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Remotely sensed data can potentially be used to develop crop coefficients over large areas and make irrigation scheduling more practical, convenient, and accurate. A demonstration system is being developed under NASA's Terrestrial Observation and Prediction System (TOPS) to automatically retrieve and pre-process appropriate satellite imagery, calculate vegetation index values, convert to estimates of fractional cover and crop coefficients, and deliver or archive the output maps. A user interface will allow convenient retrieval of spatially explicit crop coefficient estimates (e.g., individual fields, irrigation district) for combination with reference evapotranspiration (ETo) and other supporting datasets for derivation of crop ET. The system is intended to eventually support practical irrigation scheduling based on climatic information (as from the California Irrigation Management Information System) for more accurate irrigation water applications that meet crop water requirements