利用卫星测高技术研究地面沉降的初步探讨

基于雷达波卫星测高技术,通过数据处理获取华北平原和华东地区的地面沉降数据;优化地球物理参数和环境改正数,利用高精度SRTM模型进行地形坡度改正,通过改进的阈值算法提高测高数据的观测精度。将获取的地面沉降速率与GNSS基准站观测结果进行比较,偏差为-3.4±9.1 mm/a,相关性为0.88。采用阈值法和改进阈值法进行波形重跟踪改正的偏差分别为-3.2±5.5 mm/a和-2.9±4.1 mm/a,相关系数分别为0.94和0.97。实验结果表明,卫星测高可应用于地面沉降监测研究,尤其在缺少GNSS或传统水准监测数据的偏远地区的地面沉降监测中具有重要的研究价值。

Preliminary Research on Monitoring Land Subsidence Using the Satellite Altimetry Technology

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.