Comparison of vegetation water content estimates from WindSAT AND MODIS

Retrieval of soil moisture content from microwave sensors also returns an estimate of vegetation water content. Remotely sensed indices from optical sensors can be used to estimate canopy water content. For corn and soybean in central Iowa, there are allometric relationships between canopy water content and vegetation water content. The Normalized Difference Infrared Index from MODIS was used to estimate vegetation water content. We compared independent estimates of vegetation water content from WindSat and MODIS over central Iowa from 2003 to 2005. There was a strong linear relationship between the MODIS and WindSat estimates, but the WindSat estimates were about two times higher. These results suggest that soil moisture retrievals from microwave sensors may be more accurate with estimates of vegetation water content from optical sensors.