近地卫星GPS接收机降级应用

Degraded Application to LEO Satellite GPS Receiver

针对GPS接收机发生SEL事件后的温度升高问题,在卫星轨道漂移分析基础上,重点考察卫星应答机的AGC电压与载波锁定的温度敏感特性,并确定载波锁定的温度上限,进而提出GPS接收机的降级应用方案,关闭轨道电路板。结果表明,应答机载波锁定时的AGC电压应在0.82V以下,对应卫星应答机温度不超过26.2°C;轨道电路板断电后,GPS接收机定位与守时功能正常,工作温度在20.5°C以下,发生SEL事件的概率降低;GPS接收机温度对于卫星应答机的影响明显减弱,应答机在原有上行约束下的载波锁定时长优于150s,满足上行遥控注入时限需求。降级应用方案已施行于大数量卫星集中监控与管理。

With respect to SEL(Single Event Latch-up)found in GPS(Global Positioning System)receiver of LEO(Low Earth Orbit)satellite,temperature influence after SEL has presented.Details on orbital element shifting are discussed.Satellite transponder is investigated to be thermally sensitized by analyzing AGC(Auto Gain Control)variation and carrier locking characteristic.When transponder AGC is less than0.82V,carrier signal acquisition is reliable with transponder working temperature lower than26.2℃.Degraded application to GPS receiver is carried out to turn off orbital PCB(Printed Circuit Board).The results imply that,after the orbital PCB shutdown,GPS receiver works with normal positioning data and TIC(Time In Continuity)data and temperature below20.5℃,and has a low probability of SEL with mitigation of temperature influence,and satellite transponder is still applicable to obtain carrier signal acquisition time more than150s and is able to fulfill the requirements of telecomm and in the uplink.The Degradation has used in long-term management for lots of satellites on-orbit in TT&C(Telemetry,Tracking and Command).