Amplitude time series analysis in detection of persistent and temporal coherent scatterers

Constraining the deformation analysis to scatterers with high phase coherence, known as persistent scatterers (PS), in the InSAR time series plays a major role in advanced coherent approaches such as Persistent Scatterer Interferometry (PSI). Although crucial in overcoming the shortcomings of conventional InSAR in retrieving the deformation signals, this constraint appears to be too strict and lead to information loss in cases where the scatterers are coherent in merely a short period of the time series. Exploiting such scatterers, referred to as temporal coherent scatterers (TCS), is a necessity in PSI analysis in order to enhance the density of the resulted point clouds and consequently the quality of PSI. In here, statistical properties of the SAR calibrated amplitude time series are exploited to propose a new method for detection of the TCSs and estimation of the coherent intervals. The proposed methodology also allows for estimation of signal to clutter ratio (SCR) as an indication of the phase coherence. The method is evaluated using the simulated SAR stack as well as TerraSAR-X high resolution complex images.