FY-3E Wind Scatterometer Prelaunch and Commissioning Performance Verification

The spaceborne microwave scatterometer (SCAT) is a radar for quantitatively measuring the backscatter coefficient of the Earth's surface. Its main application is the measurement of wind speed and direction near the sea surface with a wide swath and high precision. So far, many SCATs have been launched in orbit, including SeaWinds by the United States, the advanced scatterometer (ASCAT) series by Europe, and the HY-2 series scatterometers by China, which contribute to improved weather forecasts and typhoon positioning services. The Fengyun-3E (FY-3E) satellite wind scatterometer or WindRad, launched by China in July 2021, is the first Ku and C dual-band SCAT with the highest spatial resolution. In this study, the rotation characteristics and calibration parameters of WindRad in the prelaunch stage and after its early test and verification in orbit were investigated. The prelaunch test results demonstrated the excellent performance of WindRad, which can fully meet its quantitative application requirements. In-orbit early tests demonstrated the stable operation of WindRad, with signal characteristics consistent with the design specifications. The Ku and C dual-band earth surface backscatter coefficient projection and the sea surface wind field inversion were also investigated. The preliminary results confirmed the ability of WindRad to provide a high-quality ocean wind measurement and the improved capability for different applications, including sea ice detection and soil moisture measurement.

Automated summary

The spaceborne microwave scatterometer (SCAT) is a radar used to quantitatively measure the backscatter coefficient of the Earth's surface. It is mainly used for wide-swath and high-precision measurement of wind speed and direction near the sea surface. Various SCATs have been launched, contributing to improved weather forecasts and typhoon positioning services. The recent launch of China's WindRad, the first Ku and C dual-band SCAT, demonstrates its excellent performance in prelaunch and in-orbit tests, showing its capabilities for high-quality ocean wind measurement and improved applications.