多GNSS掩星大气探测卫星星座设计

Design of Multi-GNSS Occultation Sounding Satellite Constellation

为减少无线电掩星(RO)大气探测星座的卫星数量并增加探测数据量,将北斗(BD)和GPS、Galileo、GLONASS共同作为探测信源,提出一种多全球导航卫星系统(GNSS)掩星大气探测星座概念和优化设计方法。融合先验大气模型和二维射线追踪算法,建立兼容多GNSS信源的掩星事件前向模拟算法,实现掩星事件快速精确仿真;给出多GNSS掩星大气探测星座参数对探测性能的影响特性,降低了星座模型的复杂度;并利用改进的蚁群算法实现星座参数寻优。设计结果与COSMICII星座相比,卫星数量减少2颗,探测数据量增加了40%,探测均匀性提高了67%。

In order to increase the amount of radio occultation（ RO） atmospheric sounding data and save the number of sounding satellites,a new concept of multi-GNSS（ Global navigation satellite system） sounding constellation with Bei Dou（ BD）,GPS,Galileo and GLONASS is presented,and an optimal design method of such a multi-GNSS RO atmospheric sounding satellite constellation is studied. To realize the radio occultation event simulation fast and accurately,a forward model of multi-GNSS RO sounding is established based on both priori atmosphere model and two-dimensional ray tracing algorithm. The effect of the sounding constellation parameters on the detection performance is completely analyzed to decrease the complexity of the sounding constellation model,and the satisfactory constellation parameters are optimized by using an improved ant colony algorithm. Compared with COSMIC II,the number of sounding satellites is decreased by 2,the amount of soundings is increased by 40% and the uniformity of sounding data is improved by 67%.