基于DEM与GACOS的InSAR同震形变场大气误差校正北大核心CSCD

从全球地震频发地区选取多次地震事件,以精河地震为例研究基于DEM进行大气误差校正时拟合区选取方法;然后分别基于DEM和GACOS数据对同震形变场进行大气相位延迟改正以分析其校正精度及适用性。结果表明,扣除主要同震形变区域后的相位-高程相关系数大于0.4时,必须对获取的形变场进行大气误差校正,校正后噪声可下降约1~4 cm;相关系数为0.4~0.8时,可通过两种方法相互验证以校正精度;相关系数大于0.8时,可以只使用DEM拟合大气误差分布函数进行校正。基于GACOS进行大气误差校正具有普适性,用于大气噪声较为严重且与地形不相关的平原地区可取得较好效果。

Atmospheric Error Correction of InSAR Co-Seismic Deformation Based on DEM and GACOS

We select multiple seismic events from seismic-prone regions in the world. Taking Jinghe earthquake as an example, we study the selection method of fitting region for atmospheric error correction based on DEM. Then, to analyze the accuracy and applicability of the correction, we carry out the atmospheric phase delay correction of the co-seismic deformation field based on DEM and GACOS data. The results show that when the phase-elevation correlation coefficient after deducting the main co-seismic deformation region is greater than 0.4, the atmospheric error correction must be made to the obtained deformation field, and the noise can be reduced by 1-4 cm after correction. When the correlation coefficient is 0.4-0.8, the correction accuracy can be verified by the two methods. When the correlation coefficient is greater than 0.8, only DEM fitting atmospheric error distribution function can be used for correction. The atmospheric error correction based on GACOS is universal and can achieve better results in plain areas where atmospheric noise is more serious and is not correlated with terrain.