Multiple Incidence Angle SIR-B Experiment over Argentina: Stereo-Radargrammetric Analysis

Four overlapping SIR-B radar images were obtained across southern Argentina; these form a total of six stereo models with intersection angles ranging from 5° to 23°. This data set is uniquely suited for experimental evaluation of some basic assumptions on stereo -radargrammetry. Each stereo model was measured on a specially programmed photogrammetric analytical plotter; the resulting coordinates of ground points were compared with those from maps. It is concluded that accuracies are lower than expected at the larger stereointersection angles, amounting to about ±60 m in each coordinate direction. This might be explained by limitations of the quality of stereofusion caused by look angle differences and specular point migration, backscatter differences due to different incidence angles, differences in azimuth directions, and image noise and speckle.