A New Baseline Estimation Approach Based on the Periodic Interferometric Phase

Baseline is a key parameter in the principle of synthetic aperture radar interferometry (InSAR). It plays a highly important role in the geometric conversion from interferometric phase to terrain altitude. Conventional baseline estimation is calculated by orbit parameters. However, due to the influence of atmospheric resistance and universal gravitation, orbit parameters have uncertainty in a certain extent, which arouses the decrease of baseline accuracy directly. In this paper, baseline evaluation, which is unconnected with orbit parameters, is based on the periodic interferometric phase. Firstly the relationship between baseline and the interferometric phase period is analyzed in detail. Based on this, a new kind of baseline estimation approach is proposed. Furthermore the problem about selection of the given terrain is discussed. Finally the approach is validated by the example using the ERS-2 data.