Coupling Soil/Snow Energy Transfer Model and Active Microwave Radiative Transfer Model to Simulate C and X-Band SAR Data
Caron, Francis; Magagi, Ramata
Sherbrooke's University, CANADA
In Quebec, winter conditions often cause damages and productivity lost of perennial crops. Plants mortality during winter may be caused by several factors such as intensity and duration of low temperatures, roots encasement by ice and anoxia due to the presence of an ice layer on the fields. However, Quebec’s climate is known for its high amount of solid precipitation during winter so that the resulting snow depths help to attenuate the negative impacts of these factors on crops. Therefore, crops survival is closely related to the amount of snow during the winter. Understanding the interactions between soil, snow and atmosphere are thus of great importance in agriculture. Due to their penetration depths, microwave signals can offer an interesting potential in studying these interactions which are complex and require a detailed knowledge of the characteristics of the media. In Quebec, snow depth and soil temperature are often monitored using measurements collected at only few meteorological stations. In order to overcome this problem, the objective of our study is to investigate the possibility of using outputs of a snow/soil model which considers energy transfer and mass balance to simulate the C and X-bands radar backscattering coefficients. The approach consists of using meteorological data to generate soil and snow characteristics from the Simultaneous Heat and Water (SHAW) model. The results will be validated with field measurements of snow (stratigraphy, density, temperature and grain size) and soil (temperature and humidity) characteristics. Then, using a radar radiative transfer model together with Radarsat-2 and TerraSAR-X acquisitions, a comparison will be made between the performance of in-situ measurements of soil and snow and SHAW outputs for the modelling of C and X-bands radar backscattering coefficients.