The thesis deals with snow water equivalent (SWE) estimation using Polarimetric SAR (PolSAR) data at C- and X-band. SWE retrieval methodologies are developed using PolSAR, targeting mono-, dual-, and full-polarization SAR data. Field-based measurements have helped in the development and validation of the proposed algorithm. Four algorithms of SWE retrieval using PolSAR data are presented, and outcomes are validated using near-real-time in-situ measurements collected during field campaigns (in 2016 and 2018) at Dhundi Observatory, Manali, Himachal Pradesh, India (study area). These algorithms are compared for spatial resolution, inversion accuracy, and polarization requirement.