INFERENCES ON SPATIAL AND TEMPORAL VARIABILITY OF THE BACKSCATTER FROM GROWING CROPS USING AGRISAR DATA

AgriSAR 86 data from the Feltwell Site, U.K., was affected by a variety of radiometric distortions. These distortions prevent accurate calibration of the images, but analysis of the image statistics, after some radiometric corrections have been performed, permits a number of qualitative inferences about variations in crop backscatter in time and space. Cereals and sugar beet appear to exhibit different incidence angle responses. The separability of wheat and sugar beet varies with time and incidence angle. The separation of spring barley and wheat varies with time. Cereals show greater spatial variability than sugar beet. Individual fields exhibit great apparent variability in their temporal responses; for sugar beet this can in the main be explained by the effects of speckle, but there is some evidence of real variation for winter wheat.