A Radar Image Time Series

A set of side-looking radar images has been collected over an area in the Sierrita Pediment, Arizona, U.S.A. The dates of image acquisition vary from 1965- 1979 and the images are taken at various look angles, frequencies, flight directions and polarizations. The objective of the study is to demonstrate the photogrammetric orthophoto technique applied to radar images and at the same time to study the characteristics of this unique set of radar images taken over the same area by many different sensors. Ten images are presented here, of which five have been rectified using ground control points and a digital height model taken from a map. Errors prior to rectification are shown to amount to several hundred metres on the ground in all cases; after rectification, residual coordinate errors in ground control range from ± 19 m to ±70 m. The contents of the radar images, including one pass from Seasat, were compared with a Landsat image and aerial photography. Observations made confirm a range of conclusions on the effect of system parameters on the radar image. The data set also permitted a unique review of changes that occurred in the area over time, and of variations in radar performance as a function of some system parameters.