基于TRMM卫星数据的降雨测量精度评价

Accuracy Assessment of Rainfall Measurement Based on TRMM Products

采用1999年1月至2007年12月TRMM3B43卫星降雨与中国718个地面雨量站实测月降雨量,通过对两套数据时空匹配,建立回归模型。结果表明,卫星数据与实测降雨量高度线性相关,其在中国东部和南部的拟合精度比西部和北部略高。由于TRMM卫星对强降雨、区域性降雨的遥测精度受限于雷达信号敏感度和分辨率,汛期TRMM测雨精度略低于非汛期,均在可接受范围内。TRMM卫星降雨资料覆盖全球中低纬度地区,对于无资料地区、大尺度范围,在中长期水资源规划、旱情分析等方面具有较强的实用性。

By contrasting the TRMM 3B43 dataset between January 1999 and December 2007 and the observations of 718 precipitation stations in China, a linear regression model is established to analyze the accuracy of TRMM rainfall measurement. There is a significant correlation between TRMM data and the observed ones, and the fitting accuracy of TRMM data performs better in eastern and southern China than in western and northern China. As limited by insensitive to high rainfall of radar signals and low resolution, the TRMM data have better results in dry season than in flood season, but all are in acceptable range. Because the TRMM data cover all middle and lower latitude area, it is useful for long-term water resources planning and drought analysis of ungauged basins.