5.3,' V =',F15.3) C ....SET LP GRID CROSSING CCCRDS XP( ) 6 YF( ). C REMEMBER ORIGIN IS (XNINT, VMIN1).... XP( 1 )=0 . YP(1)=0. C ....SET LP GRID INCREMENTS. CXP=(XMAXT-XMINT )/( IX-1 ) CYF=CXF DO 53 K=2,IX XP (K )=XP (K- 1 MDXP 53 YF(H)=YP(K-1HCYP WRITE(6,54) XF(1), YP(1), DXF 54 FORMAT(IX, 'GRID IS TC EE ORIGINEC AT X=',F15.3,« Y=«,F15.3,' WITH + GRID I NT E R V A L = ' , F .10 . 3, * AXES UNITS') WRITE(6,62) XP(IX), Y F ( IY ) 62 FORMAT (IX, 'GRID STRETCHES TC X =',F15.3,' Y =«,F15.3) C ....SET UP NO OF POINTS «N' - +VE IF FILE, -VE IF TAPE O/P FCR MXGEN. N = NFTS* ISIGN C ....CALL GRID GENERATOR - NPTS +VE IF FILE, -VE IF TAPE FCR MXGEN O/P. CALL MXGEN(XP,IX,YP,IY,A T A D,N) WRITE(6,55) 55 FORMAT(IX,'NXGEN CALLED £ ALL POINTS GR I 0 0 EC' ) STOP 1 C ....NO CATA TO BE GRIDDED SINCE ENDFILE READ CN FIRST ROUND. SCC WRITE(6,9C9) 9C9 FORMAT(/IX,•NC DATA TC EE GRIDDED?? UNIT 3 EMPTY??') STCF 9 END £4444444444*4***4444*4**444******444444*** C MXGEN LISTING AVAILABLE ONLY FROM C MIKE PATTERSON CEPT CF GECGPAPhY UEC SCOPY *SKIP *SINK* $COPY *S0URCE*3-.CC *SINK*a-CC C ***** PLOTTER ***** C C IN PLOTTING DATA FROM SCATTERED POINTS, THESE MUST FIRST BE •EXPANDED' TC C A SQUARE GRIC. MXGEN, A GRID GENERATOR PROG, KEEPS THE EXPANSION C INSTRUCTIONS £ FOR THE SAME DATA POINTS, ONLY THE Z-COORO TO BE PLOTTED C NEEDS TO BE I/P SIMCE THE X£Y CO-ORDS ARE ALREADY KNOWN(BY MXGEN). C WITH THE MXGEN GRID EXPANSION INSTRUCTIONS ACCESSIBLE VIA UNIT 1, THE C Z-COORDS I/P ARE WEIGHTED ETC.. BY MX PAND. C AFTER THE Z-COORDS ARE GRICDED, SBRTN * PL0T2D' IS CALLED TC PLOT THE DATA. C THIS PROG WRITTEN INITIALLY FOR MAX OF 7GGG DATA POINTS TO BE ON C A 50 X 50 GRID. C SET THE I/O UNITS 1 = MXGEN C/P(GRID GENERATING/WEIGHTING INSTRUCTIONS C OBTAINED FROM MXGEN RUN) C 2 = Z-COORDS TO BE GRIDDED/PLOTTED. C 4 = Z-CCCRD FCRMAT FOLLOWED BY C PLOT-SIZE ALCNG Y-AXIS, C NO. OF CONTOURS TO BE PLOTTED IN RANGE OF Z, C X-CCCRD/Y-COORD OF PLOT ORIGIN, C INCREMENTS/PLCT INCH ALONG X- £ Y-AXES RESP. C 7 = GRIDDED DATA : O/P IN BINARY. C 9 = PLOT COMMANDS O/P. C *** RUN THIS PROG WITH MXPAND ANC PLCT2D ETC.. CONCANTENATED. C MXPAND/MXGEM ARE COURTESY OF MIKE PATTERSON, GEOGRAPHY, UBC C PLCT2D AND SCAL2D COURTESY OF TAD ULRYCH, GEOPHYSICS, UBC. C THIS JIG-SAW PIECEWORK PUT TOGETHER LO FEB 1972 ROCQUE GOH GEOPHYSICS UBl C COMMON/DEBUG/FLAG LOGICAL FLAG FLAG=.TRUE. DIMENSION FMT(20), XPI5C), Y P{ 50 ) , GRI0(50,50), CATA(7000 ) C ****R£AD IN Z-COORD FORMAT FROM UNIT 4 READ(4, 10) FMT 10 FORMAT(20A4) WRITE(6,12) FMT 12 FORMAT(IX, 'Z-COORD FORMAT IS..', 20A4) C ****READ IN PLCT PARAMETERS - INITIALISE PLOT SUBROUTINES. CALL PLOTS READ(4,20) SZY READ(4,22) NCONT READ(4,24) XCCOR, YCCCR READ(4,24 ) DX, DY READ(4,22) IX 20 F CRMAT (F20. 