The source location based on the hybrid time difference of arrival(TDOA)/frequency difference of arrival(FDOA) is a basic problem in wireless sensor networks, and the layout of sensors in the hybrid TDOA/FDOA position...The source location based on the hybrid time difference of arrival(TDOA)/frequency difference of arrival(FDOA) is a basic problem in wireless sensor networks, and the layout of sensors in the hybrid TDOA/FDOA positioning will greatly affect the accuracy of positioning. Using unmanned aerial vehicle(UAV) as base stations, by optimizing the trajectory of the UAV swarm, an optimal positioning configuration is formed to improve the accuracy of the target position and velocity estimation. In this paper, a hybrid TDOA/FDOA positioning model is first established, and the positioning accuracy of the hybrid TDOA/FDOA under different positioning configurations and different measurement errors is simulated by the geometric dilution of precision(GDOP) factor. Second, the Cramer-Rao lower bound(CRLB) matrix of hybrid TDOA/FDOA location under different moving states of the target is derived theoretically, the objective function of the track optimization is obtained, and the track of the UAV swarm is optimized in real time. The simulation results show that the track optimization effectively improves the accuracy of the target position and velocity estimation.展开更多
利用到达时间差(Time Difference of Arrival,TDOA)和到达频率差(Frequency Difference of Arrival,FDOA)对移动目标进行定位是现代电子战争的重要课题。传统的定位算法由于TDOA/FDOA参数与目标参数存在非线性关系,求解困难且存在初值...利用到达时间差(Time Difference of Arrival,TDOA)和到达频率差(Frequency Difference of Arrival,FDOA)对移动目标进行定位是现代电子战争的重要课题。传统的定位算法由于TDOA/FDOA参数与目标参数存在非线性关系,求解困难且存在初值与收敛性问题。为此提出一种结合两步加权最小二乘法(Two-Stage Weighted Least Squares,TSWLS)与偏差补偿的定位算法,这种结合算法先建立一组关于TDOA与FDOA的线性方程,再利用泰勒级数展开算法线性化中间变量,计算偏差值,用线性方程的解减去偏差值得到最终解,算法的解为闭式解不存在收敛问题。仿真证明,结合算法优于传统TSWLS算法,在低噪声环境下可以达到克拉美罗界(Cramér-Rao Lower Bound,CRLB),同时在大噪声环境下也能保持良好的鲁棒性,且目标距离越近,观测点阵的大小越大,定位性能越好。展开更多
针对多星定位系统对地面静态目标的无源定位误差分析问题,运用Fisher信息矩阵、Taylor级数、矩阵理论和统计理论,综合考虑时差、频差、卫星位置误差以及卫星速度误差,推导了到达时间差(time difference of arrival,TDOA)/到达频率差(fre...针对多星定位系统对地面静态目标的无源定位误差分析问题,运用Fisher信息矩阵、Taylor级数、矩阵理论和统计理论,综合考虑时差、频差、卫星位置误差以及卫星速度误差,推导了到达时间差(time difference of arrival,TDOA)/到达频率差(frequency difference of arrival,FDOA)联合定位误差克拉美·罗界(Cramer-Rao lower bound,CRLB)的简单表达式,以及三星单独TDOA定位误差的CRLB,进而给出了避免TDOA定位盲区的良好卫星构型设计的充分条件.理论分析与仿真结果表明:在单独TDOA定位场景下良好的构型能完全消除定位盲区,定位精度随主星-星下点连线与主星-副星连线的夹角逼近90°而逐渐提高;通过引入FDOA与TDOA联合定位也能有效避免定位盲区,提高定位精度.展开更多
