Four-Images SAR Differential Interferometry

Abstract

First, interferograms combination is described. We show that the use of multiple interferometric pairs allows to increase or decrease artificially the ambiguity altitude and, thus, to decrease or increase the fringe rate in the resulting interferogram. In particular, this allows to generate DEM in regions having a highly energetic relief but at the cost of a lost of altimetric resolution.

Based on this technique of interferogram combination, Four-Images DInSAR is described and an exemple using two Tandem interferometric pairs covering the Jordan border of the Death Sea is presented. This exemple shows that even Tandem interferograms may contain fringes due to optical path variations. The correct interpretation of such fringes can only be performed with the help of ancillary data. This exemple shows that interferograms used as topographical reference must be chosen with care. A second exemple of "Four-Images DInSAR" is presented on the well-known Landers earthquake.

Keywords: SAR, Interferograms combination, Differential Interferometry, Atmospheric artifacts

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry