Potential of IRS-P4 microwave radiometer data for soil moisture estimation over India

Soil moisture at different temporal and spatial scales is very important for various applications. At smaller spatial scales it has importance for the agro-meteorological applications, whereas at large spatial scales it is an important boundary parameter in the numerical prediction models of atmosphere for monthly to seasonal time-scale integrations. Frequent in situ global measurements of soil moisture at these spatial scales are virtually impossible because large heterogeneity of soil types makes these observations highly expensive and time consuming. Satellite based microwave radiometers can provide indirect estimates of soil moisture at resolutions compatible to that of climate models (50-100 km). In this paper the potential of Multi-frequency Scanning Microwave Radiometer (MSMR) onboard Indian satellite IRS-P4 is assessed for large area averaged soil moisture estimation. These are compared with the weekly-observed in situ soil moisture data over a few observatories of India Meteorological Department (IMD).