一种测量非相干扩频应答机时钟准确度的新方法

A New Approach to Measure the Clock Deviation of Noncoherent Spread Spectrum Transponder

简要介绍了扩频测控系统中非相干扩频测距的原理,针对在轨飞行器非相干扩频应答机频率准确度难以准确测量的问题,提出了一种基于星地帧周期固定差统计的卫星时钟准确度的测量方法,编制了下行测量帧解析工具,对卫星实时下传的测量帧数据进行解算,并结合实测距离进行分析处理,推算出应答机实时频率准确度,一定程度上实现了对在轨飞行器时钟系统的健康诊断。

The principle of noncoherent ranging in spread spectrum TT＆C （ Telemetry, Tracking and Com-mand） system is briefly introduced. Since the frequency stability of on-orbit noncoherent spread spectrum transponder is difficult to obtain, a measurement method based on the statistics of fixed satellite-ground frame period error is proposed and related software tool is developed. By using this tool and analyzing the downlink measurement data frame and the measured range data, the frequency stability of the transponder can be deduced and to some extent, the health diagnosis of the transponder’s clock system can be realized.