Extraction and Geometrical Accuracy of Double-bounce Lines in High Resolution SAR Images

Abstract

In TerraSAR-X spotlight data features of man-made objects in urban areas become visible. In a case study, this paper presents results of a precision and geometrical accuracy investigation of extracted double-bounce lines in SAR images. Two TerraSAR-X (TSX) acquisitions of a complex urban scene are compared to simulated SAR images. Using a new line detection method, double-bounce lines are extracted from simulated and real imagery with sub-pixel accuracy. The deviation of an extracted double-bounce line polygon with regard to both an interpolated line and ground truth is analyzed and discussed. First, it is shown that Gaussian functions model the deviation of the interpolated line from the polygon sufficiently well. Second, the absolute geometrical accuracy of the extracted double-bounce lines is evaluated with respect to ground truth. Results of the case study confirm that double-bounce lines provide reliable geometrical information, for instance, for building extraction and SAR image classification.