<title>Stereoscopic intersection of satellite SAR data by using equivalent scan-line projection geometry</title>

Abstract

Because of the ability to provide data of the earth's surface independent from sun illumination and cloud coverage, SAR has become a valuable complement to optical remote sensors, such as SPOT HRV, MOMS-2 etc. In this paper, the equivalent scan-line projection geometry is adopted to carry out the stereoscopic intersection of satellite SAR data. According to this geometry, the collinearity equations can be written to express relations between the image points and the corresponding ground points. Then the collinearity equations are used to compute the orbital parameters for each image of the stereopair, respectively, which is called the backward space intersection. By using the collinearity equations combined with the computer orbital parameters and the measured image coordinates, the forward space intersection is carried out, from which the slant distances R<SUB>1</SUB>, and R<SUB>2</SUB> from an unknown ground point to the left and right antennas are computed, followed by the computation of the range difference dR; and then the relevant relations between the unknown ground coordinates and the distance difference dR are used to compute the unknown ground coordinates.