Three axis magnetometer sensor field alignment and registration

Abstract

An alignment process is applied to each sensor of an array of three axis magnetic sensors to electronically align the three axes of each sensor after the array has been deployed. The alignment process compensates for each sensor not being aligned perfectly with the earth's N-S, E-W and vertical magnetic field components. A field registration process is applied to each sensor of the array that uses a dipole moment detection and localization process and the alignment process combined with a known calibrated dipole source to define the shape of the array. The present invention improves the performance of the array of sensors in detecting magnetic anomalies by digitally compensating for sensor-to-sensor nonalignment and magnetic interferers within interfering range. The alignment process electronically aligns the three axes of each of the sensors to gain maximum performance from the sensor array. Using digital signal processing techniques reduces the physical deployment requirements on the sensors and their relative positions. The alignment process allows the use of three axis vector magnetometers in a distributed field with out having to lay each sensor in perfect alignment with the earth's three magnetic axis. This simplifies the deployment requirements and allows for maximizing the system performance.