5) 22 FORMAT(12) 24 FORMAT(2F20.5) WRITE(6,3 0) SZY,NCONT,XCOOR,YCOOR,CX,CY,IX,IX 30 FORMAT(IX, 'PLOT PARAMETERS I/P ARE..'/IX, 'SIZE Y =», F 1 0 . 3 , 3 X , + 'N0. OF CONTOURS IN RANGE =',I6/1X, 'X- £ Y-CCORDS OF PLOT ORIGIN +=', 2F13.3/1X, ' INCREMENTS ALONG X- £ Y-AXES ARE', 2F1C.3/1X, 'GRI + D IS TO BE' , 16, » X • , 16/) C ****CALL YSIZE IF LARGE PLOT REQUESTED. IFtSZY.GT.10.5) CALL YSIZEI29.0) I Y= I X IDIMX=IX IDM= IX S3XV 3 H I i O l d 3 AZS/( T-AI ) l $ m 3 = A 0 (0 *0 "11 *A0) 31 x z s / ( x - x i ) i t f o i d = x a ( o * o * n * x a ) d i AD+(1-AI)IV313/A7S * ( 1-I)1V013=( I)dA Z AI*T=I z oa ( I-XI ) 1VD13/XZS* ( T-I ) 1V013 = ( I )dX I x i * i =i \ oa 31V 3 S Oi SAV88V 3 H I dfl 13S 3 A3+AZS=dZS 0*Z/(AZS-9nS)=A3 0*6Z=8nS (T'OT'iO'AZS)3I o*oT=ans i O l d 3 H 1 U31N30 3 ( I-A I UV013/ (T-X I )1V013*AZS=XZS N01133ai0 X 3H1 NI 3ZIS 3Hi 3NIW83i3a 3 (OOt)dA *O0C) dX*(War*W3I )D NDISN3HI0 * * * * * * * * * * * * * * * * * * * * * * * * * * * o 03138V1 33 Oi H001N33 H i ! 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UVWaOd SZ (5i*9)31I8M o s 4 i = i * o s * i = r • ( r * i ) a i u D ) ) u ) 3 i i a M * i i 3 v i v a 0333 i a s 3iIaM•••• 3 ( (5 *ET90l ) / • ** * SI A V b i i V i . Q i y g . i JO OT X OT I S a i d i ' X I UVHHOd S9 ( 0 i * i = i M o i * i = r * ( r * n a i y o ) ) ( S 9 * 9 ) 3 i i y M (»iX3M ONIiiDld - 03031*19 S i NI Od . * XT ) i VW 803 09 (09*9)31I8M (sid N * v i v a * A i 'xi*09 'aiyg)aNVdxw I I V D •N33XW rf08d SNOUOnUiSNI 3.\iia3189 9N I S f l SOaOOO-Z 0189**** 3 (SidN)ViVO (iW3'9)3iiyM ( t:iNIOd VIVO 1SVT.'9I ' • = N I 0V38 SINlOd VitfO 3 0 * 0 N . 'XI)IVWUOd ZS S i d N (ZS*9)3iI8M I-SidN=SidN OS •siNiod v i v a 3*ow ON aswnssv - a o a 3ii3aN3**** o 0*7 01 OD T+SldN=SidN ( ( s i d N ) tfitfa) (05=a \ i3* iwd'z)av3a ov I=SidN *G3il01d/030QI89 38 0 1 SC1H00D-7 N I 0V38 HON**** D T =H11 XI =AQV CALL AXIS(0.,CY,1H , - 1, SZ X, 0 . , XCOOR , DX) CALL AXISt0.,CY,1H ,+1,SZY,90.,YCOOR,CY) CALL PLOT(G. ,SZP,+3) CALL PLOT(SZX, SZP,+2) CALL PLOT (SZX,CY,+2 ) C NOW SCALE THE MAP CALL SCAL 2D(G, IDM, JDM,IX,IY,GMAX,SMI N,NCCNT,CMAX,CM IN,CI NT) C WRITE THE RELEVANT VALUES WRITE'6,111) GMIN,GMAX,CM IN,CMAX,CI NT 111 FORMAT!