利用约束加权最小二乘的单站外辐射源时差定位算法

Constrained Weighted Least Squares Algorithm for Single-observer TDOA Location Estimation Using Illuminators of Opportunity

针对利用单个观测接收站接收数个外辐射源信号进行目标定位过程中,传统解析定位算法估计精度不够理想的问题,提出了一种利用约束加权最小二乘(CWLS)到达时差的定位算法。首先将目标到观测接收站的距离作为冗余参量,实现时差观测方程的线性化,然后根据目标到观测接收站的距离与目标位置之间的函数关系,建立为CWLS定位模型,并采用拉格朗日乘子式(Lagrange multiplier)求解该类带约束条件的CWLS问题。同时,还推导了相应的克拉美罗界(CRLB)和理论误差。通过仿真实验和分析可以表明,在存在测量误差的情况下,本文提出的新算法仍然能够逼近CRLB,且与解析方法相比,具有较好的定位精度。

To solve the traditional analytic location methods＇ estimation accuracy is not good enough for the single-observer location using illuminators of opportunity, a constrained Weighted least squares （CWLS） location algorithm based on time differences of arrival is proposed. Firstly, introducing the range from the target to the observer as the additional variable, the TDOA measurement equations are linearized. Considering the relationship between the additional variable and the target location, the location problem is established as a CWLS model. To solve the CWLS model to obtain the estimation of the target position, the solution is derived based on Lagrange multiplier. Finally, the theoretical error and the Cramer Rao Low- er Bound （CRLB） are also derived. Simulation results show that the proposed algorithm approaches the CRLB at high noise level, and comparing with traditional analytic location method, it has a better estimation accuracy.