Technical Abstract: Estimation and monitoring the spatial distribution of evapotranspiration (ET) over irrigated crops is becoming increasingly important for managing crop water requirements under water scarce conditions. The usual approaches for estimating ET, however, do not provide plot-specific data but instead produce spatially-averaged ET estimates. The only practical way to provide spatially-specific ET estimates is through remote sensing, which can observe ET-related surface properties such as vegetation density and surface temperature. A remote sensing approach that models ET including both of these observations involves using the surface energy balance, with water vapor transport as a key component. Using a two source energy balance model, ground control data, and sub-meter, airborne observations over a wheat irrigation experiment in Maricopa, Arizona in 2005 we showed that daily ET values could be accurately estimated over a wheat crop. Agreement with ET estimates based on soil moisture depletion observations was within 0.4 mm/d for most of the growing season, with exceptions for late-season senescent stages. These results suggest that spatially-distributed energy balance modeling can provide accurate daily ET estimates that are potentially useful to irrigation scheduling routines. They also indicate that optimal benefits from remote sensing will be achieved only when the estimates are integrated with nearly continuous observations from ground-based stations.