Use of polarimetric indices for estimating soil moisture

The application of Synthetic Aperture Radar (SAR) data for estimating soil moisture in the vegetated covered areas is still challenging task because variation of the vegetation over the soil surface is difficult to predict. Thus, there is a need to develop such an approach for soil moisture retrieval which can minimize the vegetation effects. Various models are available in the literature for soil moisture retrieval but either these models are very complex or they required more than one satellite data. Therefore, in this paper, an attempt has been made for minimizing the crop effect while retrieving the soil moisture by using same satellite data (i.e., PALSAR data) only. For this purpose, the application of polarimetric information may be useful because polarimetric indices give physical significance in discriminating the vegetated cover areas from other regions (water bodies, urban areas, bare soil) of the earth´s surface. So, these polarimetric indices have been critically analyzed for the minimization of crop effect and a model has been developed for soil moisture retrieval by using the polarimetric indices SPAN and RVI.