Quantifying shallow and deep permafrost changes using radar remote sensing. Soil moisture estimation using Sentinel -1 data.

Soil moisture is a major factor in permafrost aggradation and degradation. Active microwave sensors such as Synthetic Aperture Radar (SAR) have been used for detecting surface soil moisture. The measurements using SAR polarization data is most accurate and sensitive measurements, because the backscattering properties of soils and vegetation are strongly altered when transitioning between frozen and thawed states. The backscattering strengths of soils and vegetation components increase with water content in thawed state and measured by the active sensors. While in frozen form soils and vegetation have very low backscattering strengths.
We analysed available Sentinel-1 SAR data between 2015-2017. The Sentinel-1 data is C-band SAR sensor. The available data is dual polarization data with repeat pass time of 11 days that indicate seasonal changes in freeze/thaw processes. Using time-series analysis of Sentinel-1 data it is possible to identify spatial distribution and estimation of surface soil moisture.