Improved DORIS Baseline Estimation in InSAR

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.