Point target interferometry for natural and artificial scatterers

The Coherent Targets Monitoring technique is providing superior ground deformation mapping compared with standard interferometry based on one pair of Master/Slave scenes. This is because using a larger data set it is possible to estimate and correct for additional phase error sources. Also the point targets detected as coherent targets are generally characterized by stronger signal that provides more accurate phase information than the clutter present in the rest of the scene. This paper reviews previous work in SAR noise estimation and shows the advantages of point targets versus distributed targets. Results from the Turtle Mountain/Frank Slide site show that the measured phase/deformation errors at the point target positions are within the estimated range. Corner reflectors with a high SNR are expected to improve the accuracy of the method.