基于归一化磁源强度的磁目标实时定位方法

Real⁃Time Magnetic Target Localization Method Based on Normalized Source Strength

标量三角剖分与测距(STAR)方法利用磁梯度收缩特性实现运动状态下对单个磁偶极子目标的实时定位,且对运动平台的姿态不敏感。然而,磁梯度收缩量(C_(T))引入的非球面误差会限制其定位精度。针对该问题,提出了一种新的磁偶极子目标线性定位方法,利用归一化磁源强度(NSS)代替C_(T),消除了非球面误差的影响。为了分析该方法对不同方位磁目标的定位性能,建立了全向仿真分析模型。仿真结果表明,该方法的实时性与STAR方法相当,在标准差为10 nT的高斯白噪声影响下与STAR方法的最大定位误差分别为0.18 m与1.5 m。现场实验结果表明,当探测距离为1.284 m时,该方法在纬线轨迹上的平均定位误差仅为0.094 m,比传统STAR方法低56.7%;在经线轨迹上的平均定位误差为0.097 m,比传统STAR方法低30.7%。

The scalar triangulation and ranging(STAR)method can realize the real-time localization of a single magnetic dipole target in the moving state and is not sensitive to the attitude of the moving plat-form,which is based on the characteristics of magnetic gradient contraction.However,aspherical error introduced by magnetic gradient contraction(C_(T))limit the localization accuracy.To solve this problem,a new linear localization method for magnetic dipole target is proposed in this paper,which uses normalized source strength(NSS)instead of C_(T) to eliminate the influence of aspherical errors.In order to analyze the localization performance of the proposed method on magnetic targets with different orientations,an omnidi-rectional simulation model with a detection range of 10m was established.The simulation results show that the real-time performance of the proposed method is as good as that of the STAR method,and the maximum localization errors of the proposed method and the STAR method are 0.18 m and 1.5 m respec-tively under the influence of noise.Field experiment results show that when the detection distance is 1.284 m,the average localization error of the proposed method on the latitude trajectory is only 0.094 m,which is 56.7%lower than that of the traditional STAR method.The average localization error on the longitude trajectory is 0.097 m,which is 30.7%lower than the traditional STAR method.