数据择优合成在气象卫星路径分集中的应用

Application of data merit synthesis in meteorological satellite path diversity

针对降雨对风云四号静止气象卫星Ka频段数传链路造成的影响和数据路径分集接收情况,对主站和分集站的数据进行择优合成,以减少降雨衰减对数据造成的损失,为用户分发“最佳”数据。本文采用国际电信联盟无线电通信部门(ITU-R)提供的雨天衰减预算模型对降雨衰减情况进行了充分计算,设计了数据择优合成系统,通过高级在轨系统(AOS)帧数据的填充及误码等情况对数据质量进行判别、并逐帧选取高质量数据进行合成,分发给用户。由于降雨对不同频段的信号衰减效果不同,在业务环境中利用Ka频段和X频段数据对本系统进行了模拟测试。经测试,数据择优合成系统能够对输入数据的质量进行有效判断并生成符合业务需求的分发数据,有效减少了降雨对Ka频段数据造成的影响。结果表明,数据择优合成系统能够在路径分集中充分发挥作用,保障气象卫星数据的高质量接收和Ka频率资源的使用。

In order to reduce the loss of data due to rainfall attenuation and to provide the "best" data for users, the master and diversity data in the path diversity reception mode are optimally synthesised to reduce the impact of rainfall on the Ka-band data transmission link of the Fengyun-4 geostationary meteorological satellite. In this paper, the rainfall fading budget model provided by the International Telecommunication Union′s Radiocommunication Sector(ITU-R) is used to fully calculate the rainfall fading situation, and a data merit synthesis system is designed to discriminate the data quality by the fill and error codes of the Advanced Orbiting Systems(AOS) frame data, and to select high-quality data frame by frame for synthesis and distribution to users. Because of the different attenuation effects of rainfall on different frequency bands, the system was tested in a simulated operational environment using Ka-band and X-band data. The test showed that the data merit synthesis system was able to effectively judge the quality of the input data and generate distribution data that met the service requirements, effectively reducing the impact of rainfall on the Ka-band data. The results show that the data merit synthesis system can fully play its role in the path subset, ensuring the high-quality reception of meteorological satellite data and the use of Ka frequency resources.