纯方位二维运动目标的不可观测性问题研究

Research on the Unobservability Problem for Two-Dimensional Tracking Based on Bearings-Only Measurements

纯方位系统是可观测的 ,是指系统在纯方位观察条件下 ,能唯一地求解出目标的运动参数。针对二维空间作匀加速运动的目标 ,对纯方位系统跟踪的不可观测性问题进行了讨论。证明了在观测器保持匀速直线运动时 ,纯方位系统定位与跟踪不可求解这一命题。对于利用被动传感器得到的纯方位量测进行目标运动状态的估计 。

The observability for bearings only target motion analysis is a very important problem. A bearings only system is considered to be observable if, and only if, the target motion parameters can be uniquely determined by noise free bearing measurements. The problem of unobservability for a bearings only target tracking system is discussed in this paper based on the target traveling in the 2 dimensional space at a uniform acceleration. By utilizing Gramme rule and rank of matrix, a proposition that the bearings only locating and tracking system remains unsolvable prior to an observers movement is proved. It is shown that for a certain type of observer's movement the estimation process remains unobservable, even if the target moves at a unitoron acceleration. The study done in this paper is valuable to solving the bearings only target motion analysis.