载体姿态变化对水下磁场定位精度的影响及监测方法

基于地磁异常反演的水下载体定位方法是为解决水下地磁图不易构建而提出的。将水下地磁异常视为偶极子磁性目标，其磁场大小及梯度由捷联于载体的十单轴磁力计测得，再根据磁场大小及梯度确定载体相对于目标的位置。对目标磁场大小及梯度与载体姿态间的关系，及姿态变化对定位精度的影响进行了理论分析与数值仿真，表明姿态变化对磁场大小的测量几乎没有影响，而对磁场梯度影响大，但载体相对于目标的距离却不随姿态改变而变化。根据目标磁矩与载体姿态角的关系，提出了利用磁矩解算载体姿态变化的新方法，对其进行了理论分析与数值仿真，结果表明，该方法原则上具有较高的解算精度，为监测载体姿态变化提供了一种新途径。

Effect of vehicle attitude variation on underwater magnetic field localization precision and its detection method

Underwater vehicle localization method based on geomagnetic anomaly inversion is proposed for solving the problem that the underwater geomagnetic map is not easy to make. In this method, underwater geomagnetic anomaly can be viewed as a magnetic dipole target. The vehicle position relative to the target is determined by the magnitude of its magnetic field and gradients, which are measured using ten single-axis magnetometers strapped on the vehicle. The relationships between magnetic field magnitude, gradients and vehicle attitude are studied theoretically and simulated numerically, and at the same time its effect on localization precision is also analyzed. These results show that the magnetic field magnitude is not almost influenced by vehicle attitude variation but the effect on its gradients are obvious. However, the distance between underwater vehicle and magnetic target does not almost vary with attitude angles. A novel method to calculate vehicle attitude variation by target magnetic moments is put forward and is studied theoretically and simulated numerically. The results show the calculating precision for the method is higher in principle, which can be used to detect attitude variation of underwater vehicles.