Identifying low reflection amplitude and low level phase noise points for permanent scatterer (PS) interferometry Conference Paper uri icon

abstract

  • The PSI (Persistent Scatterers Interferometry) method relies on identifying a small group of scatterers that maintain high phase reliability over a relatively long period of time. This study demonstrates a new algorithm to identify natural PSC (persistent scatterer candidates) targets in non-inhabited areas. The application of our PSC selection process is conducted for a natural arid scene as opposed to the more common use of the PS technique, which is done mostly for urban areas with structures exhibiting strong reflection (manmade objects). We present a novel robust method to identify PSC in open fields and in places of low backscattering (natural areas). Our method is based on the amplitude time history signature of each point. The main difference between urban areas and open field areas is the low reflectance and less deterministic behavior of the scatterer; hence it is a challenge to detect these low reflection and stable points. Conventional methods for PSC detection require a preprocessing with fine calibration and are mainly suitable to use in urban areas, but may fail when used in the open fields. One of the advantages of our method is the use of a simple process of calibration which is based only on the flight geometry and gain factors without any auxiliary data or assumptions. Consider a vector consisting of the measurement of a PS point as a function of time. We can express this signal as an amplitude times a phase. The amplitude differs between PS points; however potential PS points should correlate spatially and temporally in terms of the phase, independent of their amplitude. Our method improves locates several candidate points with a narrow phase distribution and thus, enables the location of PSCs in natural open areas.

publication date

  • November 1, 2011