A Study of "Spread?F" Ionospheric Echoes at Night at Brisbane. II. Interpretation of Range Spreading

Abstract

A review is given of various hypotheses which might explain the behaviour of "range multiplets", in which satellite echoes accompany the F2. echo at frequencies well below the critical penetration frequency. It is shown that these cannot arise from stratification of the layer. Some few may be due to reflection from the F layer of waves previously scattered upwards by an Es irregularity. The great majority, however, appear to originate in reflections from irregularities in the F layer itself. This is confirmed by the directional observations, multiple-hop echo records, correlations between separated stations, and the usual shape of the range-time curves, as described in Part I