由于现有的基于最大比合并MRC(Maximum Ratio Combination)的联合搜索定位算法实现复杂度高,为降低其计算复杂度,提出基于网格搜索的加权最大似然代价函数定位算法WMLGS(Weighted ML Grid Search Localization)。仿真结果表明:MRC和WMLG...由于现有的基于最大比合并MRC(Maximum Ratio Combination)的联合搜索定位算法实现复杂度高,为降低其计算复杂度,提出基于网格搜索的加权最大似然代价函数定位算法WMLGS(Weighted ML Grid Search Localization)。仿真结果表明:MRC和WMLGS算法的定位性能近似相等,在无地球表面约束条件下均优于单独时差或频差定位性能,并且逼近克拉美罗联合界,同MRC相比,WMLGS节省了一半左右的计算量,因此更具有实用价值。展开更多
基金supported by the National Natural Science Foundation of China (61502522)Equipment Pre-Research Field Fund(JZX7Y20190253036101)+1 种基金Equipment Pre-Research Ministry of Education Joint Fund (6141A02033703)Hubei Provincial Natural Scie nce Foundation (2019CFC897)。
文摘The source location based on the hybrid time difference of arrival(TDOA)/frequency difference of arrival(FDOA) is a basic problem in wireless sensor networks, and the layout of sensors in the hybrid TDOA/FDOA positioning will greatly affect the accuracy of positioning. Using unmanned aerial vehicle(UAV) as base stations, by optimizing the trajectory of the UAV swarm, an optimal positioning configuration is formed to improve the accuracy of the target position and velocity estimation. In this paper, a hybrid TDOA/FDOA positioning model is first established, and the positioning accuracy of the hybrid TDOA/FDOA under different positioning configurations and different measurement errors is simulated by the geometric dilution of precision(GDOP) factor. Second, the Cramer-Rao lower bound(CRLB) matrix of hybrid TDOA/FDOA location under different moving states of the target is derived theoretically, the objective function of the track optimization is obtained, and the track of the UAV swarm is optimized in real time. The simulation results show that the track optimization effectively improves the accuracy of the target position and velocity estimation.
文摘利用到达时间差(Time Difference of Arrival,TDOA)和到达频率差(Frequency Difference of Arrival,FDOA)对移动目标进行定位是现代电子战争的重要课题。传统的定位算法由于TDOA/FDOA参数与目标参数存在非线性关系,求解困难且存在初值与收敛性问题。为此提出一种结合两步加权最小二乘法(Two-Stage Weighted Least Squares,TSWLS)与偏差补偿的定位算法,这种结合算法先建立一组关于TDOA与FDOA的线性方程,再利用泰勒级数展开算法线性化中间变量,计算偏差值,用线性方程的解减去偏差值得到最终解,算法的解为闭式解不存在收敛问题。仿真证明,结合算法优于传统TSWLS算法,在低噪声环境下可以达到克拉美罗界(Cramér-Rao Lower Bound,CRLB),同时在大噪声环境下也能保持良好的鲁棒性,且目标距离越近,观测点阵的大小越大,定位性能越好。
文摘针对多星定位系统对地面静态目标的无源定位误差分析问题,运用Fisher信息矩阵、Taylor级数、矩阵理论和统计理论,综合考虑时差、频差、卫星位置误差以及卫星速度误差,推导了到达时间差(time difference of arrival,TDOA)/到达频率差(frequency difference of arrival,FDOA)联合定位误差克拉美·罗界(Cramer-Rao lower bound,CRLB)的简单表达式,以及三星单独TDOA定位误差的CRLB,进而给出了避免TDOA定位盲区的良好卫星构型设计的充分条件.理论分析与仿真结果表明:在单独TDOA定位场景下良好的构型能完全消除定位盲区,定位精度随主星-星下点连线与主星-副星连线的夹角逼近90°而逐渐提高;通过引入FDOA与TDOA联合定位也能有效避免定位盲区,提高定位精度.
文摘由于现有的基于最大比合并MRC(Maximum Ratio Combination)的联合搜索定位算法实现复杂度高,为降低其计算复杂度,提出基于网格搜索的加权最大似然代价函数定位算法WMLGS(Weighted ML Grid Search Localization)。仿真结果表明:MRC和WMLGS算法的定位性能近似相等,在无地球表面约束条件下均优于单独时差或频差定位性能,并且逼近克拉美罗联合界,同MRC相比,WMLGS节省了一半左右的计算量,因此更具有实用价值。
