Accuracy assessment and error cause analysis of GPM (V06) in Xiangjiang river catchment

Abstract

Application potential and development prospect of satellite precipitation products such as Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Mission (GPM) have promising implications. This study discusses causes of spatiotemporal differences on GPM data through the following steps: Initially, calculate bias between satellite-based data and rain gauge data of Xiangjiang river catchment to assess the accuracy of GPM (06E, 06 L, and 06F) products. Second, total errors of satellite precipitation data are divided into hit bias (HBIAS: precipitation detected by both GPM and rain gauge station), missed precipitation (MBIAS: precipitation detected only by rain gauge station), and false precipitation (FBIAS: precipitation detected only by GPM). Third, evaluate the impact of precipitation intensity and total precipitation on accuracy of GPM data and their influence on three error components. Several conclusions are drawn from the results above. (1) Satellite-based precipitation measurements perform better on a larger temporal-spatial scale. (2) The accuracy of TRMM and GPM data displays significant variances on space and time. Season, precipitation intensity, and total precipitation are main factors influencing the accuracy of TRMM and GPM data. (3) The detection capability of satellite products change with seasonal variation and different precipitation intensity level. HIGHLIGHTS GPM products have wider spatial coverage, higher temporal and spatial resolution than TRMM products.; GPM products are more in line with the data requirements of hydrological simulation and forecast.; Evaluate accuracy of different GPM products in precipitation measuring, including early, late and final products.; Assess the improvement of GPM products comparing with its predecessor, TRMM.;

Keywords

• accuracy assessment
• error components
• extreme events
• precipitation intensity
• satellite measurements