Network Architecture for Small X-band Weather Radars – Test Bed for Automatic Inter-calibration and Nowcasting

In recent years the use of small inexpensive Xband radars for meteorological and hydrological purposes has increased significantly. Compared to the traditional C-band and S-band radars the X-band weather radar has the advantage of high temporal and spatial resolution and low financial cost; however, the trade off is attenuation due to X-band technology and short range due to the higher spatial resolution. In relation to quantitative precipitation estimation (QPE) and forecasting (QPF) it is necessary to address the attenuation issue. Over the next two years a test bed with five X-band radars of the type Local Area Weather Radar (LAWR) will be set up south of Aarhus in Denmark. The three radars will be placed so that they overlook the same area and thereby are capable of intercepting a precipitation event from different angles, altitudes and ranges. The overall aim is to construct a network of small X-band radars which are capable of automatic inter-calibrating and inter-correcting for attenuation on the fly by online communication. From the beginning the LAWR has been equipped with a set of attenuation corrections algorithms. However, verification of these algorithms has not been possible so far, due to lack of multi radar measurements of rainfall events. The prospects of verifying and possibly improving the method used for correction of attenuation using radar networks are promising. The results from the test bed are expected to optimize attenuation handling and improve nowcasting capabilities.