Validation of method for estimating interferometric phase offset without the use of ground control points

This paper analyses the use of an algorithm to estimate the unknown interferometric phase offsets without the use of ground control points or already calibrated data. Modifications in order to enhance the precision and robustness of the algorithm are presented and the new implementation is validated with X-band airborne SAR data. Furthermore, issues related with the use of the algorithm for P-band datasets are discussed and experimental results are shown for this kind of data. The stability of the algorithm according to the choice of the area of the image used for the estimation and to the choice of the coherence threshold is also verified for both X- and P-band data sets.