嫦娥四号着陆器定向中继链路指向及盲捕策略

Pointing and Blind Capture Strategy of Directional Relay Link for Chang’e-4 Lander

嫦娥四号任务中,着陆器通过定向中继链路,向"鹊桥"中继卫星发送数传数据.为了实现窄波束定向天线对中继卫星的实时指向控制,制定了嫦娥四号中继任务的定向中继链路指向控制策略.同时,针对由于窄波束天线指向误差、着陆器着陆姿态误差以及故障情况下无法获知自身位置、姿态等问题而导致的中继链路丢失问题,制定了中继链路盲捕策略.文章论述了策略制定的依据、分析过程及实现流程,对此策略在嫦娥四号在轨任务中的实际应用和验证进行了总结.

In the Chang,e-4 mission,the lander transmits telemetry and data to the QueQiao satellite through a directional relay link.In order to realize the real-time pointing control of the relay satellite with narrow beam HGA(High Gain Antenna),a pointing control strategy is designed in this paper.At the same time,aiming at the relay link loss caused by narrow-beam antenna pointing error,landing attitude error of lander,the relay link blind beam capture stategy is formulated.In this paper,the design of directional process of the strategies for ralay fixed link is described.The basis,analysis process and implementation process of the strategy are described.At last,the practical application and verification of the strategy in Chang’e-4 on-orbit mission are summarized.