Identification of Coherent Scatterers: Spectral Correlation vs. Multi-Chromatic Phase Analysis

In recent years, attention has been devoted to the possibility of retrieving accurate phase information from stable targets in long SAR data series through Permanent Scatterers Interferometry (PSI), SBAS approach or equivalent methods. Recently, alternative methods for detecting stable targets on single images have been investigated. In particular, the availability of new SAR sensors provided with innovative features, including a wider transmitted bandwidth, allows to explore backscatter stability in the new dimension given by spectral diversity. The Multi-Chromatic Phase (MCP) approach, introduced in [2], uses images processed at range sub-bands and explores the phase trend of each pixel as a function of the different central carrier frequencies. In this paper we present the results of the application of this technique to point target detection. We compare the results with an alternative method proposed in [5] which identifies scatterers with stable spectral behavior.