异地遥测对接可行性探究

针对现有飞行器测控系统遥测对接试验周期长、效率低的不足,提出一种异地遥测对接方法.通过构建异地遥测对接系统结构,得到异地遥测对接信号链路模型.基于系统时钟抖动的频率、相位和采样时间表达形式,对异地遥测对接链路中的信号进行了具体推导.在此基础上,从频率和相位2个方面,定量分析了系统时钟抖动对异地遥测对接信号相参性的影响.分析结果表明：对于Ka频段信号,当应答机端异地遥测对接系统的时钟短期频率稳定度优于1×10^-11时,异地遥测对接系统引入的频率抖动△f≤0.6 Hz,相位抖动△φ≤0.075 rad,可认为异地遥测对接信号的相参性不受影响,异地遥测对接可行.

Feasibility of Off-Site TT＆C Compatibility Test for Telemetry

An off-site spacecraft TT＆C （Tracking, Telemetry and Command） compatibility test method for teleme- try is proposed to make up for problems of time-consuming telemetry compatibility test period and low efficiency. A link model of off-site telemetry compatibility test signals is established through construction of the structure of an off-site telemetry compatibility test system. Signals in the links for off-site telemetry compatibility tests are derived based on expressions of clock jitter described in frequency, phase and timing. Furthermore, quantitative analysis is given on the impact of system clock jitter on signal coherence in domains of frequency and phase. The results show that, for Ka band signals, when short term frequency stability of system clock is less than 1 × 10^-11 , signal coher ence will not be affected. In this circumstance, frequency jitter △f is ≤ 0. 6 Hz and phase jitter △φ is ≤ 0. 075 （rad）. In other words, off-site telemetry compatibility tests are feasible.