Bingyang Chen

At present, the research and application of aeromagnetic compensation are almost all based on the Tolles–Lawson (T–L) model. With the development of unmanned aerial vehicles (UAVs), the number of intelligent electronic devices in UAVs is increasing, and the magnetic environment of the platform is becoming more and more complicated. Research shows that the magnetic interference caused by airborne electronic equipment has been very significant, sometimes even reaching 100 nT. The traditional airborne magnetic compensation method based on the T–L model cannot effectively compensate the magnetic interference caused by airborne electronic equipment. Aiming at the problem of magnetic interference of airborne electronic equipment of UAVs, this paper analyzes the origin of magnetic interference of airborne electronic equipment using experiments, and it was found that it is related to the power supply current, and the characteristics of magnetic interference are similar to permanent magnet materials. Based on this feature, we eliminated the magnetic interference caused by the working current of airborne equipment by establishing a linear compensation model based on the current’s source. The experimental data show that the current interference source model proposed in this paper can effectively compensate the magnetic interference generated by airborne electronic equipment and the compensation improvement ratio (IR) is greater than 10.

Eliminating the magnetic interference of the carrier platform is an important technical link and plays a vital role in aeromagnetic survey. The traditional compensation method is based on the Tolles–Lawson (T-L) model and establishes the linear relationship between the aircraft interference magnetic field and the aircraft attitude. The compensation coefficients are solved by designing the calibration flight. At present, almost all aeromagnetic systems use the fluxgate magnetometer fixed to the aircraft to realize the attitude measurement of the flight platform. However, the fluxgate magnetometer has problems, such as non-orthogonal error, zero drift error, and linearity error limited by the production process, and the fluxgate magnetometer is also very susceptible to external magnetic interference as a magnetic sensor. These lead to the aircraft attitude calculated by the fluxgate magnetometer being inaccurate, thus reducing the compensation effect. In this article, we analyze the influence of the fluxgate magnetometer noise on compensation and propose a new conjunctive compensation method based on inertial navigation systems (INS) and fluxgate magnetometer information to improve the compensation effect. The flight experiment data show that the proposed method can significantly improve the quality of aeromagnetic data. Compared with the traditional compensation method only based on fluxgate magnetometer information, the improved ratio is increased by 30–60%, and it is a real-time compensation method. It shows that the proposed method has a remarkable compensation effect for aeromagnetic interference.