DIGISONDE OBSERVATION OF NIGHT TIME SPREAD-F AT HAINAN ISLAND(Abstract)

Observation of night time spread-F was performed by means of DGS-256 atHainan island.Owing to the multi-parametric measurement ability of DGS-256,themulti-trace structure of range spread-F was found on both the amplitude ionogram andstatus ionogram.This structure consists of a main trace,echoes reflected vertically fromordinary ionosphere,and one or several satellite traces,off-vertical echoes reflected from disturbing ionosphere.