多普勒积分时长对星间测速精度影响分析

Analysis of Inter-satellite Velocity Measurement Accuracy Influenced by Doppler Integral Time

针对大动态星间速度精确测量问题,文章提出了测量环路多普勒积分时长的设计方法。在获得具体双星星座两颗卫星之间的相对运动速度变化规律的基础上,研究建立不同多普勒变化率积分区间时长情况下的星间速度测量误差数学关系,并进行编程数值计算。通过数值分析和测试结果对比表明:在不同积分区间时长情况下,星间速度测量误差仿真结果与设备实际测试结果一致。多普勒积分时间为200 ms时的星间速度测量误差为±1.4 m/s,通过缩短积分时间长度,可以将星间速度测速误差减小到[-0.14 m/s,+0.14 m/s]以内,达到了预期效果。该方法可应用于星座项目星间速度测量精度指标预算设计工作中进行多普勒积分时长的选择。

Aiming at the precise measurement of highly dynamic satellite velocity, the design method of measuring loop Doppler integral time is proposed. On the basis of obtaining the change law of relative velocity between two satellites in a specific binary constellation, the mathematical relationship of inter-velocity measurement error with different duration of Doppler rate integration interval is studied and programmed for numerical calculation. By comparing the numerical analysis with the actual test results, it shows that the inter-satellite velocity measurement errors are consistent with the physical equipment test results under the condition of different integral intervals. When the Doppler integral time is 200 ms, the inter-satellite velocity measurement error is ±1.4 m/s. By shortening the integral time, the inter-satellite velocity measurement error can be deduced to within [-0.14 m/s,+0.14 m/s], fulfilled the desired result. The method introduced in this paper can be applied to select the Doppler integral time length in the budget of inter-satellite velocity measurement accuracy for constellation projects.