Snow Depth Changes Over the Alps Using Polarimetric Synthetic Aperture Radar Data

In this work, RADARSAT-2 Polarimetric Synthetic Aperture Radar (PolSAR) data are used to investigate the snow depth changes over the Alps. Multi-temporal RADARSAT-2 data (5 scenes) were acquired in the same orbit with same incidence angle during Dec 2017 - Mar 2018. The Automatic Weather Station (AWS) data from IDAWEB along with the manual snow depth measurements are used for the analyses. Polarimetric coherency matrix elements and various PolSAR decomposition parameters are derived from the RADARSAT-2 data. These parameters are regressively investigated with the AWS and In-situ snow depth measurements along with the temperature and precipitation measurements. The PolSAR parameters also investigated with different snow conditions.

It is found that dominant scattering type phase (Φs1) and helicity (Τ1) from Touzi incoherent polarimetric decomposition method [1] and T₁₂ Phase from coherency matrix is providing useful information about the snow depth. The promising results achieved from this investigations lead to the development of new snow depth estimation algorithm with high spatial resolution using the full utilization of PolSAR data.

[1]. R. Touzi, "Target Scattering Decomposition in Terms of Roll-Invariant Target Parameters," in IEEE Transactions on Geoscience and Remote Sensing, vol. 45, no. 1, pp. 73-84, Jan. 2007