Forward Scatter of Radio Signals via Meteor Trails and Short-lived Solar Radio Bursts

Abstract

IN 1948 Allen1 discussed the reflexions of very high frequency radio waves from meteoric ionization, and recently Thompson2 has reported on meteor scatter bursts as recorded with a sweep frequency receiver. Similar observations have been made in Canada by a spectrum radiometer at the National Research Council's Radio Observatory in Algonquin Park, Ontario. The system is one in which twenty receivers having band-widths of 3 Mc./s. (now being changed to 1 Mc./s.) are spaced 5 Mc./s. apart in the frequency-range of 20–120 Mc./s., and the receiver outputs are commutated at a rate of 100 times per second. Since the input of the system is ‘wide open’ and the scanning rate is fast with respect to events having durations greater than 0.1 sec., the system has 100 per cent interception probability for such events. The display of the frequency-time domain of the bursts on an intensity modulated cathode ray tube is photographed on moving 35 mm. film. The output of the N.R.C. 10.7-cm. solar patrol radiometer is also recorded on the same film and appears in the illustrations as a horizontal line at the bottom of each photograph. This spectrum radiometer was designed to observe fine structure in solar radio emissions at metre wave-lengths. It has been operating since March 1961.