Comprehensive QPE Demonstration in the IP1 Test bed

Quantitative precipitation estimation (QPE) is an important application of weather radar systems and a means to monitor rainfall intensity and forecast flooding risk. It is well known that rainfall estimation is a very challenging process. Under the DCAS paradigm, the radar observations at high spatiotemporal resolutions will improve the accuracy of rainfall estimation and eventually flood warnings. In the IP1 network, multiyear rainfall events since 2007 were analyzed to investigate QPE performance. IP1 rainfall estimates for 29 storm events from 3 years were compared to the ground in-situ measurements from ARS's Little Washita gauge network.  The cross-comparison was performed over each rain gauge station for each storm event. This multiyear study reveals almost negligible estimation bias and small standard errors. The NSE (normalized standard error) for instantaneous rainfall rate is 42.41% and the corresponding error for hourly rainfall is 15.78%. The excellent performance of the IP1 QPE demonstrates the benefits from measurements close to the ground and the networked sensing operation. The study also proves the reliability of X-band weather radar system achieved through a dense network deployment for QPE.  These results are more than a factor of two improvement compared to the same set of studies conducted over the same basin by KOUN radar for hourly rainfall accumulations.

 The distribution of ARS Micronet gauge network within the IP1 network coverage. The current operational gauge stations are marked in ‘x' on the left side. The zoom-in view of the Little Washita watershed is shown on the right side labeled with station IDs.