Аннотации:
A simple indicator has been introduced to detect weak mid-latitude TIDs in ionograms. This indicator is based on the differential rotation of the cusp part of the trace of the F layer. This approach turned out to be much simpler than the analysis and isolation of various additional traces in the form of cusps and hooks. Such an approach turned out to be more capable for highly noisy ionograms. Processing of 3-month data allowed us to detect clear daily-seasonal variations in the intensity of SSTIDs in autumn observations.