Mentor: M. Toporov
SNOHAT – Snow Humidity and Temperature Profiler (snow refers to its snowy environment, not to a device feature) is a HATPRO radiometer that is installed permanently at the Umweltforschungsstation Schneefernerhaus (UFS). Its purpose is to continuously monitor cloud liquid water path (LWP) and integrated water vapour (IWV) in a high alpine environment using 7 brightness temperature measurements between 22.235 and 31.400 GHz. The combination of these frequencies with the 90 and 150 GHz channels of the Dual Polarization Radiometer (DPR, also located at UFS) are specifically valuable for inferring super-cooled low LWPs. Methods for combining both instruments are currently under development. Additionally 7 SNOHAT measurements between 51.26 and 58.00 GHz, along with an elevation scanning procedure (every 15 minutes), allow the retrieval of high-quality temperature profiles. For more information on the applied statistical retrievals see Crewell and Löhnert (2007).
SNOHAT (RPG HATPRO) at UFS, Zugspitze, Germany.
The figure shows the relative humidity (RH, top row) and temperature (second row) of the environment as well as the Integrated Water Vapor (IWV, third row) and Liquid Water Path (LWP, last row) derived from SNOHAT.
|Receiver 1||water vapor and liquid water absorption|
|Frequencies [GHz]||22.24, 23.04, 23.84, 25.44, 26.24, 27.84, 31.40|
|Channel band-widths [MHz]||230, 230, 230, 230, 230, 230, 230|
|Optical Resolution (HPBW)||3.3°-3.7°|
|Receiver 2||oxygen absorption|
|Frequencies [GHz]||51.26, 52.28, 53.86, 54.94, 56.66, 57.30, 58.00|
|Channel band-widths [MHz]||230, 230, 230, 230, 600, 1000, 2000|
|Optical Resolution (HPBW)||2.2°- 2.5°|
|Side-lobe level||< -30 dBc|
|Size||630 mm x 360 mm x 900 mm|
|Power Consumption||<150 W (350 W peak) + dew blower|
|Temporal Resolution||1-2 sec|