RESEARCH ON THE LINEAR AND NONLINEAR METHODS OF CORRECTING BASELINE ERRORS ON SAR INTERFEROGRAMS

摘要

In this paper, the precise orbit and the coarse orbit are both used to compare the characteristics of the baseline errros on interferograms. To eliminate the fringes caused by baseline errors, a linear algorithm which is done on interferograms and a nonlinear algorithm which is performed on phase-unwrapped maps are both used. The unwrapped phase values are decreased greatly after baseline errors are eliminated using bilinear method. The results show that the standard deviation (STD) is decreased from 10.9 radians to 3.1 radians. In nonlinear method, a quadratic function is used to fit the surface of the phase-unwrapped map, then the fitted surface is subtracted. STD is decreased from 10.9 radians to 2.8 radians. The results show that the nonlinear method is a little effective than the linear one.