The actual evapotranspiration from one test site in the northern part of Senegal was calculated using a combination of NOAA-AVHRR data and meteorological data. AVHRR data were calibrated and corrected for the influence of the atmosphere. The relationship ET - RN = ab(T(s) - T(a)) was established on the basis of in situ measurements of fluxes during a field campaign September-October 1988. The flux measurements are presented, and the influence of surface roughness on the relationship is analyzed. A simple method for time integration of actual evapotranspiration between days with satellite data is presented.