基于长时间序列ASAR数据的近海风场反演  

Measurement of Offshore Sea Surface Winds Using Long Time Series Data of ASAR

作　　者：张康宇 王苏娟[2] 郭乔影[1] 李正泉[3] 韩冰[1] 王秀珍[2] 黄敬峰[1] 

机构地区：[1]浙江大学遥感与信息技术应用重点实验室,浙江杭州310058 [2]杭州师范大学遥感与地球科学研究院,浙江杭州311121 [3]浙江省气候中心,浙江杭州310007

出　　处：《遥感技术与应用》2016年第6期1059-1068,共10页Remote Sensing Technology and Application

基　　金：公益性行业(气象)科研专项"多源测风资料融合技术研究及其在风能资源评估中的应用"(GYHY201306050);浙江省科技计划项目"近海面风场遥感协同反演方法研究及其应用"(2013C33068)

摘　　要：首先获取覆盖浙江省近海215景长时间序列多模式ASAR Level 1B数据,对获取的ASAR数据进行几何校正、辐射定标、极化比转化、噪声剔除后,将所有的影像统一重采样得到1km×1km分辨单元的后向散射系数影像,尝试利用CCMP风向作为SAR风速反演地球物理模式函数的风向初始场,对比目前国际上最常用的3种模式函数CMOD4、CMOD-IFR2和CMOD5的风速反演效果,将反演得到风速分别与CCMP插值风速和现场观测气象站点的风速进行对比,结果表明CCMP风向数据可作为SAR风速反演的风向初始场,其中结合CMOD4模式函数能够得到较高精度的反演风速,由于CCMP数据有效时间长、覆盖范围广、易于获取,因此联合CCMP风向有利于SAR近海风场反演的业务化应用。Firstly, obtaining 215 long time series ASAR Level 1B data which are from different ASAR meas- urement modes. After the process of geometric rectification, radiometric calibration, polarization conver- sion, noise removal,image resampling,converting all the Level 1B data into the normalized radar backscat- ter coefficient images with the same pixel spacing of 1 kmX 1 km.Secondly,wind directions from cross-cal- ibrated muti-platform （CCMP） were used as the initial wind directions to retrieve wind speeds from SAR images by using three most commonly used geophysical model functions （GMF）：CMOD4, CMOD-IFR2, CMOD5. The comparison of wind speeds retrieved from SAR with interpolated CCMP wind speeds and with in-situ meteorological stations wind speeds showed that wind directions from CCMP could be used as the initial wind directions for wind retrieval using SAR images,and using CMOD4 mode function could get the highest accuracy retrieval wind speeds.Since CCMP data valid for a long time,covering a wide range and easily accessible,the combination of CCMP wind direction and SAR images have an advantage for opera- tional wind field retrieval in the future,a useful try has been carried out in this experiment.

关 键 词：SAR CCMP 海面风场 

分 类 号：P732[天文地球—海洋科学]