风场测量雷达是我国风云系列气象卫星的第一部主动遥感仪器，是国际上第一部星载双频双极化散射计，采用先进的扇形波束圆锥扫描体制，通过地球系统的后向散射测量获取全球海面风场、土壤湿度和海冰覆盖等地球物理参数。本文介绍了风场测量雷达的测量原理、信号特性与主要性能指标，给出了风场测量雷达数据预处理方法；根据卫星发射后的测试数据，初步分析了仪器在轨工作性能。分析结果表明，风场测量雷达在轨状态良好，性能指标达到预期，为其数据的遥感应用、同化应用与天气预报奠定了基础。

The Wind Radar (WindRAD) onboard Fengyun-3E (FY-3E) meteorological satellite is the first active remote sensing instrument of China"s Fengyun series satellites and the first spaceborne dual frequency & dual polarization scatterometer in the world. Spaceborne scatterometer is important remote sensing instrument for measuring meteorological and ocean parameters, which obtains geophysical parameters such as wind speed and wind direction on the global ocean surface through backscattering measurement of the earth system. WindRAD uses the advanced fan beam with conical scanning system, mainly aiming at measuring the sea surface wind vector all weather and all day with high precision as well as high resolution. In addition, the WindRAD can also measure soil moisture, sea ice and other geophysical parameters. This paper aims to give the preliminary evaluation of in-orbit performance for the WindRAD. The observation principle, signal characteristics and main performance indicators of the WindRAD are introduced, and the detailed data preprocessing method is proposed, that is, the level 1 processing to generate backscattering coefficient of global land and sea surface. According to WindRAD’s in-orbit test after the launch in 2021, the performance of the instrument is preliminarily analyzed. Key telemetry parameters including rotation speed, internal calibration value and temperatures of important components are analyzed. Azimuth resolution, range resolution, observation swath width, radiometric resolution, and internal calibration accuracy are evaluated using WindRAD actual remote sensing data as well as parameters measured before the launch. The analysis results show that WindRAD works steadily in orbit, all of the performance indicators meet the expectations, and can provide high-quality backscattering coefficient data in both C and Ku bands for product retrieval. This work paves the way for WindRAD remote sensing application, assimilation application and weather forecast. WindRAD observation data is received and processed in FY-3E satellite ground system. The operational data is public to the users worldwide and can be obtained from the FENGYUN Satellite Data Center of National Satellite Meteorological Center, China Meteorological Administration (http://satellite.nsmc.org.cn/PortalSite/Data/DataView.aspx).