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PHOTOGRAMMETRY ROUND THE WORLD

Analysis and evaluation of the DEM derived from TOPSAR airborne interferometric SAR system. By L.-W. Wang and J. C. Trinder. The Australian Surveyor, 44(2): 174-182 (December 1999). An evaluation is made of the accuracy of the DEMs generated by the JPWNASA TOPSAR interferometric SAR system, by comparing them with an accurate reference DEM derived from the digital photogrammetric processing of 1 : 25 000 scale aerial stereopairs. The ground in the test site location was relatively flat, with a variation in elevation ranging from 29m to 115m. DEMs generated from the radar data were rotated and translated to overlay the reference DEM, allowing an analysis to be made of the height accuracy achieved. The r.m.s. errors, measured over an area of 4.5 x 2.5 km, were 3.9 m for the C-band interferometry DEM and 12,9111 for the L-band interferometry DEM. This paper gives background information concerning radar and SAR image formation, and describes the principles and applications of SAR interferometry. The key factors that currently limit the use of this technology are also discussed.