//' MINIMUM VALUE CN MAP =',LPE15.5/' MAXIMUM VALUE ON MAP += ', 1PE15.5/• MINIMUM CONTOUR VALUE =',lPE15.S/» MAXIMUM CONTOUR VA +LUE =«,1PE15.5/' CONTOUR INTERVAL =»1PE 15 .5///) C PLOT THE CONTOURS C LABEL EVERY LTH CDNTOUR ONLY IF(LTH.EG.O) LTH=1 SEP1 = 3.0 IFISZY.LT.6. 1) SEPl=2.C IF1SZY .GT.10.5) SEP1=4.0 LCCP=-1 NUMC=(CMAX-CMIN) /C INT + 1.1 CN=CMIN DO 3 I=1,NUMC L0CP = L00P+1 SEP=0. IF(LOOP.EQ.1) SEP=SEP1 CALL CNTOUR(XP,IX,YP,IY,G,IDM,CN,SEP,CN) CN=CN+CINT IF(LOOP.EQ.LTH) LOOP=C 3 CCNT INUE SXS=SZX+5.0 CALL PLOT(SXS,C. ,-3) RETURN END C ***************************** SUBROUTINE SCAL2D(G , I DM , JDM , I X,IY,GMAX,GMIN,NCONT,CMAX,CMIN,CINT) C SCAL2D SCALES THE MAP FOR PLOTTING C G(IX,IY) IS THE DATA TO BE SCALED 3F OUTSICE DIMNS. (IDM,JDM) C GMAX AND GMIN ARE THE MAX AND MIN VALUES OF G C NCONT IS THE NUMBER OF CONTOURS C CMAX AND CMIN ARE THE MAX AND MIN CONTOUR VALUES C CINT IS THE CONTOUR INTERVAL C * **4 ************************************************************** D I MENS I CN G( IDM, JDM), A(5 ),B(5) C FIND MAX & MIN OF G GMAX=-1C.CE6 GMIN=10.0E6 DC 10 1=1,IX DO 10 J=1,IY IF(ABS(G(I,J)).GT. 10.CE2C) GO TO 10 IF( G( I, J ) .GT .GMAX ) GMAX=G(I,J) IF(G(I,J).LT.GMIN) GMIN=G( I,J ) 10 CONTINUE C RANGE IS DIVIDED INTO NCONT PARTS DG=(GMAX-GMIN)/FLOAT(NCONT ) C FIND ORDER OF INTERVAL I N'T INT=ALOG10(DG) C INCASE INT IS -VE IF(DG.LT.l.O) I NT = I NT-1 DGN=DG/10.C**INT C DGN NOW LIES BETWEEN 1.0 Z 10.0 C CHOOSE THE BEST CONTOUR VALUE DATA AQ),A(2),A(3),A(4) ,A(5)/1.0,2.0,2.5,5.0 ,10.0/ TEMP=ll.C DC 20 J=l,5 B(J)=ABS(OGN-A(J) ) IF (B(J).LE.TEMP) IVALL^J IF( B(J ) .LE.TEMP ) TEMP=B(J) 20 CONTINUE CINT=A(IVALU)*10.0**INT C 0.0 MUST BE A CONTOUR ITEMP=GMIN/C INT CMIN=CINT*(ITEMP-L ) ITEMP= GMAX/CINJT CMAX=CINT*( ITEMP+1 ) RETURN END $ S I G N O F F $CCPY *SOURCE*a-.CC *SINK* Q 4 * 4 4 * 4 * * TRACKER 4 4 4 4 4 4 4 4 C C PROG PLCTS SHIP'S TRACK - GIVEN SHIP'S CC-CRCS, EVERY NFLCT-TF POSITION C IS PLOTTEC .... SET UP *NP LOT * IN STMT #9 .... C THIS PROG WRITTEN INITIALLY FCR MAX OF 7000 CATA POINTS .. C 2 = SHIP'S FCSITICNS TC BE PLCTTEC C 4 = Z-COORD FORMAT FOLLOWED BY ... C FLCT-SIZE ALCNG Y-AXIS, C NC. CF CCNTCUPS TC EE PLOTTEC IN RANGE OF Z, C X-COQRD / Y-COORD CF PLCT ORIGIN, C INCREMENTS/PLOT INCH ALONG X- 6 Y-AXES RESP. C 9 = FLCT COMMANDS O/P. C WRITTEN TO PLCT CSS PARIZGAU 197C MAG CATA : 28 FEE 1972 ROCQUE GCH UBC C CCMMON/DEEUG/FLAG LOGICAL FLAG FLAG= .TRUE. DIMENSION FMT(2C), X(7G0C), Y{7CCC) C *44*EVERY N PLCT FCSITIONS ARE PLOTTEC ... 