ESTIMATION OF LAND-SURFACE PARAMETERS USING SATELLITE DATA

Surface observations and NOAA advanced very high resolution radiometer (AVHRR) satellite data are combined to provide area-averaged values of albedo, canopy resistance, leaf area index and fractional vegetation cover. Albedo, fractional vegetation cover and leaf area index are derived from the reflectance of the visible and infra-red NOAA AVHRR channels. Canopy resistance is estimated by closing the surface energy balance equation using the surface infra-red temperature and the normalized difference vegetation index. These land surface parameters are evaluated against independent measurements and used as input into a numerical model to simulate the energy exchange between the surface and the overlying atmosphere. Simulation results are validated against detailed aircraft observations undertaken in south-western Australia over both natural and agricultural vegetation.