InSAR中DORIS基线估计方法的改进

Improved DORIS Baseline Estimation in InSAR

雷达干涉测量中基线估计精度直接影响到合成孔径雷达干涉测量(InSAR)的精度.针对DORIS(the delft object-oriented radar interferometric software)软件采用的基线估计方法,在考虑地球参考椭球半径在不同纬度地区的差异时,分析了基线估计方法的差异,提出相应的改进方法,对干涉影像不同扫描行的基线进行了多参数-多项式拟合,最后使用德国波恩地区的数据进行验证.结果表明:当考虑参考椭球半径在不同纬度差异时,能够显著提高基线估计的精度;而对基线的拟合则可以提高基线估计的速度.

The accuracy of the baseline estimation has direct influences on the accuracy of the follow-up steps in InSAR（Interferometric Synthetic Aperture Radar）.Some existent drawbacks of DORIS（the delft object-oriented radar interferometric software） were brought forward.In fact,the orbit plane of a satellite is not perpendicular to the Earth＇s equatorial plane,causing that ellipsoid radius is not consistent along the corresponding scan line.Differences between them were quantified and the baseline estimation was fitted by a multi-variable polynomial model with the row number,column number and height at the same time.The steps for estimating the baseline at a more accurate level were proposed in the end.Datasets of ERS-1 acquired in Bonn,Germany were utilized to validate this improvement.The results indicate that the time-complexity of baseline estimation is highly improved when using a polynomial fitting model.The RMS error has been reduced from 18.1 637 m to 12.340 9 m.It should be concluded that the accuracy of baseline estimation can be improved when considering these discrepancies.