9 N PL C T = 5 C 4 4 4 4 R E A D IN SHIP'S POSITIONS FORMAT FROM UNIT 4 REAC(4,10) FMT IC FCPMAT{2CA4) WRITE(6, 12) FMT 12 FORM AT(IX, 'SFIP"S POSITIONS CO-ORD FORMAT I S . . 1 , 2 0A4 ) C 4444READ IN PLCT PARAMETERS - INITIALISE PLCT SUBROUTINES, C NCONT NOT REQUIRED FCR THIS PPOG - SC THIS IS JUST A DUMMY READ .. CALL PLOTS REAC(4,20 ) SZY READ(4,22) NC C NT READ(4,24) XCCCR, YCCCP REAC(4,24) CX, DY READ(4,22) IX 2C FORMAT (F2C.5) 22 FORMAT! 12 ) 24 FCPMAT (2F2C .5 ) WRITE(6,3C) SZY,NCCNT,XCCCR,YCCCP,CX,OY, IX,IX 30 FORMAT(IX, 'PLOT PARAMETERS I/P ARE..'/IX, 'SIZE Y =», F1C.3,3X, + 'NC. CF CCNTCUPS IN RANGE = ' , 16 / 1X , 'X- C Y-COCRDS OF PLCT CRIGIN +=', 2F13.3/1X, 'INCREMENTS ALCNG X- S Y-AXES APE*, 2F10.3/1X, •GRI + D IS TO BE', 16, ' X », It/) C 444-4CALL YSIZE IF LARGE PLOT REQUESTED. IF(SZY.GT.1C .5 ) CALL YSI2E(29.0) I Y= IX IC IM X= IX ICM= IX JDM=IX L T H = 1 C 4444N0W READ IN Z-COORDS TO BE GRIDDED/PLOTTED. NFTS=1 4C READ(2,FMT,END=50) (X(NPTS), Y(NPTS)) NPTS=NPTS+ 1 GC TO 40 C 44 4 4 E N D F ILE READ - ASSUMED hC MCRE CATA POINTS. 5C NPTS=NPTS-l WRITE ( 6 , 5 2 ) NPTS 52 FORMAT ( IX, 'NC. CF DATA FCINTS READ IN = ' , 1 6 , * . LAST DATA PCINT:') WR11E(6,FMT) X(NPTS), Y(NFTS) C 444*MOW REFERENCE ALL SHIP CO-ORDS TC MAP CRIGIN S SCALE THEM TC PLOT-INCHES CC 69 1=1,NPTS X(I)=(X(I)->CCCP)/DX 69 Y( I )= (Y(I)-YCOCR)/DY C ****NCW PLCT AXES ... CALL AXIS(0. ,C. ,1H , - i , S2Y , 0 . ,XCCCP ,CX ) CALL AXIS(C. ,C. , IH , + 1 ,SZY , 9C. , YCCCR,CY ) C * * 4 *NO W pi_OT EVERY NPLOT-TH POSITION - SHIFT TO FIRST POSITION 'PEN UP' .. CALL FLCT(X(1 ) , Y ( 1 ),-»3 ) DO 75 K = l ,NPTS ,NPLOT 75 CALL S Y M e O L ( X ( X ) , Y ( K ) , C . C 3 5 , 2 , 9 C . , - l ) C ****THAT'S ALL - TERMINATE PLOT SUBROUTINES CALL PLOTNC WRITE(6, EC) 8C F0RMAT(//1X, • *** LOOKS LIKE A GCCD PLCT ») STCF 1 END $CCPY *SKIP * S I N K * SCOPY *SOURCE*3»-.CC +SINK* C 4 4 4 4 44 44 4 4 STATION MAG PLOTTER ********** C C PRCG PLCTS STATION MAC- CATA - CATA FORMAT COMPATIBLE WITH ATLANTIC C OCEANOGRAPHIC LABORATORY STATION MAC CATA ...... C GEEZOICIFATEWRITINGTHISQNE ... 