1米C-SAR-01业务卫星海面风反演能力初步评估

Preliminary Evaluation of Sea Surface Wind Retrieval Capability of 1 Meter C-SAR-01 Operational Satellite

2021年11月23日,中国首颗C波段合成孔径雷达业务卫星1米C-SAR-01星成功发射,标志着我国海洋遥感业务化观测能力的进一步提升。为了验证1米C-SAR-01业务卫星的海面风场反演能力,本文介绍了C波段合成孔径雷达风场反演方法,给出了1米C-SAR-01卫星风场反演的初步结果。1米C-SAR-01卫星风速和风向反演的初步精度评估是根据欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)发布的ERA5再分析数据进行的。采集了2022年3月14日至16日共168景全极化影像作为数据基础,共匹配到714个风单元,并基于VV极化下的4种地球物理模型函数(Geophysical Model Function,GMF)以及HH极化下的8种极化比(Polarization Ratio,PR)模型和CMODH模型进行精度评估。结果显示风速和风向的均方根误差(RMSE)分别为0.90 m/s和12.31°。讨论了不同地球物理模型函数和极化比模型的不同性能,表明,1米C-SAR-01卫星具有较好的风场反演能力。

On November 23,2021,China's first C-band synthetic aperture radar service satellite,1 Meter CSAR-01 satellite,was successfully launched,marking the further improvement of China's Marine remote sens⁃ing service observation capability.In order to verify the sea surface wind retrieval capability of the 1 Meter CSAR-01 satellite,the wind field retrieval methods of C-band synthetic aperture radar are introduced and the preliminary results of wind field retrieval of the 1 Meter C-SAR-01 satellite are showen in this study.The ini⁃tial accuracy assessment of wind speed and wind direction inversion for the 1 Meter C-SAR-01 satellite is based on ERA5 reanalysis data published by the European Centre for Medium-Range Weather Forecasts(ECMWF).With a total of 168 quad-polarized images being collected from March 14 to 16,2022 to be used as the database and a total of 714 wind elements being matched,the accuracy was evaluated based on 4 Geophysical Model Functions(GMF)under VV-polarization,8 Polarization Ratio(PR)models and CMODH model under HHpolarization.The results show that the Root Means Square Error(RMSE)of wind speed and direction are 0.90 m/s and 12.31°respectively.The differences between the performance of Geophysical Model Function(GMF)and Polarization Ratio(PR)are also discussed,which shows that the 1 Meter C-SAR-01 satellite has good wind field retrieval capability.