Crop surface temperature estimation in irrigated command areas using MODIS satellite data

Crop surface temperature (CST) is an important parameter to monitor crop status. Satellite data in thermal region provide an opportunity to estimate CST over large regions at frequent intervals. In the present study, various split-window algorithms are employed to estimate CST over rice areas in irrigation projects of Krishna basin, South India using multi-resolution MODIS satellite data. NDVI is used to approximate the mean pixel emissivity, by taking known values for emissivity and NDVI for pure vegetation and bare soil pixels. Diurnal ground measurements are made to evaluate satellite-derived CST. CST values obtained using the Sobrino method have been found to be closer to the ground-measured values compared with other algorithms, as it takes into account view angle, atmospheric transmittance, and water vapour corrections. It has been observed that the error in estimating CST is comparatively lower for well-grown crops.