3 MARCH 1972 ROCQUE GOH GEOPHYSICS UBC C SET I/O UMTS 8 = MAG CATA TC BE PLOTTEC (STAT ION MAG ) C 5 = CCNTRCL COMMANDS - TINE-PERICDS TO EE PLOTTEC C 9 = PLOT COMMANDS Q/P C WRITTEN PRIMARILY TO PLOT ATKINSON POINT STATION MAG - 197C IMPLICIT REAL*8(A~H,C-Z) REAL*4 XPLOT( 1CCO).YPLOT{1CCC) D I MENSICN MAG(1COO),SMAG(1CCC ),STIME(1CCC),SMIN( 1CCQ), +PX(1CCO),PY(1CCO) COMMON/DEBUG/FLAG LOGICAL FLAG FLAG = .TRUE. C ****NMAG = NO CF STATION MAG REACINC-S PER HCLR IN CNE RECORC ... NMAG= 12 C ****LFCINT = LCAC POINTER USEC FOR LOADING C/P ARRAYS .... IE READ( 5 , 2C,END=':95) PS C A Y , P ST I ME , FE D AY , FET I NE LPOINT=l 20 FORM AT(4F20.3) CALL TMINT( PSDAY , PSTI ME, FSMIN) CALL TMINT( PEDAY,PET I ME,FEMIN) WRITE(6,30 ) PSDAY,PSTI ME,PECAY,PETIME 3C FCRMAT(* YCL HAVE ASKED FCR THE FOLLOWING DATA TC BE PLCTTEC ...'/ +• START : DAY*,F6.1,« - TIME ,,F6.1,» / ENC : DAY',F6.1,« - TIME', +F6.1/' I''LL TRY TO FIND AND PLOT IT •/) C ****READ IN MAG DATA £ CHECK IF IT IS TO EE PLOTTED .... 35 ME0F = G 4C REAC(8,45,END=9CC) MDAY,MHOLR,(MAG(I), I=1,NMAG) 45 FCPMAT(2X, 13,IX, 12,12 16 ) DC 50 MM=1,NMAG SMAG (MM )=FLCAT(MAG(MM) ) SDAY = FLCAT{M DAY) SFC LR=F LCAT ( MHCUR) ST IME (MM )=(SHCUR* 100. HFLCAT ( (MM-1 )*5) CALL TM INT(SDAY,STIME(MM),SMIN( MM)) 5C CCM IME DC 51 MM = 1 , N M AG IF (PSMIN .EQ.SMIN(MM)) GO TO 6C IF( FSMIN.LT.SMIN(MM)) GO TO 98C 51 CCNTINUE WRITE(6,52) MDAY, MHCUR 52 FORMAT(* SKIPPED RECORD FCR DAY/HOUR',216,' .......•) GC TC 35 C 4***F CLND MAG DATA NEEDED - START LOADING INTC C/F A F FAYS .. 60 WRITE(fi,64) SM IN (MM ) 64 FCR MAT( • FCUND DATA TO EE PLOTTED AT SEQUENTIAL MINUTE =',F15.2) WRITE(6,66) PSMIN, PEMIN 66 FORMAT ( • COMPARES WITH START-MIN GF'.FIO^,' S END-MIN CF ,,F10.2) CO 70 K= MM,NMAG PX( LPC INT ) = SM IN (K ) PY(LPOINT)=S MAG(K) IF(PEMIN.LE.SMIN(K)) GQ TO 91 LFCINT=LPCINT+1 7C CONTINUE C *4**READ IN MAGS S KEEP LOADING TILL END OF PERIOC KAN TED IS SENSE C NCTE LCAC POINTER IS REACY FOR NEXT LOAD 77 READ(8,45,END=SC0) MOAY,MHCUR»(NAG( I) , I=1,NNAC) CO 80 J= 1, NMAC- SNA G { J)=FLCAT(MAG(J ) ) SDAY=FLOAT(MCAY) SHOLR=FLOAT(NHCUR) ST IME (J ) = ( S FOUR* ICC. ) •+ (FLOAT! ( J - l)*5) ) CALL TN1NT(SCAY,STIME(J ) , SM IN (J ) ) P X ( L PO I N T ) = S N. I N ( J) PY(LPOINT)=SMAG(J) IF( FENIN.LE.SNIN(J) ) GO TO 91 LFCINT=LFCINT+1 6C CONTINUE GO TO 77 C ****ENUFF DATA LCACEC 91 LPCINT=LPOINT-1 C CHECK FCR ZERO 1̂ AGS - IF ZERC, SET TO MAG VALUE CLOSEST TC IT C THIS ISN'T THE MOST SATISFACTORY OF SETTING ZERO READINGS, BUT DC 92 I=1,LF0INT IF(PY{ I ).GT.C.) GC TC 92 IF(I.EQ.l) PY{I )=PY(1 + 1 ) IF(I.GT . l ) FY ! I ) = PY ( 1-1 ) 92 WPITE(6,94) PX(I) , PY{ I) 94 FORM A T (/ ' MAG.LE.ZERO AT SKIN 0F',F1C.2,« - SO SET TC», F 1 C 2 ) 92 CCNTINUE WRITE(6,95) PX(1) , PX (I PC I NT ) , FSM IN , PEN, IN 95 FORMAT!