Performance of the first European 482 MHz Wind Profiler Radar with RASS under operational conditions

Abstract

The first 482 MHz Wind Profiler Radar (WPR) in Europe completed with a Radio-Acoustic Sounding System (RASS) has been operated at the Meteorological Observatory Lindenberg since July 3rd, 1996 after a comprehensive study regarding the investigation of frequency compatibility between the WPR and the television channel 22 (478-486 MHz). The WPR can operate with different height and time resolutions (e. g. 250 m in the so-called Low Mode or 500 m in the High Mode). A height range of up to approximately 16 km can be realized in the High Mode. The installed WPR/RASS combination allows also the measurement of profiles of the virtual temperature with the Low Mode resolution in the height range from 500 m up to approximately 4000 m. The main objective of this contribution is the investigation of the accuracy and the availability of this new remote sensing system. First results of the accuracy can be given on the base of about 1000 intercomparisons between WPR/RASS and Rawinsonde data. The bias of the horizontal wind velocities is less than 0.4 m/s in the Low Mode and 0.7 m/s in the High Mode (from 3 to 10 km) and therefore smaller than the average accuracy of both systems. The bias of the temperature measurements is less than 1 K and can be improved by some corrections in future. A first statistics of the data availability can be shown based on nearly 6000 profiles of wind and temperature. The 80 % availability of the WPR/RASS was determined with 12.8 km for wind and 2.3 km for temperature measurements. The new possibilities of investigating the troposphere as well as the lowest part of the stratosphere are presented by measurement examples from February and March 1997.

Keywords

• radio-acoustic sounding system