Application of an Improved Calibration Flight Scheme in Aeromagnetic Interference Compensation.

In aeromagnetic measurement, accurate compensation for the interference magnetic field generated by the aircraft platform due to the aircraft maneuvering in the Earth's magnetic field is an important prerequisite for the accurate identification of the magnetic anomaly signal of the detection target. The flaws of the traditional calibration flight scheme in aeromagnetic interference compensation are firstly analyzed, and then an improved scheme is proposed, featuring smaller calibration flight areas, more simplified maneuvers, shorter flight route and less influence from the magnetometer's direction and extreme weather. The improved scheme can enhance the robustness of the aeromagnetic interference compensation matrix and improve the compensation efficiency, and thus both the solved magnetic compensation coefficients and compensation effects are significantly improved. The experimental results of the aeromagnetic interference compensation in an area of Inner Mongolia of China show that the average accuracy of the repeated survey lines, which are compensated by the improved scheme, can be increased by 5 and 3 nT, respectively, compared with the uncompensated results and the results compensated by the traditional scheme. Therefore, the effectiveness and superiority of the improved calibration flight scheme is fully proved. Plain Language Summary: Aeromagnetic measurement technology is the most economical and effective technical means to obtain high‐precision and high‐resolution geomagnetic information. Because the aircraft used in aeromagnetic measurement is composed of ferromagnetic materials, it will produce an interference magnetic field when maneuvering in the Earth's magnetic field. In order to obtain pure geomagnetic field measurement data, it is necessary to compensate the interference magnetic field. The traditional calibration flight scheme is widely used in the aeromagnetic interference compensation, and has played an important role in the existing aeromagnetic measurement. However, with the continuous improvement of the measurement accuracy of airborne magnetometers, there are higher requirements for calibration, and some defects of the traditional calibration flight scheme are found in practice. Hence, an improved calibration flight scheme is proposed in this paper, which features smaller calibration area, shorter flight route, simplified maneuvers and less influence from the direction of the magnetometer. The experimental results show that the modified scheme can improve the average accuracy of repeated survey lines by 3 nT compared with the traditional one. Therefore, the improved scheme can be directly applied in the aeromagnetic interference compensation of scalar, vector and gradient magnetic measurement of manned and unmanned aerial vehicle (UAV). Key Points: An improved calibration flight scheme is proposed in the aeromagnetic interference compensationEffectiveness and superiority of the improved calibration flight scheme are validated by actual flight dataCompared with the traditional scheme, the improved one can increase the average accuracy of repeated lines by 3 nT [ABSTRACT FROM AUTHOR]