Precise positioning is a prerequisite for airborne high-quality magnetic data surveying. Modern airborne magnetic surveying platforms are usually composed of two parts: an aerial vehicle and a suspended magnetometer assembly. This configuration poses a challenge for georeferencing of data since the sensitivity of the magnetic sensors prohibits the placement of electronic positioning sensors directly on the assembly. This work focuses on the development of a positioning approach using computer vision and sensor fusion, which provides a globally referenced position, as well as preserving the electromagnetic isolation for the magnetic sensors. For the sake of magnetic isolation, the proposed approach estimates the position by fusing the relative position between the UAV and the magnetic sensor as well as the global position of the UAV itself. Compared with other solutions, the proposed solutions present two main advantages: (1) It is passive and provides excellent magnetic isolation to the sensitive magnetic sensor; (2) it can continue to provide the position of the magnetometer even if the sensor is in certain environments where direct positioning using global navigation satellite system or visual odometry would fail. We present the complete solution, including the temporal/spatial alignment of the GNSS/INS system and camera, front-end vision-based detection and tracking, and back-end position estimation and optimization. For performance evaluation, we use a commercial GNSS/INS system on the assembly as a reference and then compare the result of the proposed method with respect to the reference. The results from several real flight tests show that the vertical and horizontal accuracy of the proposed method is at centimeter level and decimeter level, respectively, which comes close to the performance of the reference system.

精确定位是机载高质量磁数据测量的前提。现代的机载磁测量平台通常由两部分组成：飞行器和悬挂式磁力计组件。由于磁传感器的灵敏度禁止将电子定位传感器直接放置在组件上，因此这种配置对数据进行地理配准提出了挑战。这项工作集中于使用计算机视觉和传感器融合的定位方法的开发，该方法提供了全球参考的位置，并保留了磁传感器的电磁隔离。为了磁隔离，所提出的方法通过融合无人机和磁传感器之间的相对位置以及无人机本身的全局位置来估计位置。与其他解决方案相比，提出的解决方案具有两个主要优点：（1）它是无源的，并且为灵敏的磁传感器提供了出色的磁隔离；（2）即使传感器处于使用全球导航卫星系统或视觉测距法无法直接定位的某些环境中，它也可以继续提供磁力计的位置。我们提出了完整的解决方案，包括GNSS / INS系统和相机的时间/空间对齐，基于前端视觉的检测和跟踪以及后端位置估计和优化。为了进行性能评估，我们在组件上使用了商用GNSS / INS系统作为参考，然后相对于参考比较了所提出方法的结果。