Validation of the NEXRAD DSP Product with a Dense Rain Gauge Network

AbstractThe Next-Generation Weather Radar (NEXRAD) system digital storm-total precipitation product (DSP; 2  km×1° at 4–7-min intervals) is examined for its quality in terms of precipitation quantity and spatial rainfall distribution. Observations from a network of 50 rain gauges in the Upper Guadalupe River Basin are compared to the DSP rainfall estimates from two radars: KEWX at New Braunfels, Texas, and KDFX (14 km east of Brackettville, Texas), for the period of September 2006 to June 2008. The rainfall data comparisons are conducted at three temporal scales: 6 min, 1 h, and storm-total accumulations, and at different distances from the radars, from near ( 160  km). A strong range dependence is found from radar estimates, i.e., radar underestimates at near and very far ranges ( 160  km), matches well or slightly overestimates at middle ranges (50–100 km), and overestimates at far ranges (100–160 km). The correlation coeffic...