针对传统两步定位法在固定无源单站定位精度不高的问题,提出一种基于角速度先验的固定无源单站直接定位方法.首先,给出定位场景及辐射源运动模型,根据雷达辐射源脉内、脉间以及空间采样特点,按照快时间、慢时间、快拍构建三维观测信号模型.将快时间变换至频域并提取一组最强信号,利用本文提出的空时对称自相关函数(Space Time Symmetric Autocorrelation Function,STSAF),消除影响定位精度的多余相位项;然后,将经上述处理的2次观测信号进行混频,构建定位模型并给出直接定位代价函数;同时,针对性提出一种基于位置选择的MUSIC(MUl-tiple SIgnal Classification)算法,根据慢时间域包含的距离信息及空间域包含的方位信息,对辐射源横、纵坐标进行搜索,实现对辐射源的直接定位.本文对算法计算复杂度和克拉美罗下界(Cramer-Rao Lower Bound,CRLB)进行了理论推导,分析了影响定位精度的因素,对比所提直接定位方法与传统两步定位法的均方根误差,绘制本文方法的GDOP(Geometric Dilution Of Precision)曲线.
A Direct Position Determination Method by Fixed Passive Single-Station Based on Prior Angular Velocity
Aiming at the low accuracy of traditional two-step positioning method in fixed passive single station posi-tioning,a fixed passive single station direct positioning method based onprior angular velocity is proposed. Firstly,the posi-tioning scene and radiation source motion model are given. Based on the sampling characteristics of radar radiation source within pulse,between pulse and space,the 3D observation signal model is constructed according to fast time,slow time and snapshot. Secondly,the fast time is transformed into the frequency domain and the strongest set of signals are extracted. By using the STSAF (Space Time Symmetric Autocorrelation Function) function proposed in this paper,the quadratic phase term about the slow time is eliminated. Then,the two observed signals processed above are mixed,the direct location model is constructed and the direct location cost function is given. Meanwhile,an improved MUSIC (MUltiple SIgnal Classifica-tion) algorithm is proposed,which according to the distance information contained in the slow time domain and the azimuth information contained in the space domain,uses the relationship to search the horizontal and vertical coordinates of the radi-ation source to realize the direct location of the radiation source. Finally,this paper quantitatively calculates the computa-tional amount and CRLB (Cramer-Rao Lower Bound) of the algorithm,analyzes the factors that affect the positioning accu-racy,compares the root-mean-square error between the proposed method and the traditional two-step positioning method,and draws the GDOP (Geometric Dilution Of Precision) curve of the proposed method.
fixed passive single-stationdirect position determinationSTSAF functionlocation selection MUSIC
万方数据
维普
