用户星高度对中继卫星星间链路的性能影响

数据中继卫星(简称中继星)系统可为各种用户星提供优质服务,但用户星轨道高度严重影响了中继星与用户星之间的星间链路(IOL)性能。文章通过数学模型来计算IOL自由空间损耗的极值和中继星星间天线的视场角,并用STK进行了仿真验证。基于此模型,对近地圆轨道航天器和导航卫星两种用户进行了实例分析。发现对近地圆轨道用户星,自由空间损耗的最大值与最小值之差和天线视场角均不大,设计时不需要特别考虑;而对导航卫星用户,两项参数值分别高达15dB和大于35°,需采用相应措施来避免过设计和解决视场角大的问题。

Effects of User Altitude on the Performance of DRS Inter-orbit Communications Link

Data relay satellite(DRS) system can provide excellent services to various user spacecrafts,but the inter-orbit link(IOL)between DRS and user is obviously influenced by user's altitude.The effects of circular orbit spacecraft altitude on the performance of IOL were analyzed.A mathematical model was established to calculate the extreme values of free-space loss and DRS′s IOL antenna field angle,followed by simulation demonstrations with STK6.1.Based on the mathematical model,two instances of low earth circular orbit(LEO)spacecraft and navigation satellite were given respectively.For LEO users,the extreme Lf difference is less than 4dB and antenna field angle is within ±13° to which there is no need to pay attention during design,while for navigation satellite user,they are 15dB and larger than 35°which result that some relevant methods should be adopted to prevent over-design and antenna with large field angle should be employed on DRS.