SEARCHING OF OPTICAL EFFECTS INDUCED BY IONOSPHERIC HF HEATING

Optical effects in the ionosphere induced by high frequency heating are very weak. Maximum signal amplitude caused by Tromso HF heater was about 100 Rayleighs in 6300A emission, and usually artificial aurora is about 1-10 Rayleighs only. Especially difficult is a detection of heating effect in a presence of bright, high spatially and temporally dynamic natural aurora (10-50 kilo Rayleighs). We discuss different methods of image processing and searching of weak periodical signal using a prior information. Examples of applying those methods for different model noisy TV frames with addition of a small heating signal are presented. We also demonstrate some initial results of Spitsberben heating facility optical signal detecting.