对于空中机动平台,观测站位置误差的存在,使得传统时差定位方法的精度不能满足高精度定位需求。针对观测站位置误差下的多站时差定位问题,提出一种基于观测站精确距离信息的高精度时差定位方法。不同于传统的两步加权最小二乘(two step weighted least squares,TS-WLS)算法,该算法在加权最小二乘时直接对目标位置估计的误差进行估计,避免了开方、平方等非线性运算。仿真实验结果表明,引入观测站精确距离信息能够大幅提升目标定位精度,所提算法具有较强的噪声适应能力,能够在观测站位置误差较大的情况下实现高精度时差定位。
Positioning method using time difference measurements from multi-station based on precise distance information of observation stations
For aerial maneuvering platforms,the presence of observation stations position errors makes the positioning accuracy of traditional time difference positioning methods unable to meet the high-precision positioning requirements.In view of the problem of multi-station time difference positioning with observation stations position errors,a high-precision time difference positioning method based on precise distance information of observation stations is proposed.Unlike the traditional two step weighted least squares(TS-WLS)algorithm,the proposed algorithm directly estimates the error of target position estimation in weighted least squares step,avoiding nonlinear operations such as square and square root.Simulation experiment results show that introducing precise distance information from observation stations can significantly improve the accuracy of target positioning and the proposed algorithm has strong noise adaptability and can achieve high-precision time difference positioning in the case of large observation station position errors.
time difference of arrival(TDOA)two step weighted least squares(TS-WLS)Taylor series expansionpseudo-linear equation