V.H.F. RADIO AURORA: SIMULTANEOUS OBSERVATION OF AURORAL IONIZATION BY TWO SEPARATED RADARS

Abstract

Data from a Canadian v.h.f. radar network which operated during the IGY were analyzed to determine the aspect sensitivity of 48-MHz radio aurora. Two radars of this network simultaneously viewed a region of high-visual and radio-auroral activity. This paper is concerned with echoes which were obtained over a two-year period from auroral ionization simultaneously observed by these radars. The general properties of these simultaneous echoes were determined and are compared, where possible, with the corresponding properties of the overall set of echoes seen by each radar when looking independently at the same region. This comparison indicates that the mechanism responsible for simultaneous echoes is very probably the same as that which is responsible for the majority of radar echoes seen individually by the two radars. The spatial and temporal correlation between the simultaneous echoes and visual aurora is presented. The average aspect sensitivity of these echoes (48 MHz), which were obtained from simultaneous observations at off-perpendicular angles near 5° and near 20°, was found to be 1 dB per degree.