/• FIRST £ LAST DATA FUNIS LOACEC ARE ...«/» FIRST SMIN +F10.2,' - LAST SMIN = ',F1C . 2, ' - ARE THEY REQUESTED POINTS WHICH + E ' , 2 F15 . 2 ) C 4***READY TC PLOT - SET LP PLCT 8CUNDAPIES .... CALL CERMAX!PX,LPOINT,PXNAX) CALL DERMIN(PX,LPCINT,PXMIN) CALL DERNAX!PY,LPCINT,FYNAX) CALL DER MIN(P Y,LPC I NT,PYNIN) CY = 50 .0 DX = 30 .0 C *4**FIND NICELY RCUNDED CC-CRD ECUNCARIES .... YOR= IFLQAT(I DINT!PYMIN/DY ) ) )*DY XCP=(FLCAT(ICINT(PXMIN/CX)))*CX WRITE(6,1C2) XCR, YCF 1C2 FORMA T ( ' PLCT WILL BE ORIGINEC AT X =',F1C2,' - Y =',FIC2) YMAX=((FLOAT(ID INT!PYMAX/CY ) ) )*DY ) +DY XMAX=( (FLCAT(ICINT(PXNAX/CX) ) )*CX) + CX SZ>=(XMAX-XCR)/CX SZY=(YMAX-YOR )/DY IF! SZY.GT.1C . ) CALL YSIZE(29.0) WRITE(6,1C8) SZX, SZY 108 FORMAT(' PLOT SIZES WILL BE - X =',F10.2,' - Y =',F1G.2) C ****SCALE DATA TC FLOT INCHES .... DO 115 K=1,LPCINT XPLOT(K) = (PX(K)-XOR) /DX 115 YFLCT!K )=(PY(K)-YGR)/CY C ****AND WE START TC PLCT .... CALL PLOTS CALL AX IS ( C C . , ' STATION MAG (GAMMAS) ' , +19 ,SZ Y , 9 C . , YGR, DY ) CALL AX IS(0 .,0 .,'TIME - M INUTES ' ,-14,SZX,C.» XOR,D X) CAL L LINE(XFLCT ,YPLOT,LPCINT, + 1) XSYM= SZX + C .5 CALL |VUNBER(XSYM,0.5,C.14,PSDAY,9Q.,-1) CALL WHERE( X , Y ) X=XSYM Y=Y+0.84 CALL NUNBER(X,Y,0.14,PSTINE,90.,-1) X=XSYM CALL SYMBOL!X,Y,0. 14, « TO »,9C.,8) CALL WHEPE(X,Y) >=XSYN Y=Y+0.42 CALL NUMBER(X,Y,0.14,PEDAY,9C. ,-1) CALL WHERE(X.Y) X=XSYM Y=Y+C.£4 CALL NUMBER(X,Y,0.14,PETI ME,9C. ,-1) C ****RE-CRIGIN FLCT FOR NEXT CNE .... XNEW=SZX+1C. 0 CALL PLOT(XNEW,C. ,-3) WRITE(6,120) PSDAY.PSTIME,PEDAY » PET I ME 12C FORMAT!/' PLCT GENERATEC FCR PEP ICC ',2 F 10 . 2 » ' TO *,2F1C.2///) GO TO 16 C 4***THESE ARE THE EXITS ..... 9C0 WRITE! 6, 903 ) 9C2 FORMAT!/' INSUFFICIENT MAG CATA - FLCT NCT GEN E P AT E C • ) STOP 9 980 WRITE(6,983) 983 FORMAT(/' MAG DATA HAS HCLES - FRCG CANNOT PLOT IT') STOP 7 995 WRITE(6,997) 997 FCRM A T( ' ENCFILE ON UNIT 5 - NC MO FE PLOTTING REQUESTED') CALL PLOTND STGP 1 END SUBROUTINE TMINT(DAY,TI ME , SMIN) IMPLICIT REAL*8(A-H,0-Z ) IC DMIN=DAY*1440. IF!TIME.NE.C. ) GO TC 30 HMIN=0. XN IN=0 . GC TO 40 3C IHRSMDINT (TIME/ICO. ) HM IN = IHRS*6Q. JHRS=IHRS*1CG