## 1 Introduction  
Aeromagnetic survey is a method to detect weak magnetic anomaly signals of underground or underwater targets by using an aircraft equipped with high-precision magnetometer to scan the doubtful areas [1]. Comparing with ground magnetic survey, it has the advantages of high detection efficiency and large operation area [2], so it is widely used in geophysical exploration [3], mineral exploration [4], and underwater anti-submarine detection [5]. Helicopters and fixed-wing aircrafts are the most commonly used carrier platforms in aeromagnetic survey. In the process of aeromagnetic measurement, the ferromagnetic materials and conductive materials of the aircraft platform can produce interference magnetic fields when the platform is maneuvering [6]. It affects the accuracy of the magnetometer and limits its detection performance. Therefore, eliminating the magnetic interference of the aircraft platform plays a vital role in aeromagnetic measurement and is an important technical link of aeromagnetic surveying. In 1950, [PERSON] and [PERSON] proposed that the aircraft's interference field can be divided into three parts: (1) remanent magnetic field;(2) induced magnetic field; and (3) eddy current field [7; 8; 9], and established a linear compensation model with 18 coefficients related to magnetic interference and attitude of aircraft. The accuracy and stability of model coefficients determine the compensation effect. The compensation coefficient was calculated by calibration flight. In order to improve the accuracy of coefficient calculation, it is necessary to obtain the attitude information of the aircraft as accurately as possible. The sensor that can directly reflect the change in aircraft attitude is INS, but it is not clear how to substitute the INS information into a T-L model and the INS is not precise enough. The current mainstream aeromagnetic compensation system mainly consists of an optical pump magnetometer (OPM) and fluxgate magnetometer. An OPM is used to measure the field with high precision. Fluxgate magnetometers measure magnetic field vectors. The fluxgate magnetometer is fixed on the aircraft platform, and the change in aircraft attitude can be obtained directly through the measured values of the three axes of the fluxgate magnetometer and applied to the T-L model. However, due to the limitation of production technology and processing level, the fluxgate magnetometer has some problems, such as non-orthogonal error [10], zero drift error [11], and temperature drift [12; 13; 14], and as a magnetic sensor, a fluxgate magnetometer is also easily affected by external magnetic interference. As a result, the change in fluxgate magnetic field value caused by aircraft maneuvering may be submerged, thus making the compensation coefficient obtained by calibrated flight inaccurate, thus reducing the compensation effect. In terms of fluxgate error correction, [PERSON] proposed other sensors, such as an inertial measurement unit (IMU) or gyro, also used to calibrate magnetic sensors [15]. In [16], the author proposed a fluxgate magnetometer calibration method by using the least square method and particle swarm optimization algorithm. [PERSON] introduced a hybrid optimizing algorithm to compensate the dynamic error of fluxgate magnetometers [17]. However, due to complex working conditions and many interference factors, equipment errors are often unpredictable, and the influence mechanism of fluxgate interference on compensation is not clear. This makes it difficult to improve the compensation effect by adjusting the fluxgate magnetometer. In order to reduce the influence of fluxgate error on aeromagnetic compensation and improve the compensation accuracy, this paper analyzes the influence of the fluxgate magnetometer noise on compensation and the simulation experiment is carried out. The simulation results show that the larger the noise of the fluxgate magnetometer, the worse the compensation results.