The Precise Measurement of Magnetic Azimuth

Abstract

This article deals with measuring magnetic azimuthusing inertial sensors. It introduces the steps in this process andobstacles that need to be solved in order to achieve more preciseresults. The magnetic azimuth can be determined using onemagnetometer; however, the precision in such measurement islimited. Therefore, this article also introduces measurement ofrelative azimuth acquired by the gyroscope. The essential part ofprecise measurement is the calibration of the mentioned inertialsensors, which is described in detail. The process of calibration issupported with equations, graphs, and tables. The measurementitself consists of an output from the magnetometer. The relativeazimuth acquired from the gyroscope is then combined using acomplementary digital filter with magnetic azimuth from moreaccurate magnetometer. The final results show the improvementobtained with the presented method. The article also containsinformation on a compact device designed for simple calibrationand measurement with the mentioned sensors.