IONOSPHERE PROBING WITH A HIGH FREQUENCY SURFACE WAVE RADAR

This paper describes how the ionosphere re∞ected echoes observed by a high frequency surface wave radar (HFSWR) can be processed to extract information regarding the ionosphere sporadic E (Es) and F2 layers. It is shown that the range/time spectrum contains the data to estimate the occurring time and virtual heights of both the still and drifting Es layer clouds. In addition, for the drifting Es the data can be processed to extract the time-varying ranges and estimate virtual heights, horizontal drifting speeds. Information regarding the F2 layer such as the time-varying virtual heights can also be extracted. The time-frequency distributions (TFD) of the Es and F2 layer echoes calculated after the range migration compensation can be used to extract the intrinsic Doppler patterns. This is further used to obtain information on the internal non-uniform structures and disturbances such as the travelling ionospheric disturbances (TID) that are due to the acoustic gravity waves (AGW). Processing results of echo data collected by the portable HFSWR system named OSMAR-S demonstrate the validness of the above methods.