将大气相位延迟对干涉图的影响分为3个主要分量,分别采用网络法进行解算和消除。以西藏崩错地区为实验区,利用2007-2010年期间20景ENVISAT ASAR数据对该方法进行验证,并采用一维协方差函数分别对校正前后的大气延迟误差进行估计。结果显示,协方差函数中平均方差从原来的3.1mm2降到0.6mm^2,降低了80%;e-folding波长从原来的1.5km减低到0.21km,减低了86%,说明网络法可以有效地校正干涉图中的大气相位延迟误差。
As a consequence of variability in water vapor content in the atmosphere,phase artifacts in interferometric synthetic aperture radar(InSAR)images(which are caused by path delays as the radar signal propagates through the stratified and turbulent atmosphere and ionosphere),frequently degrade the interpretability of the phase and correlation signatures of terrain.The effect of atmospheric delay consists of three parts.In this paper,the three phase delays are calculated using network methodology respectively.It is applied to 20 scenes of ENVISAT(ASAR)images from 2007 to 2010over the Bengco zone of Tibet.The 1-D covariance function is used to estimate atmosphere artifacts.The experimental results suggest that after atmospheric effects are mitigated,the mean variance of the exponential function of the interferograms is reduced from 3.1mm2 to 0.6mm^2,and the average e-folding wavelength is reduced from 1.5km to 0.21 km,which means the APS correction has reduced the mean amplitude and wavelength of the covariance by about 80% and 86%,respectively.