Aspect and incidence angle sensitivity in ERS-1 SAR data

Abstract

Large variations in backscattering coefficients were observed on ERS-1 SAR images acquired from ascending and descending orbits, within 36 hours, over an agricultural area and under stable winter conditions. Three possible causes were investigated: (1) environmental factors; (2) SAR processor instability; and (3) aspect and incidence angle sensitivity. The look direction (aspect angle) accounted for a 1.5dB difference in backscattering coefficients. The remaining variations were related to the incidence angle. A correction model is proposed.