WGS-84 坐标系下双机纯角度无源定位及性能分析
Performance analysis of passive location by two airborne platforms with angle-only measurements in WGS-84
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摘要: 为实现切合实际的多运动平台对辐射源的无源定位,提出了基于WGS-84坐标系的双机纯角度交叉定位方法。推导了在各自平台坐标系下的视线(line-of-sight, LOS)到公共的WGS-84坐标系的旋转变换矩阵,然后应用空间两异面直线公垂线线段中点实现纯角度交叉定位;同时,利用一阶Taylor展开法,推导了误差经旋转变换和交叉定位等非线性变换后的协方差矩阵,并将其用于对多个单次定位估计的滤波,以提高算法定位精度。通过仿真,对影响定位精度的主要因素进行了深入分析,对比研究了单次定位和滤波定位性能,结果表明后者可明显改善精度,验证了该方法的有效性,得到的结论可指导实际运用。Abstract: In order to realize passive location to an emitter by multiple moving platforms practically, a cross location with angle-only measurements by two airborne platforms based on WGS-84 coordinate system was proposed. These rotational matrix used to transform line-of-sight from each own platform's coordinate system to common WGS-84 were derived,and then angle-only cross location was achieved as the midpoint of common perpendicular line segment of two lines on different planes. At the same time, using the 1st order Taylor expansion method, the error covariances by nonlinear transform of rotation and cross location were derived which were used to filter a number of single position estimations to improve positioning accuracy. By simulation, the main factors which affected positioning accuracy were analyzed in-depthly, and the performance of single time location and by filtering were studied contrastively. The results show the latter can improve precision obviously, and indicate the validation of the algorithm. The conclusion can guide practical application.