3D SAR imaging of the snowpack in presence of propagation velocity changes: Results from the AlpSAR campaign
In this paper we present results relative to the 3D GBSAR surveys acquired in february 2013 on the Austrian Alps as a part of the ESA campaign AlpSAR. The GBSAR was operated at X- and Ku-Band with a bandwidth of 4 GHz and employing a 2D synthetic aperture, resulting in 3D resolution capabilities at a resolution of few centimeters. Images produced at two different sites reveal the presence of multiple layers within the snowpack. The strongest backscatter contributions have been observed to correspond to bottom layers, that dominate the ones from the snow/air interface and the near subsurface. GBSAR data are observed to provide sensitivity to the propagation velocity into the snowpack, as revealed by the apparent depth variation with respect to the incidence angle.
High resolution three-dimensional imaging of a snowpack from ground-based sar data acquired at X and Ku Band
In this paper we present experimental results relative to the vertical structure of a 60 cm snow-pack as sensed with X- and Ku-Band microwaves. The available data are from a Ground Based (GB) SAR campaign carried out by the University of Rennes I in December 2010 at Col de Porte, in the French Alps, in collaboration with Meteo-France. The data have been acquired by moving a VNA along two orthogonal directions, so as to obtain a two dimensional synthetic array. This allowed to focus the signal in the three dimensional space, thus providing a direct imaging of the vertical structure of the snow-pack at a resolution of few centimeters. Results revealed the presence of strong backscattering contributions from beneath the snow layer, that appear to be linked to the presence of an ice layer.
Determination of the Water Content of Snow from the Study of Electromagnetic Wave Propagation in the Snow Cover
Abstract We propose a method for measuring in situ and continuously, the water content of a sample of snow in the snow cover. This method is based on the measurement of the attenuation of an electromagnetic wave propagating in a sample of snow situated between two antennae, an emitter and a receiver. The working frequency is 9.4 GHz.