Analysis and evaluation of the NASA/JPL TOPSAR across-track interferometric SAR system

We have evaluated the accuracy of digital elevation models (DEMs) generated by the JPL/NASA TOPSAR synthetic aperture radar interferometer instrument by acquiring topographic data in the summer of 1992 over the National Training Center, Ft. Irwin, California, a desert area with significant relief and varied terrain, and comparing the measurements to a very accurate digital elevation model derived for this area by the U.S. Army Topographic Engineering Center (TEC). Fiducial comer reflectors were deployed in the area, and their locations were determined to cm accuracy by the Defense Mapping Agency (DMA) using differential GPS techniques. DEMs generated from the acquired radar data were rotated and translated to precisely overlay the reference DEM, allowing an in-depth analysis of the achieved height accuracy. We present here a detailed description of horizontal and vertical errors and their characteristics. The standard deviation measured over a 5.6 by 7 km area was approximately 2 m, the corresponding figures for relatively flat areas were in the 1 to 2 meter range and for mountainous areas in the 2 to 3 meter range, which are consistent with theoretical expectations. We also discuss key factors that presently limit the system performance. Keyword.r: SAR interferomctry, topogmphic mapping, 3-D imaging radar Version 1.2, October 14, 1993,9:55 Submitted to the IEEE transactions for Gcoscicncc and Remote Sensing on 93/09/DD Please addn.xs any communication to: S@rcn N@vang Madsen, MS 300-235 Jet Propulsion Laboratory 4800 Oak Grove Dr. Pasadena, CA 91109 Phone: (818) 3548353 Fax: (818) 3935285 E-mail: sorcn@tivoli,jpl .nasa,gov , f Version 1.2, October 14, 1993,9:55 page 2