Abstract：We obtain the land subsidence rate of north China plain and east China through data processing, based on the radar altimetry technology. The geophysical parameters and environmental corrections are optimized in the study. We use the high-precision SRTM model to correct the slope of the terrain, then use the improved threshold algorithm to improve the observation accuracy of the altimetry data. The results show that, comparing the vertical motion rate derived from satellite data with those calculated by GNSS reference station data, that the deviation is -3.4±9.1 mm/a and the correlation coefficient is 0.88. With the threshold (TR) and modified threshold retracking method (MTR), the deviation decreases to -3.2±5.5 mm/a and -2.9±4.1 mm/a, and the correlation coefficient rises to 0.94 and 0.97 respectively. The experimental results show that the satellite altimetry can be applied in land surface subsidence monitoring research, particularly in uninhabited remote areas where GNSS and traditional level of monitoring data are absent.
