基于误差时间特性的INS/GNSS观测噪声方差在线计算方法

Study on GNSS Measurement Noise Online Calculation Based on Time-Related Error Characteristics for INS/GNSS Integrated Navigation System

基于INS、GNSS不同误差时间特性,提出了一种组合导航闭环校正下GNSS观测噪声方差阵在线计算方法。该方法的核心是根据惯性导航的短时高精度和GNSS测量噪声的时间不相关性,利用滑动时间窗口内的INS、GNSS增量样本数据之差进行方差统计。结合某次实际飞行数据验证了这种思路的可行性;并利用一组飞行仿真数据验证了该方法对GNSS观测噪声发生变化时能较好的跟踪,且得到更为准确的速度、位置估计值。

A GNSS measurement noises calculating on line method based on the different time-related error characteristics of INS and GNSS was put forward.The core of this method is using the difference incremental sample data at adjacent filtering moments between INS and GNSS,within the sliding time window for variance statistics,according to the short-term high-precision features of INS and the timeunrelated measurement noise of GNSS.The feasibility of this idea was verified by some actual flight data.What’s more,a set of flight simulation data was used to verify that this method can track the variation of GNSS measurement noises well,and obtain more accurate speed and position estimation.