基于子协方差阵加权的三星时差定位数据综合

Data integration based on sub-covariance weighting for a three-satellite TDOA-based location system

为提高三星时差定位系统的定位精度,需要将系统在不同时间得到的多个定位估计结果进行统计综合。本文提出了一种基于子协方差阵加权的定位数据综合算法。该算法根据单点定位精度分析结果,先利用定位误差协方差的二维子阵的逆矩阵作为权矩阵,通过加权最小二乘估计目标空间三维坐标位置中的其中两维,再利用WGS-84地球模型求解另一维坐标。仿真实验表明,相比已有算法,所提新算法可以明显提高定位精度。

To integrate multiple location estimates obtained at different time instants by a three-satellite TDOA-based passive location system,a method based on sub-covariance weighting is proposed.Based on the outcomes of the location precision analysis of a single estimate,the algorithm yields an integrated estimate of the spatial location through a two-step process： firstly,by using the inverse of the sub-covariance as the weighting matrix,it estimated two of the three coordinates through weighted least square（WLS）;secondly,it calculated the last one coordinate by solving the WGS-84 ellipsoid model function of the earth.Simulations show that the proposed method,compared with the existing methods,can significantly increase the location precision,.