Study of GPS C/No ratio for retrieval of Surface Soil Moisture

In this paper, soil moisture retrieval algorithm has been developed utilizing Global Positioning System (GPS) C/No data for bare soil surfaces. The developed algorithm relies on the multipath carrier to noise ratio (C/No) recorded by the receiver. Indian Regional Navigational Satellite System (IRNSS) receiver was used to collect the multipath GPS data from bare soil. Change in C/No was analyzed with elevation angle and it was observed that low elevation angles are suitable for estimation of soil moisture. An empirical relationship was developed between soil moisture and amplitude of fitted C/No data. This developed relationship can be utilized to retrieved soil moisture with GPS C/No data. Obtained results were compared with the soil moisture retrieved with Gravimetric method. Good agreement was observed between the soil moisture retrieved through Gravimetric method and soil moisture retrieved through developed relationship with GPS C/No data.