Inversion study of rainfall intensity field at all time during Mei-Yu period by using MTSAT multi-spectral imagery
Inversion study of rainfall intensity field at all time during Mei-Yu period by using MTSAT multi-spectral imagery
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DOI：
10.1117/12.804842
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发表时间：
2008-12
期刊：
影响因子：
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通讯作者：
Chenxi Wang;F. Yu;Yongjing Zhao
中科院分区：
文献类型：
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作者：
Chenxi Wang;F. Yu;Yongjing Zhao
对MTSAT多光谱卫星图像降雨强度场的反演进行了研究，提出了“单元特征空间分类法”，为实现对地静止卫星实时降水的连续观测奠定了基础。该方法将MTSAT多光谱卫星实测值与2007年中国东部(江苏、浙江、安徽)梅雨季高密度地面站的实测值相结合进行协同分析，较好地建立了各降水概率水平和各降水强度在不同的二维和三维光谱特征空间上的分布特征。在此基础上，建立了不同光谱组合的降水概率和降水强度的判别矩阵。不同的频谱组合分别用于构造白天和夜间的鉴别矩阵。白天提供IR1(11微米)、IR3(6.7μm)、VIS(0.7m)、IR12(TIR2-IR1)和IR13(TIR3-IR1)，其中主要使用IR1、VIS和IR3(或IR13)；夜间主要使用IR1、IR3、IR4(3.7μm)、IR12、IR13、IR14(TIR4-IR1)和IR24(TIR4-IR2)，主要使用IR1、IR3和IR24(或IR14)。利用中国地区2007年基准站和基准站的降水资料与实测降水资料进行对比检验表明，30%的降水概率能较好地区分降水区和非降水区，降水强度类别分析与实际情况吻合较好。众所周知，卫星观测是每小时一次的瞬时观测，而雨量计观测是一个小时内的累积过程。误差研究进一步表明，两种观测方法之间的差异是造成相对误差的重要原因。
The retrieval of MTSAT multi-spectral satellite image rainfall intensity field was studied, with which the "Unit-Feature Spatial Classification (UFSC) method" was proposed to become the foremost basis of the possibility of continuous observation of real-time precipitation from geostationary satellite. In this method, MTSAT multi-spectral satellite measured value and measured precipitation rate from high density ground stations of plum rain season in east china (Jiangsu Province, Zhejiang Province and Anhui Province) in 2007 are combined to conduct the cooperative analysis, and therefore the distribution features of the level of each precipitation probability and each precipitation intensity are well established on different two-dimensional and three-dimensional spectral feature spaces. On the basis, the discrimination matrices, correspondingly, are established for precipitation probability and precipitation intensity of different spectral combinations. Different spectral combinations are used for the construction of the discrimination matrices of the day and the night, respectively. For the day, IR1 (11µm), IR3 (6.7μm), VIS (0.7m), IR12 (TIR2-IR1) and IR13 (TIR3-IR1) are available, among which IR1, VIS and IR3 (or IR13) are mainly used ; for the night, IR1, IR3, IR4 (3.7μm), IR12, IR13, IR14 (TIR4-IR1)and IR24 (TIR4-IR2) are available and IR1, IR3 and IR24 (or IR14) are mainly used. The contrast test between the observed data of precipitation and the retrieval results based on precipitation data from basic stations and reference stations in China in 2007 shows that, 30% precipitation probability can ideally distinguish precipitation area from non-precipitation area; and the analysis of precipitation intensity category also matches well with the fact. It is well known that the observation of satellite is instantaneous one time per hour while the rain gauge observation is an accumulative process during an hour. The error study further suggests that the difference between the two observation methods is the vital cause of the relative error.