Remote Determination of Soil Moisture and Evapotranspiration from ThermalInfrared Measurements: A Continuation

摘要

This final report summarizes approximately 5 years of research work pertaining tothe remote estimation and monitoring of soil water content using thermal infrared measurements. The project began with the premise that soil water deficits and plant water stress are detectable with the aid of remote measurements of thermal infrared temperature, as obtained from aircraft or satellite. A formidable problem encountered during this project, however, was the effect of variable surface vegetation cover. The latter was found to exert a considerable scatter in the measurements of surface radiant temperature. Accordingly, we set ourselves the task to develop a method for determining soil water content in the presence of vegetation, such that the effects of the latter can be assessed separately from that of the surrounding bare soil surface. Because of its relatively high surface resolution and optimum time of overpass, the NOAA satellite, specifically its Advanced Very High Resolution Radiometer (AVHRR), is considered the best available vehicle available for making routine measurements of T(sub 0). Accordingly, most of our work involves AVHRR data.