The PS-InSAR method results are highly depending on the Persistent Scatters Candidate (PSC) selection process. This study implements a new algorithm for detection of PSC in open fields and natural areas based on high resolution TerraSAR-X images. The main challenge in PSC detection in natural areas is the lack of strong reflected targets in these areas. This cause high number of diverted targets, or low number of true PS targets (depend on the thresholds). Conventional methods for PS detection are highly depending on the fine calibration, and on the scaling of the target within the resolution cell. Our method is more robust since it less depends on fine calibration, and not depends on the target gain. The method consists of two main steps. The first step is definition of a PSC target character i.e. its amplitude time signature (ATS). The second step is detection of pixels with the same (close enough) temporal signature cone, this way strong and weak reflectors get the same chance to be a mark as a target.