两步法快速解算编队卫星GPS模糊度

为克服卫星编队飞行实时相对定位中双频模糊度解算速度慢的缺点,结合扩展Kalman滤波(EKF,Extended Kalman Filter),首先采用少数个历元(如10个)相位平滑伪距相对定位结果与 L₆的平均值对滤波初始化,再根据两步法解算双频模糊度,即先解算并正确固定宽巷模糊度,获得较准确的基线分量估值,然后采用选权拟合方法,将基线分量作为约束条件解算并固定双频模糊度.仿真算例计算结果表明,当宽巷模糊度正确固定后,编队卫星间相对定位误差在5cm以内,两步法可以在较短时间(约3min)内固定双频模糊度,为精确解算编队卫星的相对状态提供保障.

Rapid resolution of GPS ambiguities of satellite formation flying with two-step method

In order to rapidly resolve the carrier ambiguities of satellite formation flying, a two-step method combined with extended Kalman filter (EKF) was proposed. The first step is to fix the wide-lane ambiguities during the state estimation after initializing the filtering with carrier-smoothed-code algorithm and mean value of L_6. The second step is to calculate the float double-frequency ambiguities with the method of selecting the parameter weights using the baseline component as a constraint. The simulated case reveales that the baseline accuracy is within 5 cm after the wide-lane ambiguity was solved and the proposed method can correctly resolve the ambiguities within 3 minutes after the filtering initialization with 10 epochs observation.