Snow development characteristic and the liquid water content dynamic on glacier snow packs are very important parameters that may be monitored by radar. Accurate ground reference is required for the radar image calibration. The authors developed a new in-situ snow moisture and density measuring device. Measurements were made with this advanced device in the winter of 1995/96 in Germany and in the winter of 1996/97 on the glacier Plaine de la Morte, Switzerland. The authors report on the correlation between in-situ and remotely sensed data concerning liquid water content and density. Furthermore they compare the gravimetric measured snow densities with their method. This winter one device is installed in Germany and a second one is delivered to the Antarctic Peninsula, where the project crew of DYPAG will operate it. The device consists of a net of radio frequency transmission lines and of high and low frequency impedance analyzers. Preinstalled lines are enclosed by snow fall. The analyzers measure the dielectric coefficients a of the snow mixture along the transmission lines. One sensor line can have a length of approx. 100 m. In a cross laid pattern the covered area can be larger than the pixel size. In this manner a representative area can be measured non-destructive and long-term. Every in-situ snow measuring device has a disturbing air gap to snow. The authors' new device cancels out this basic drawback. The determination of liquid water content needs the knowledge of density, too. In this case, the same device, the net of lines, measures the density inherent. With reconstruction of transmission line parameters it is possible to localize ice lenses and percolation downflows along the line. The sensor is equipped with an hourly data logging.
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