HR S J=DF LOAT(JHRS) XMIN=TIME-HRSJ 40 SMIN=DNIN+HNIN+XMIN RE TLRN END C 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 * * 4 * * 4 * 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 * * * * * * * * * * 4 4 4 4 * 4 4 4 4 SUBROUTINE CEPMAX(X,N,DM AX ) IMFLICIT REAL*8<A-H ,C-Z) DIMENSION X(N) DNAX=-10.E30 DC 20 1=1,N IF (X (I ).GT. CMAX) DMAX = X! I ) 20 CONTINUE WPITE(6,35) CMAX 35 FORMAT ( ' MAXIMUM VALUE FCLNC =',F15.2) RETURN END C **4*4*4***********************4***4 4 444**4**4**4*4 4 444 444444 SUBROUTINE CERMIN(X,N,0MIN) IMPLICIT REAL*8(A-H,0-Z ) DIMENSION XtN) DMIN=+10.E3C CO 30 1=1, N IF(X { I ) .LT .CHIN) C M I N= XII) 3C CONTINUE WRITE(6,37) DM IN 37 FORMAT{• MINIMUM VALUE FCUNO =»,F15.2) RETURN END $COPY *SKIP *SINK* $CQPY *SGURCE*5)-.CC *SINK* C 4 4 4 * 4 * ONEDEE PLOTTER 4*4=4=** C C PRCG PLOTS NAG CATA IN TINE SERIES - ON E-CIN EMSIONALLY .. C DATA MUST BE ORGANISED IN LINES WITH L IN E# S # CF POINTS PRECEDING EACH C LINE DATA ... C 8 = NAG CATA TC EE PLOTTEC C 9 = PLCT COMMANDS C/P C WRITTEN PRIMARILY TO PLOT BEAUFORT SEA/NACKENZIE BAY NAG CATA C WRIT TEN INAHURRY 2 MARCH 1972 ROCQUE GOH GEOPHYSICS UBC DIMENSION SNINUOOO), ZNAG(ICCO), DUNNY(ICCO) COMMON/DEBUG/F LAG LOGICAL FLAG FLAG = .TRUE. IFLAG=C C ****RE^D IN CONTROLS CARDS IC KNOW WHICH LINE IS TC BE PLCTTEC ... 18 READ(5 , 2 G,EN 0=995) PLINE 20 FORMAT(F2C.3) C DON'T READ IN ANY MAG DATA IF IFLAOC ... IF{ IFLAG .GT .0 ) GO TO 2 7 C ....READ IN DATA AND CHECK IF IT IS TC BE PLCTTEO ... MEOF=0 22 REAC(8,25,END=3C) LLINE, NPTS 25 FORM A T(IX,16 , 1 X , 16 ) QLINE=FLOAT(LLINE) C ....CHECK IF LINE IN HAND IS TO BE PLOTTED ... 27 IFlFLINE.EC.CLINE) GO TO 40 IF(FLINE.LT.QLINE) GC TC 3 5 C ....DATA NOT TO BE PLOTTED - SKIP AND GET NEXT SET .... I F L A G = 0 NECF=0 READ(8,2£,END=991) (DLNMY(I), 1 = 1,NPTS) 28 FORMAT(F10.2) WRITE(6,26) CL IN E 26 FORMAT!' LINE #',F10.2,' SKIPPED CVER ') GO TO 22 30 NECF=NECF-4l IFtNECF.GT.1) GO TO 33 GO TO 22 C 44**TWC ENOFILES READ - NO MORE MAG CATA TO PLOT .. 33 WRITE(6,34) PLINE 34 FORMAT( ' LAST LINE PPCCESSEC WAS',F10.2,' - TWC EOFS CN LNIT 8') CALL PLOTND STCF 5 C * 4 4*LINE TO BE PLOTTED NCT FCUNC - GET NEXT CCNTRCL CARC ... 35 WRITE(6,26) PLINE 36 FORMAT!/' LINE #',F10.2,' NOT FOUND - NOT PLOTTED') IFLAG=1 MEOF=0 GO TO 18 C ****FCLND LINE TC EE PLOTTED - FEAE IN LINE DATA ... 