An improved inverse distance weighted interpolation method for InSAR tropospheric delay error corrections

InSAR observation accuracy is greatly affected by the tropospheric delay error. The algorithm using GPS-derived tropospheric delay to correct InSAR tropospheric delay error is an effective method. The GPS-derived tropospheric delays have to be interpolated in order to correct the InSAR result on a pixel-by-pixel basis. For the conventional inverse distance weighted interpolation (IDW), the effect of height on tropospheric delay has not been fully considered. Therefore, an impact factor is designed for the IDW, this is called as improved IDW (IIDW). The experimental results from 22 GPS stations over SCIGN show that, compared with the IDW method, the IIDW method can improve the absolute mean error and standard deviation by 25% and 55%, respectively.