The fluctuations of atmospheric water vapor content in space and time, which will lead to an uncertainty propagation delay of the radar signal, is one of the main factors affecting the accuracy of InSAR. As a new sounding instrument, the foundation GPS can provide in real time continuous, all-weather, high precision precipitation water vapor values, which can be used for atmospheric correction of InSAR, nevertheless, it needs interpolation in space for using GPS water vapor observations to correct atmospheric delay in InSAR. Inappropriate interpolation methods will lead to distortion of the spatial distribution of water vapor. In conventional interpolation methods, such as inverse distance weighted (IDW) interpolation and Kriging, due to the failure to take account of the influence of topography on atmospheric delay, the interpolation results are not ideal. Therefore, this paper proposes an improved Kriging (IKriging) method, which can take into account the impact of elevation and distance on the atmospheric interpolation. The experimental results in Hong Kong show that IKriging has obvious advantages over the Kriging method. This method can be further promoted to establish the multi-factors fitting interpolation model.
[1] Massonnet D,Feigl K L.Radar interferometry and its application to changes in the earth's surface[J].Reviews of Geophysics,1998,36(4):441-500.[2] Goldstein R M,Engelhardt H,Kamb B,et al.Satellite radar interferometry for monitoring ice sheet motion:Application to an antarctic ice stream[J].Science,1993,262(5139):1525-1530.[3] 张勤,赵超英,丁晓利,等.利用InSAR与GPS研究西安现今地面沉降与地裂缝时空演化特征[J].地球物理学报,2009,52(5):1214-1222. Zhang Q,Zhao C Y,Ding X L,et al.Research on recent characteristics of spatio-temporal evolution and mechanism of Xi'an land subsidence and ground fissure by using GPS and InSAR techniques[J].Chinese Journal of Geophysics,2009,52(5):1214-1222.[4] Zhao C Y,Zhang Q,Ding X L,et al.Monitoring of land subsidence and ground fissures in Xi'an,China 2005-2006:Mapped by SAR interferometry[J].Environmental Geology,2009,58(7):1533-1540.[5] Zebker H,Rosen P,Hensley S.Atmospheric effects in interferometric synthetic aperture radar surface deformation and topographic maps[J].J Geophys Res,1997,2(B4):7547-7563.[6] Goldstein R.Atmospheric limitations to repeat-track radar interferometry[J].Geophysical Research Letters,1995,22(18):2517-2520.[7] Hanssen R F,Weckwerth T M,Zebker H A,et al.High-resolution water vapor mapping from interferometric radar measurements[J].Science,1999,283(5406):1297-1299.[8] Li Z H.Correction of atmospheric water vapour effects on repeatopass SAR interferometry using GPS,MODIS and MERIS data[D].London:University College London,2005.[9] 张双成.地基GPS遥感水汽空间分布技术与应用[D].武汉:武汉大学,2009. Zhang S C.Research and application of remote sensing water vapor using ground_based GPS/Met[D].Wuhan:Wuhan University,2009.[10] Gendt G,Dick G,Reigber C,et al.Demonstration of NRT GPS water vapor monitoring for numerical weather prediction in germany[J].Journal of the Meteorological Society of Japan,2004,82(1B):361-370.[11] Janssen V,Ge L L,Rizos C.Tropospheric corrections to SAR interferometry from GPS observations[EB/OL].http://eprints.utas.edu.au/477/1/janssen_et_al_GPS_Solns_2004.pdf.[12] Matheron G.Principles of geostatistics[J].Economic Geology,1963,58(8):1246-1266.[13] 王正权.地统计学及在生态学中的应用[M].北京:科学出版社,1999. Wang Z Q.Geostatistics and its application in ecology[M].Beijing:Science Press,1999.[14] Song X G,Li D R,Liao M S.Reproduction of InSAR atmospheric signal using GPS data based on topography-dependent and turbulent mixing model[C]//Proceedings of the Dragon Programme Final Results,2008.[15] Paola Ballatore.Synthetic aperture radar interferometry:Separation of atmospheric artifacts from effects due to the topography and the terrain displacements[J].Earth Planets Space,2006,58:927-935.[16] Fayaz O.Modeling water vapor using GPS with application to mitigating InSAR atmospheric distortions[D].Stanford:Stanford University,2006.
2013, Vol. 25 
