北斗卫星定向中参考星的选取研究

卫星定向模型中,参考星的选择直接影响定向解算精度。常用的最大高度角选星法无法使RDOP值达到最优,而通过遍历所有卫星对RDOP值进行排序的方式虽可得到最优RDOP值但计算复杂。针对上述问题,提出了一种基于离散度的参考星选取方法,该方法通过离散度计算选择处于重心位置的卫星作为参考星,能在保证选择最优的情况下兼顾较高的计算效率。通过实验对上述三种方法进行了对比,结果表明,基于离散度的参考星选取方法的RDOP选择最优性远高于最大高度角法,与遍历方式所得的RDOP值一致性可高达82.5%,RDOP值相差在0.2以内的占总体95.6%,且与其解算结果有很高的相关性,但计算复杂度大大降低。

Study of Reference Satellite Selection in BeiDou Satellite Orientation

Analysis the satellite orientation model, the effect of reference satellite selection on directional calculating precision can be learned. The maximum altitude angle satellite is generally selected as the reference satellite, this method is simple in calculation but the RDOP is not the optimal. By traversing all the satellites on RDOP values can obtain the optimal reference satellite but its computational complexity. Regarding the issue above, a reference satellite selection method based on dispersion is proposed, the satellite which is in the gravity center is selected as the reference by the dispersion calculation, and this method has high computational efficiency while ensuring optimal selection. A comparison is made on the three methods through experiments, the results shows that the center method is much higher than the maximum angle method on the optimal height and has high correlation and agreement with traversal resulting on RDOP value, the agreement is up to 82.5%, the D-value of RDOP within 0.2 is up to 95.6% of the total, but it greatly reduce the computational complexity.