Mapping field crop evapotranspiration using airborne multispectral imagery

Multispectral video images were collected over a wheat field in Smithfield, Utah. The data included digital images in the green, red, near-infrared and thermal-infrared portion of the spectrum. The images were registered to each other. Three layers of reflectance and a surface temperature layer were computed from the images. Spatially distributed net radiation, soil heat flux and sensible heat were estimated using the layers along with meteorological data from the USU drainage farm weather station. The estimated fluxes were compared to independent measurement from a Bowen ratio energy balance system setup in the field