A mode based auto-adaptive median filtering method for interferometric phase

In order to improve the phase noise reduction effect and to avoid filtering useful phase jumps, this paper first investigates mode filtering algorithm and proposes a modified mode estimator based on shortest sub-interval seeking for interferometric phase. By further analysis of relationship between mode estimating parameter and phase resolution, an auto adaptive local phase center with variation of interferometric phase quality is constructed, based on which an adaptive median filtering method is presented. This method could overcome the edge blur problem caused by mode filter, and is also effective to avoid over filtering or under filtering caused by conventional spatial filter with uniform parameter. Meanwhile, it achieves better computation efficiency. Finally, experiments with simulated and real TerraSAR-X data are performed to testify the effectiveness of this method.