Radar precipitation measurement in a mountainous region

Real-time precipitation measurement by radar in a mountainous region requires appropriate system design and innovative solutions. Of particular difficulty are the elimination of ground echoes and the correction of errors caused by shielding of the radar beam by mountain ranges. This paper presents the Swiss solution with a focus on recent modifications. A large-sample comparison between radar precipitation estimates and ground observations from a high-resolution gauge network reveals distinct improvements achieved by the modifications of the past 8 years. The verification takes into account all days of the period 1997-2004 and gauge locations spread over all of Switzerland. Particular attention was paid to the definition of a set of meaningful and robust quality parameters. This rigorous and systematic verification approach may become a standard for objective judgement of radar performance.