In order to improve the accuracy and engineering feasibility of four-Satellite localization system, the frequency difference measurement is introduced to the four-Satellite TDOA (Time Difference of Arrival) localizati...In order to improve the accuracy and engineering feasibility of four-Satellite localization system, the frequency difference measurement is introduced to the four-Satellite TDOA (Time Difference of Arrival) localization algorithm. The TDOA/FDOA (Frequency Difference of Arrival) localization algorithm is used to optimize the GDOP (geometric dilution of precision) of four-Satellite localization. The simulation results show that the absolute position measurement accuracy has little influence on TDOA/FDOA localization accuracy as compared with TDOA localization. Under the same conditions, TDOA/FDOA localization has better accuracy and its GDOP shows more uniform distribution in diamond configuration case. The localization accuracy of four-Satellite TDOA/FDOA is better than the localization accuracy of four-Satellite TDOA.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
针对目前时差定位/频差定位混合无源定位算法存在的定位均方根误差(root mean square error,RMSE)和定位偏差适应测量噪声能力差的问题,提出一种基于泰勒级数展开的非完全约束加权最小二乘法。首先将无源定位问题转化为二次规划问题,简...针对目前时差定位/频差定位混合无源定位算法存在的定位均方根误差(root mean square error,RMSE)和定位偏差适应测量噪声能力差的问题,提出一种基于泰勒级数展开的非完全约束加权最小二乘法。首先将无源定位问题转化为二次规划问题,简化约束条件,应用拉格朗日乘子法求解目标定位的值。然后将得到的解在原约束条件下进行泰勒级数展开,利用获得的结果进一步优化解析解。计算机仿真对比了所提方法和两步加权最小二乘法(two-stage weighted least squares,TSWLS)、改进的约束加权最小二乘法(constrained weighted least squares,CWLS)、基于定位误差修正方法的定位性能,所提算法在兼顾实时性的同时,RMSE和定位偏差均低于TSWLS、CWLS、基于定位误差修正方法。展开更多
By utilizing the time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements of signals received at a number of receivers, a constrained least-square （CLS） algorithm for estimating ...By utilizing the time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements of signals received at a number of receivers, a constrained least-square （CLS） algorithm for estimating the position and velocity of a moving source is proposed. By utilizing the Lagrange multipliers technique, the known relation between the intermediate variables and the source location coordinates could be exploited to constrain the solution. And without requiring apriori knowledge of TDOA and FDOA measurement noises, the proposed algorithm can satisfy the demand of practical applications. Additionally, on basis of con- volute and polynomial rooting operations, the Lagrange multipliers can be obtained efficiently and robustly allowing real-time imple- mentation and global convergence. Simulation results show that the proposed estimator achieves remarkably better performance than the two-step weighted least square （WLS） approach especially for higher measurement noise level.展开更多
Based on the time differences of arrival(TDOA) and frequency differences of arrival(FDOA) measurements of the given planar stationary radiation source, the joint TDOA/FDOA location algorithm which solves the location ...Based on the time differences of arrival(TDOA) and frequency differences of arrival(FDOA) measurements of the given planar stationary radiation source, the joint TDOA/FDOA location algorithm which solves the location of the target directly is proposed. Compared with weighted least squares(WLS) methods,the proposed algorithm is also suitable for well-posed conditions,and gets rid of the dependence on the constraints of Earth's surface. First of all, the solution formulas are expressed by the radial range. Then substitute it into the equation of the radial range to figure out the radial range between the target and the reference station. Finally use the solution expression of the target location to estimate the location of the target accurately. The proposed algorithm solves the problem that WLS methods have a large positioning error when the number of observation stations is not over-determined. Simulation results show the effectiveness of the proposed algorithm, including effectively increasing the positioning accuracy and reducing the number of observatories.展开更多
文摘In order to improve the accuracy and engineering feasibility of four-Satellite localization system, the frequency difference measurement is introduced to the four-Satellite TDOA (Time Difference of Arrival) localization algorithm. The TDOA/FDOA (Frequency Difference of Arrival) localization algorithm is used to optimize the GDOP (geometric dilution of precision) of four-Satellite localization. The simulation results show that the absolute position measurement accuracy has little influence on TDOA/FDOA localization accuracy as compared with TDOA localization. Under the same conditions, TDOA/FDOA localization has better accuracy and its GDOP shows more uniform distribution in diamond configuration case. The localization accuracy of four-Satellite TDOA/FDOA is better than the localization accuracy of four-Satellite TDOA.
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。
文摘针对目前时差定位/频差定位混合无源定位算法存在的定位均方根误差(root mean square error,RMSE)和定位偏差适应测量噪声能力差的问题,提出一种基于泰勒级数展开的非完全约束加权最小二乘法。首先将无源定位问题转化为二次规划问题,简化约束条件,应用拉格朗日乘子法求解目标定位的值。然后将得到的解在原约束条件下进行泰勒级数展开,利用获得的结果进一步优化解析解。计算机仿真对比了所提方法和两步加权最小二乘法(two-stage weighted least squares,TSWLS)、改进的约束加权最小二乘法(constrained weighted least squares,CWLS)、基于定位误差修正方法的定位性能,所提算法在兼顾实时性的同时,RMSE和定位偏差均低于TSWLS、CWLS、基于定位误差修正方法。
基金supported by the National High Technology Research and Development Program of China (863 Program) (2010AA7010422 2011AA7014061)
文摘By utilizing the time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements of signals received at a number of receivers, a constrained least-square （CLS） algorithm for estimating the position and velocity of a moving source is proposed. By utilizing the Lagrange multipliers technique, the known relation between the intermediate variables and the source location coordinates could be exploited to constrain the solution. And without requiring apriori knowledge of TDOA and FDOA measurement noises, the proposed algorithm can satisfy the demand of practical applications. Additionally, on basis of con- volute and polynomial rooting operations, the Lagrange multipliers can be obtained efficiently and robustly allowing real-time imple- mentation and global convergence. Simulation results show that the proposed estimator achieves remarkably better performance than the two-step weighted least square （WLS） approach especially for higher measurement noise level.
基金supported by the National Natural Science Foundation of China(6140236561271300)the 13th Five-Year Weaponry PreResearch Project。
文摘Based on the time differences of arrival(TDOA) and frequency differences of arrival(FDOA) measurements of the given planar stationary radiation source, the joint TDOA/FDOA location algorithm which solves the location of the target directly is proposed. Compared with weighted least squares(WLS) methods,the proposed algorithm is also suitable for well-posed conditions,and gets rid of the dependence on the constraints of Earth's surface. First of all, the solution formulas are expressed by the radial range. Then substitute it into the equation of the radial range to figure out the radial range between the target and the reference station. Finally use the solution expression of the target location to estimate the location of the target accurately. The proposed algorithm solves the problem that WLS methods have a large positioning error when the number of observation stations is not over-determined. Simulation results show the effectiveness of the proposed algorithm, including effectively increasing the positioning accuracy and reducing the number of observatories.
