融合CYGNSS和SMAP卫星数据监测飓风强度

Measurement of hurricane intensity by fusing CYGNSS and SMAP satellite data

摘要:

为提高海洋飓风强度的观测频次和测量准确度,对综合利用热带气旋全球导航卫星系统（CYGNSS）和土壤湿度主动-被动探测（SMAP）卫星数据监测飓风强度进行了研究.首先,介绍了卫星数据特征；然后,以佛罗伦萨飓风为例,提出了融合这两种卫星数据监测海洋飓风强度的方法,其中包括卫星数据预处理、基于像素级影像融合方法的高风速区域提取和飓风强度测量；最后,将融合两种卫星数据测得的10场飓风的强度与美国国家飓风中心(NHC)提供的飓风最大风速值进行对比分析,并采用平均绝对误差、均方根偏差和相关系数3个指标评价这两种风速测量结果之间的差异.结果表明:与仅利用SMAP卫星数据相比,本文方法能以更高的频次监测飓风强度,可获得更加完整的飓风高风速区域；与美国国家飓风中心提供的飓风最大风速值相比,本文方法监测飓风强度结果的平均绝对误差变动范围为3.9～10.2 m/s,均方根偏差变动范围为4.6～12.5 m/s,相关系数变动范围为0.570 7～0.915 2,验证了提出的海洋飓风强度监测方法的有效性.

Abstract:

To improve the frequency and accuracy for measuring ocean hurricane intensity, a joint use of cyclone global navigation satellite system (CYGNSS) and soil moisture active and passive (SMAP) satellites data to measure the hurricane intensity was investigated. First, the satellite data characteristics were introduced. Then, taking Hurricane Florence as an example, a method was proposed by fusing the satellite data to measure the ocean hurricane intensity, including the preprocessing of satellite data, the extraction of high wind speed area using a pixel-level data fusion method, and the measurement of hurricane intensity. Finally, the observation results of ten hurricanes were compared with the highest wind speed measured by the American National Hurricane Center (NHC). The root-mean-square difference, mean absolute error, and correlation coefficient were adopted to analyze the differences among the wind speed measurement results. Results demonstrate that compared with the case of the SMAP satellite data, the proposed method could measure the hurricane intensity at more frequent intervals, and more complete high wind speed area was obtained. The comparison between the hurricane intensity obtained using the proposed method and measured by NHC shows that the mean absolute error ranged between 3.9 and 10.2 m/s, the root-mean-square difference varied between 4.6 and 12.5 m/s, and the correlation coefficient ranged between 0.570 7 and 0.915 2, which confirms the effectiveness of the proposed method in measuring hurricane intensity.