Radarsat and Surface Character at Greenland Summit
Manninen, Terhikki; Lahtinen, Panu; Anttila, Kati; Riihelä, Aku
Finnish Meteorological Institute, FINLAND

The RASCALS campaign was carried out at the Greenland Summit camp research station during June - July 2010. The collection of surface roughness, dielectric constant and density profiles of snow were carried out concurrently with snow albedo and bidirectional reflectance distribution function (BRDF) measurements. Radarsat data were provided for a period from May to August, 2010 by ESA via the EU SOAR project, ID 6759 (ARCS). A few of them were taken during the measurement campaign. Favorable weather conditions during the campaign enabled the collection of a large dataset on Arctic snow albedo and associated quantities for use in developing and validating remote sensing algorithms for snow albedo using satellites. The surface roughness data contains about 500 individual 1 m long profiles taken in 16 days. The rms height, correlation length and autocorrelation function are determined. The dielectric constant and density of snow were obtained in 9 days for profiles of about 1 m deep with an interval of about 5 cm. Polarimetric interferometry of the Radarsat-2 quad pol fine beam images is used to study the snow surface anisotropy at Summit, Greenland. Various methods of determining the polarimetric coherence are carried out and the results are compared with the surface roughness results, which show a clear anisotropy varying with time. In addition, surface backscattering modeling is used to check the fraction of the surface backscattering.