4C MEOF=C IFL A G=0 REAL! 8,50, ENC=991 ) (S M IN (K ), 1 MA C- I K ), K=1,NPTS) 5C FCRNAT(12X,F11.2,55X,F7.1,16X ) WRITE(6,53) PLINE 53 FCRNAT( ' FLCT Z AT A FOR LINE UNF10.2,' RE AC IN - LAST DATA POINT') WRITE(6,50) SMINMNPTS), ZMAG(NPTS) C * * < * SE T UP PLOT PARAMETERS CY=50. CX = 30 . C ****FIND MAX/MIN VALUES CF SPIN 8 ZMAG .... CALL DERMIN(SNIN,NPTS, SSMIN) CALL OERNAX(SMIN,NPTS,ESM IN ) CALL DERNIN(ZMAG ,NPTS ,SZMAG ) CALL DERMAX(ZMAG,NPTS,8ZMAG) C 4***FIND HUNDRED-GAMMA VALUE JUST BELCW LCWEST ZMAG .. YCR = (FLCAT(INT(SZMAG/CY) ) )*CY C *«**FIND PLOT-INCH JUST EELCW LCWEST SMIN .... XGR= ( FLOAT ( INT { S SM IN AD X ) ) ) *D X WPITE(6,55) XCR, YOR 55 FORMAT ( • PLCT WILL BE CRIGINEC AT X =',F1G.2,« - Y =',F1C2) C ****FIND HUNDRED-GAMMA VALUE JUST AEOVE HIGHEST MAG ... YMAX = ( (FLCAT ( INT IB ZMAG/CY ) ) )=*DY) +DY SZY={YMAX-YCR)/CY IF(SZY.GT.1C.) CALL YSIZE(29.C) C 4 * 4«FiND DAY JUST HIGHER THAN THE LARGEST SMIN VALUE .. XNAX=( (FLOAT(INT(BSM 1N/CX ) ) )*CX )+DX SZX= (XM.AX-XCR)/DX WRITE(6,56) XMAX, YMAX 56 FCPNAT(' MAXIMUM CO-ORCS ARE X = ',F1C2,' : Y =',F10.2) WRITEU.57) SZX, SZY 57 FORMAT( ' PLCT SIZES WILL EE - X-AXIS = ',F1C2,' - Y-AXIS =',F10.2) C ****SCALE DATA . . . CC 7C M=1,NPTS SMIN(M)=(SNIN(M)-XOR)/OX 7C ZMAG(M )= (ZNAG(M )-YOR )/DY C * * * * S 1 A R T PLOTTING - AXES FIRST, POINTS NEXT ... CALL PLOTS CALL AXIS(C.,C., 'MARINE MAG - GAMMAS' ,+ 19,SZY,SC. ,YCR,DY) CALL AX IS (C. ,0. ,'TIME - MINUTES' ,-14,SZX,C.,X0R»DX) CALL LINE(SMIN,ZMAG ,NPTS , + 1) C ****PE-ORIGIN PLCT AXIS FCP NEXT PLOT ... XNEW=SZX+5 .0 CALL FLCT(XNEW ,0. ,-3) C ****GET NEXT CCNTPOL CARD FCR NEXT FLCT .. WRITE(6,78) PL INE 78 FCF M AT ( ' LINE 3',F10.2,' PLOTTED ' ) GO TO 18 C *>M*UNEXPECTEC ENCFILE ON MAG CATA TO BE PLOTTED ... 991 WRITE(6 ,992) <92 FORM AT( ' LNEXFECTEC ENCFILE ENCOUNTERED ON UNIT 8 - MAG CATA * ) STOP 9 C *<**NC MORE LINES TO BE PLOTTED ... 995 WRITE(6,996 ) PL INE S96 FOR MA T ( ' LAST LINE PLOTTED',F 10.2,' - NORMAL TERNIfsATICN' ) CALL PLOTND STOP 1 ENC SUBROUTINE CEFMAX(X »N , C N A X ) DIMENSION X(N) CMAX=-10.E3C CC 20 1=1,N IF(X(I).GT.CMAX) DMAX=X(I) 20 CONTINUE WPITE(6,35) DMAX 35 FORMAT I • MAXIMUM VALUE FCUNC =• ,F15.2) RETURN END SUBROUTINE CEPNIN(X,N,CMIN) DIMENSION X(N) CM IN = + 10 .E3C DC 30 I=1,N IF(XU).LT.CMIN) DMIN = X(I) 3C CONTINUE WRITE(6,37) CMIN 37 F OP MA T ( ' MINIMUM VALUE FCUNC =« fF15.3) RE TURN ENC $CCFY -A *PUNCF* SSIGNOFF


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