Grey Correlation Analysis of Magnetic Interference of Aeromagnetic Exploration Flight Platform

Aeromagnetic exploration is an efficient and convenient method for geophysical exploration. In aeromagnetic surveys, how to compensate for the magnetic interference generated by the magnetic components of the aircraft is one of the main problems of aeromagnetic exploration. The initial aeromagnetic compensation model is built around a manned aircraft, and the interference is decomposed into permanent field interference, induced field interference and eddy current field interference. Today, most of the aeromagnetic exploration flight platforms use unmanned aerial vehicle. Compared with manned aircraft, the largest difference is that the UAV fuselage is generally made of non-metallic materials (such as FRP, carbon fiber). The most important source of eddy current magnetic field is the aircraft's metallic structural units. Therefore, the eddy current magnetic field generated by the UAV is relatively small. In order to reduce the complexity of the compensation model, some scholars have proposed that the interference of the eddy current magnetic field is generally not considered in the aeromagnetic compensation of UAV, but such theories lack of quantitative basis. It is necessary to adjust the compensation model.

In this research, we use Gray Correlation Analysis to quantify the magnetic interference of the aeromagnetic exploration flight platform to determine the degree of impact of each interference. The problem of whether the eddy current magnetic interference can be neglected, which can be regarded as the problem that the variable cannot be optimized in the multivariable complex system modeling process. We define the compensation flight system as a gray system, and quantify the dynamic development of each gray influence factor (permanent magnetic field with 3 items, induced magnetic field with 5 items, eddy current magnetic field with 8 items, 16 items in total), with the correlation degree as the quantitative basis. This method has been successfully applied to a rotary-wing UAV flight detection platform. The results show that the eddy current magnetic field has less influence on the UAV detection flight platform, while retaining some quantities in the eddy current magnetic field can improve the compensation accuracy.