Tracking the aurora by a multifrequency HF backscatter sounder

Abstract

A comparison of simultaneous optical and radio auroral data obtained during 12 days in December, 1964, shows conclusively that the radio wave scattering belt includes the visual auroral belt. The optical data were obtained with the Alaskan network of all-sky-cameras located between 65 and 80° north geomagnetic latitude. With the exception of vertical incidence, meteor, groundscatter, and slant F (polar spur) traces, all of the recorded backscatter traces from the north were scaled indiscriminately for slant range. The excellent agreement that resulted leads us to conclude that the majority of the HF and low VHF backscatter echoes observed at high latitudes are auroral echoes in the strict sense of the term. In the records shown the auroral belt was tracked from 65 to above 80°N geomagnetic latitude. It is concluded that the multifrequency HF backscatter sounder makes year-round observations of the auroral belt possible.