POLARIMETRIC STATIONARITY CRITERIA APPLIED TO THE SELECTION OF PIXEL SCATTERERS CANDIDATES

摘要

In this paper we present a method to refine the selection ofrnpersistent scatterer candidates by means of a polarimetricrnstationarity test. In a previous work we achieved an increasernin the number of candidates selected by exploringrnthe available polarimetric space in order to optimize thernparameter used as selection criterion. The approach wasrnapplied to the most commonly used criteria of selection,rnnamely the amplitude dispersion index and the averagerninterferometric coherence. These criteria, however, makerna limited use of polarimetric information, since they werernoriginally conceived for single-pol data. The test proposedrnin this paper is aimed to check also the polarimetricrnstability of the points selected as candidates by traditionalrncriteria, thus making a more complete use of the polarimetricrninformation available. The method has been formulatedrnfor both multi-look (spatial averaged) and singlelookrndata and tested using dual-pol TerraSAR-X images.rnPreliminary results of the new selection of pixel candidatesrnare shown and discussed. They confirm the potentialrnof the polarimetric stationarity test for detecting andrndiscarding pixels that exhibit an unstable polarimetric responsernbut still they are selected by classic amplitude dispersionrnor coherence criteria.