Abstract: Satellite altimetry has developed into a mature marine observation technique. But the precision of observation in inland waters needs to be improved, the key of which is to eliminate the effects of land pollution in radar echo. On the basis of the coastal waveform decontamination technology, we propose an improved waveform retracking algorithm for the characteristics of inland waters to eliminate the abnormal peaks caused by land pollution in altimeter waveform. Subsequently, the decontaminated waveform is used for retracking correction to improve the precision of satellite altimetry in inland waters. The measured water level data of several lakes in Qinghai-Tibet Plateau is used for precision testing. The experimental results show that the waveform decontamination technology can eliminate the abnormal peaks in the offshore area, then retrackers are used for the corrected waveform, and the average precision reaches 15.8 centimeter, which is 14% and 27% higher than the accuracy of ICE-1 algorithm and thresholoding method. The results demonstrate that the algorithm can effectively detect and eliminate the abnormal peak of radar waveform and improve the observation accuracy of altimetry data in inland waters.

Key words: satellite altimetry, inland lake, waveform decontamination technology, waveform retracking algorithm, abnormal peak of radar waveform