基于ECMWF模型改正InSAR大气延迟误差的可靠性实验

Test on InSAR Atmospheric Delay Correction Using ECMWF Model

大气延迟是影响InSAR观测数据质量的最主要因素之一.然而,这一难题一直没有很好的解决办法.近年来,采用气象模型改正InSAR大气延迟误差是一个热门的研究方向,不过其有效性和可推广性还需要一些实验来检验.本文采用青藏高原中部的InSAR数据检验基于ECMWF模型改正InSAR大气延迟误差的有效性.结果显示本实验采用的8幅干涉图中只有3幅在改正后方差减小,而所有数据的平均方差比改正之前更大,证明该模型无法很好地改正该地区InSAR的大气延迟误差.鉴于目前尚无可靠的方法判断何时何地ECMWF模型对InSAR大气延迟误差有改进作用,建议谨慎采用该模型改正大气延迟误差.

Atmospheric delay is one of the most significant errors in InSAR.However,efficient methods have not been found to correct such artifact yet.Weather models have been widely used to correct InSAR atmospheric delay errors in recent years,but more tests are required to demonstrate the efficiency of this method.The ECMWF model was used to correct InSAR atmospheric delay errors in central Tibet.The results indicate that only 3 out of 8 interferograms have been improved with smaller variance after correction,and the average variance is even bigger than that before correction.It means that with the ECMWF model,reliable improvements cannot be made in our study area.Considering that there is no reliable approach to test when and where the ECMWF model can improve the quality of InSAR data,it is suggested that the users should be more careful about using this model for InSAR correction.