Dual-Vector Aeromagnetic Survey-Based Gradient Imaging and Detection of Target Magnetic Anomaly

As an important target physical field property, magnetic anomaly is considered as a reliable cue to perceive and confirm the presence of magnetic targets. However, concerning its accurate measurement in aerial motion platforms, it is still a challenging task due to the severe interferences caused by the complex sensing environment. Motivated by this, in this article, we propose a dual-vector aeromagnetic survey approach to capture reliable magnetic gradient information for target anomaly detection under dynamic conditions. Specifically, a fluxgate sensor pair is mounted on an unmanned aerial vehicle (UAV) to constitute a vector magnetic gradient measurement system. Meanwhile, a differential correction model is proposed to predict the sensor error parameters and rotation matrix for consistent magnetic gradient calculation. The spatial-temporal magnetic data collected by the dual sensors are collaboratively used to filter out platform interference and background noise, and detect weak target magnetic anomaly signal. Finally, real flight tests are conducted to verify the effectiveness of the proposed approach, and satisfactory gradient imaging and detection results are obtained for typical ferromagnetic targets. Through this, we provide a systematic solution to the gradient detection of target magnetic anomaly under the UAV motion platform, which has wide application prospects in related fields.