Discriminating forest cuts with ERS-1 radar imagery

Abstract
The capabilities of the ERS-1 SAR for discriminating clearcuts and partial cuts from open fields, wetland, and surrounding conifer, hardwood and mixedwood forest stands were tested. The test site contains both boreal and more temperate species. Two winter, one spring, four summer, and one fall image were registered to a UTM-corrected thematic mapper image. Separation of the backscatter signatures of different cut and forest conditions was analyzed visually and statistically. Discrimination and mapping capabilities varied with ground cover condition and, in some cases, environmental conditions. Overall separabilities were generally poor; consistent detection of the clearcut areas with the ERS-1 image dataset was not possible. Partial cuts were not detectable. The highest clearcut/forest and clearcut/wetland separabilities were observed in summer and winter imagery, although the results were not consistent. For example, two summer images acquired twelve hours apart provided quite different results. Some clearcuts were detectable on an image acquired at 2300 h, nine hours after a heavy rainfall. A second image acquired earlier that day at 1100 h during a light rainfall did not show the clearcuts. Clearcuts with bare sand or sparsely vegetated surfaces were the most likely to be detected. As ground vegetation density increased, discrimination generally became poorer. Clearcuts with rugged topography and rocky soils were not clearly separable from surrounding forests on any of the images.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.