Compensation Technique Of Magnetic Disturbance For Airborne Geomagnetic Survey

Geomagnetic field is the basic field of earth’s, the Earth has a magnetic field at any point near Earth space, the strength and direction will be different with different latitude and longitude and height, contains a wealth of information. In addition, the geomagnetic field has advantages of passive, no radiation, all-time, fine accuracy, whole area and low power consumption. The magnetic field has been widely used in the magnetic compass, GPS and geological disaster forecast with the theory of geomagnetic continuous improvement and sensors, microprocessors and application algorithms matures.Aerial survey is an effective means to obtain geomagnetic field data, in order to achieve high-precision measurements, we must overcome the magnetic disruption of airborne environment. This article uses the DC motor model aircraft to study the magnetic disturbance compensation as the high cost and difficult operating issues of the actual existence aerial platforms, the sources of interference include the inherent error of the sensor, ferromagnetic interference generated by Carrier, the motor’s dynamic magnetic bias, and the motor’s dynamic high-frequency alternating magnetic interference. Typically, magnetic values changes very weakin within a certain area, but due to the interference, in airborne conditions the measurement signal fluctuations greatly Therefore, we must compensate the magnetic interference effectively.This paper carried out a detailed analysis of the background interference for airborne geomagnetic survey, proposed compensation package for different interference.Using the geomagnetic survey data under multiple pose conditions, solver environmental magnetic interference parameters by nine parameters model, Achieve comprehensive Interference compensation of inherent sensor error and ferromagnetic; Raised the equivalent current compensation method for the elimination of magnetic bias generated by motor operation; then introduce the digital Kalman filter, get the appropriate filter parameters through Matlab simulation, eliminating the high frequency dynamic magnetic interference.Written procedures for ARM7-based embedded, based on the methods and models mentioned above, optimization hardware and software by demand for the work environment. Designed interface for compensation algorithm, easy to verify and change.Verify the compensation effect by experimental using self-designed embedded magnetic measuring device, It shows that the method can obtain real time and accurate geomagnetic values, reduce the motor’s magnetic field interference under simulated test conditions.