Topographic Mapping From ERS-1 And Seasat Radar Interferometry

A radar interferometric technique for topographic mapping of sur- faces promises a high resolution, globally consistent approach to gen- eration of digital elevation models. Utilizing a single synthetic aper- ture radar satellite in a nearly repeating orbit is attractive for cost and spaceborne hardware complexity reasons; also it permits infer- ence of changes in the surface from the correlation properties of the radar echoes. We illustrate the technique with maps generated from SEASAT and ERS-1 data. We have analyzed a SEASAT interferomet- ric image of a forested area in Oregon which includes some unvegetated lava flows. We also present an analysis of errors expected from appli- cation of the technique to maps generated from ERS-1 data collected over Alaska; as of the time of this writing we have not yet generated the maps themselves. Finally we outline an orbital scenario for a global mapping mission.