Research Projects

Traditional GNSS signals are utilized for positional and navigational applications, however, GNSS has also been regarded as a powerful emerging space-borne technology for non-positioning applications. Since last two decades attempts have been made to utilize GNSS signals (direct or reflected) for retrieval of various geophysical parameters viz. soil moisture, water level, snow depth, crop height, Percipitable Water Vapour, etc. The ground-based GNSS-MET is proved to be complementary to the conventional sounding means of PWV due to its real-time, allday and all-weather capabilities and high temporal resolutions. In the past few years new GNSS space constellations other than GPS and GLONASS have emerged. Along with GPS, GLONASS, BeiDou Navigation Satellite System (BDS), Galileo, QZSS, India has it’s own regional navigation system; IRNSS. In this study, the change in the reflected signals of IRNSS (NavIC) constellation with change in nature/state of the reflecting surface will be analysed to develop models for retrieval of these surface parameter i.e. change in soil moisture, snow depth and water level. Also the direct signals from IRNSS and other GNSS satellites will be utilized for retrieval PWV. The derived products from these projects can be utilized for validation of other remote sensing based products and calibration/validation of modeling based products.