风云三号卫星的定量遥感应用能力
Quantitative Remote Sensing from the Current Fengyun 3 Satellites
中文摘要：
风云三号（FY-3）是我国第二代极轨气象卫星，目前已经形成了上下午星的组网观测能力。同第一代风云一号卫星相比，风云三号实现了光谱覆盖紫外、可见光、红外和微波的多遥感仪器综合观测。详细介绍了风云三号在宽刈幅光学成像、大气垂直结构探测、微波成像、大气成分探测和地球辐射收支监测等方面观测能力的改进和提高，展示了一些典型的应用个例，最后针对新型极轨气象卫星资料讨论了开展定量遥感工作需要关注的问题。
中文关键词：
风云三号，气象卫星，定量遥感
KeyWords：
FY-3, meteorological satellite, quantitative remote sensing
Abstract：
The Fengyun 3 (FY-3) series is the second generation of Chinese sun-synchronous meteorological satellites. The first two of them were successfully launched in 2008 and 2010 separately. In comparison with the first generation FY-1 series, FY-3 has improved the global observation including optical imaging capacity from kilometre to hundred-metre resolution, passive microwave imaging, atmospheric temperature and moisture sounding, atmospheric chemistry remote sensing, and Earth radiation budget measurement with 11 payloads on board. This paper introduces elementary observations from FY-3A and FY-3B as well as the data utilization. The examples show the excellent performance of FY-3 measurements in weather scale analysis, numerical weather prediction, elementary climate variables monitoring, global environment and disaster monitoring. The optical imager, Medium Resolution Spectral Imager (MERSI) can provide true-colour composite images with three RGB channels in 250 m spatial resolution globally every day so that MERSI possesses more advanced properties in global environment and disaster monitoring with a better image texture and image lamination. The microwave imager, MicroWave Radiation Imager (MWRI) can penetrate most non-precipitating clouds to retrieve the surface properties in all weather conditions with lower-frequency channels. In addition, higher-frequency channels of MWRI are a good indicator to detect rainfall over both land and ocean. The atmospheric sounding system is composed of three instruments, i.e., InfraRed Atmospheric Sounder (IRAS), MicroWave Temperature Sounder (MWTS) and MicroWave Humidity Sounder (MWHS). Data from the FY-3 sounding system have been introduced into the ECMWF Integrated Forecasting System to assess the data quality and the influence of the data on analyses and forecasts. The analysis of first-guess departures has shown data with high quality overall. The FY-3 sounding data contribute positively to NWP model forecasting. The atmospheric chemistry mission provides a total ozone amount, ozone profile from Total Ozone Unit (TOU) and Solar Backscatter Ultraviolet Sounder (SBUS). The Earth radiation budget mission provides the incoming solar irradiance and the outgoing long-wave radiance at the top of atmosphere from Earth Radiation Measurement (ERM) and Solar Irradiance Monitor (SIM). The morning orbit satellite FY-3A and the afternoon orbit satellite FY-3B have constituted the polar constellation to provide global observation of the Earth four times per day operationally. They are becoming an important component of the space-based global observing system.
Although great progress has been achieved, the quantitative remote sensing and products utilization of FY-3 satellites are still challenging. To deepen the demonstration of FY-3 data, the theoretical study on the atmospheric radiation transfer, the radiometric and spectrometric calibration, the validation of the retrieved products should be further strengthened. The potential application of polar orbiting satellite in weather analysis, climate change research should be made with acceleratory efforts.
Although great progress has been achieved, the quantitative remote sensing and products utilization of FY-3 satellites are still challenging. To deepen the demonstration of FY-3 data, the theoretical study on the atmospheric radiation transfer, the radiometric and spectrometric calibration, the validation of the retrieved products should be further strengthened. The potential application of polar orbiting satellite in weather analysis, climate change research should be made with acceleratory efforts.