UBC Theses and Dissertations
Pulsar reception at 22 MHZ Dewdney, P.
An attempt is made to receive pulsar signals at a frequency (22 MHz) lower than they have been received before. The problem of high galactic background radiation is the dominant one. The receiver used optimizes the ratio of signal to sky background noise. The technique uses the property that pulsar signals are dispersed by intervening electrons. Using the known dispersion relation it is possible to predict the phase of the pulsar signal at one frequency (22 MHz) if it is known at another frequency (150 MHz). The receiver then tracks the pulse in frequency vs. time with a bandwidth which is small enough to match the instaneous bandwidth of the signal. Although it was found that pulsar signals from CP 1919 are still too weak to be received on such a system, an upper limit to their strength was obtained by measuring its sensitivity. At the time of observation (August, 1969) the signal strength at 22 MHz, averaged over 2600 pulses, was less than 1.0 x 10⁻²⁶ joules per m² of capture cross-section per unit bandwidth.
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