InSAR观测值大气改正方法的研究进展

介绍了国际上InSAR观测值大气改正方法最新的研究进展，应用实例证明了由于大气（尤其是水汽）的影响，传统的InSAR形变量的监测精度往往只能限制在cm级；而利用GPS数据，通过基于地形的GPS扰动模型（GTTM），大幅度削弱了大气对干涉影像的影响，并成功地探测出了美国洛杉矾地区明显的季节性地表形变，形变量精度可提高到5mm左右。通过与GPS／MODIS集成大气改正模型的结果的比较表明，GTTM和GPS／MODIS两种大气改正模型在削弱InSAR观测值大气水汽影响方面具有很强的互补性。

Atmospheric Correction Models for InSAR Measurements

A brief review of InSAR atmospheric correction approaches,which have been developed to reduce atmospheric effects(particularly water vapour effects) from SAR interferograms in the last decade,is given.Emphasis is given to GPS topography-dependent turbulence model(GTTM) developed at University College London.Examples over the Los Angeles region reveals that,without InSAR atmospheric correction,the RMS differences between GPS-derived and InSAR-derived range changes in the line of sight(LOS) direction were 1.0 cm.After applying the GTTM,the RMS differences decreased to 0.5 cm,suggesting that the GTTM successfully reduced atmospheric water vapour effects on interferograms.A comparison between the GTTM and the GPS/MODIS integrated water vapour correction model shows that the GTTM and GPS/MODIS integrated models are complementary when correcting InSAR measurements.