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The directional emissivity of snow and ice surfaces in the 8 – 14 Am thermal infrared (TIR) atmospheric window was determined from spectral radiances obtained by field measurements using a portable Fourier transform infrared spectrometer in conjunction with snow pit work. The dependence of the directional emissivity on the surface snow type (grain size and(More)
—We present a comparison between data acquired with frequency-modulated ground-penetrating radar (GPR) and satellite synthetic aperture radar (SAR). Both radars are polarimetric and operate at a center frequency of 5.3 GHz. The field site is the polythermal glacier Kongsvegen, Svalbard. Along glacier GPR profiles cover the ablation area and the accumulation(More)
—The question of penetration of synthetic aperture radar (SAR) signals at C-band frequency into polar glaciers is addressed by comparing ground penetrating radar (GPR) and SAR backscatter signatures. Profiles of the Kongsvegen glacier, Svalbard, were obtained with a C-band GPR. The received signal is converted to the equivalent radar cross section using the(More)
—Frequent mapping of snow parameters, like snow cover area (SCA) and snow surface wetness (SSW), is important for applications in hydrology, meteorology and climatology. In this study we have developed a few general multi-sensor/time-series approaches for such monitoring. The objective is to analyze, on a daily basis, a time series of optical and Synthetic(More)
—The paper presents results from a series of European and national projects on remote sensing of snow parameters. Currently, satellite borne syntethic aperture radar (SAR) data are only available at C-band frequencies. Other frequencies such as L-band or Ku-band may be favorable in several snow applications, but current C-band SAR may still be used and(More)
The ENVISAT satellite with its many sensors opens for new, interesting approaches of combined multi-sensor, multi-temporal monitoring. In this study, we have focused on monitoring of snow parameters in the snowmelt seasons of 2003 and 2004 (April-June) in South Norway. The sensors used in this study are ENVISAT MERIS and ASAR and Terra MODIS. The study is(More)
The overall idea behind the work presented is to combine the use of optical and SAR sensors and utilise the best features of each sensor when possible in order to map snow cover area (SCA) more frequently and with better spatial coverage than would otherwise be possible. Optical remote sensing sensors are able to map snow cover quite accurately, but are(More)
— It has previously been shown that wet snow can be detected using ERS SAR repeat pass imagery where a reference image is captured during cold dry snow conditions and subtracted from the image one want to classify. We have extended and validated this technique for retrieving snow covered area (SCA) using Envisat ASAR wide swath data (500 by 500 km swath(More)
Estimation of total snow mass by means of SAR interfer-ometry is problematic, due to high sensitivity of the in-terferometric phase to the snow water equivalent, leading to the phase unwrapping problem. In this paper, we pursue a recently proposed technique, delta-k interferometric phase estimation, that avoids phase wrapping by lowering the sensitivity of(More)