INTEGRATION OF RADARSAT SAR AND AIRBORNE HYPERSPECTRAL IMAGERY: SODA BUTTE CREEK AND LAMAR RIVER VALLEYS, YELLOWSTONE NATIONAL PARK

摘要

Vegetation biomass in the Soda Butte Creek and Lamar River floodplains inrnnortheastern Yellowstone National Park was evaluated using Radarsat fine beam modernSAR imagery, integrated with land cover information derived from the airborne ESSIrnProbe-1 hyperspectral instrument. The SAR biomass algorithm is improved byrnincorporating the contribution to the backscatter of each vegetation class in the studyrnarea, based on the percent cover of each in 250 m square grid areas. The percent cover ofrnwoody vegetation (e.g. sagebrush, willow) and low backscatter vegetation types (e.g.rngrasses, lupine), along with bare soil areas are derived from classifications and thernapplication of vegetation indices to the high spatial (5 m) and spectral (128 bands, 0.4 torn2.5 ~m) resolution Probe-1 imagery. The 250 m square grids allow for Radarsat pixelrnaveraging, to reduce the effects of speckle and minor topographic undulations on thernbackscatter. In addition, two SAR images were acquired (17 August and 10 September,rn1999) with identical image pararneters to allow for further pixel averaging and to monitorrnsoil moisture effects. A field campaign during image acquisition was performed forrnground truth of the remotely sensed biomass and vegetation cover measurements. Thernmaps and processed imagery generated by this study are being incorporated into a GIS tornserve as a baseline for river and vegetation change studies, and to evaluate the effects ofrnfuture floods, vegetation disease, or fires on the riparian system.