Magnetic Compensation of Magnetic Noises Related to Aircraft's Maneuvers in Airborne Survey

Abstract

For a variety of applications, magnetic data is collected from airborne platforms. Normally, this data is collected with sensors that measure the total field or amplitude of the magnetic vector data. New generations of optically pumped sensors are extremely sensitive with their sensitivity quoted often in picoteslas. At present, some new instrumentation is also attempting to measure high accuracy vector data. Despite the accuracy of modern sensors and data acquisition systems, the noise of the flying platform is still one of the limiting factors in obtaining highly accurate data.The aircraft or helicopter itself emanates magnetic signals. These signals are due to a number of factors including induced fields due to magnetically susceptible materials and permanent magnetic materials on the platforms as well as both induced electromagnetic signals and electromagnetic signals generated either by electrical systems or moving parts such as rotors.This subject of this paper are problems and techniques related to removing the effects of the moving platform as well as attempts to study the subject with the use of simulated data.

An Adaptive Filter for Aeromagnetic Compensation Based on Wavelet Multiresolution Analysis

“…However, considering only the frequency characteristics of the aircraft maneuvers and filtering the data with a frequencydomain filter cannot always guarantee an expected result. In fact, the Gaussian filter applied in time-domain turns out to be more appropriate [16]- [18] than the frequency-domain filter, which is also confirmed by our simulation results in Section IV. This may be caused by the shortcomings of the discretetime Fourier transform.…”

“…The performance of an actual compensation system depends not only on the system itself but also on other external factors, e.g., the quality of the installation on the aircraft [20], which can be addressed in a separate way. Therefore, to avoid these effects, numerical simulation data sets are used to explore the decision function (18) and evaluate the performance of the adaptive filter. In the numerical simulation, the calibration flights are simulated through FlightGear [30] to provide the aircraft's location and attitude data, which will be put into the World Magnetic Model 2015 [31] to generate the geomagnetic field information.…”

“…For decades, much work on different aspects (such as modeling and analysis [1]- [4], parameter estimation [5]- [10], system implementation [11]- [18], etc.) has been carried out in the field of aeromagnetic compensation, and commercial systems are available from a number of companies [19].…”

“…To address this problem, many scholars have presented different solutions to estimate the coefficients based on the advanced regression theory, e.g., [22]- [24]. Meanwhile, considering that a bandpass or high-pass filter should be applied to the system of linear equations to extract the signal component related only to the aircraft maneuvers, Jia, Lo, and Groom pointed out that the issue of multicolinearity could be resolved by selecting an appropriate filter and recommended a Gaussian filter (see [16]- [18]). Unfortunately, however, the selection of this filter is not justified in detail.…”

A method for aircraft magnetic interference compensation based on small signal model and LMS algorithm

“…During the survey, aircraft magnetic field is the main interference to the magnetic sensor. [1][2][3][4][5] Usually, there are ferromagnet in the aircraft which produce magnetic field. 6 And Tang et al 7 points out that the plasma generated by vaporization ionization of the projectile could produce magnetic fields.…”