Magnetic survey and autonomous target reacquisition with a scalar magnetometer on a small AUV

A scalar magnetometer payload has been developed and integrated into a two-man portable autonomous underwater vehicle (AUV) for geophysical and archeological surveys. The compact system collects data from a Geometrics microfabricated atomic magnetometer, a total-field atomic magnetometer. Data from the sensor is both stored for post-processing and made available to an onboard autonomy engine for real-time sense and react behaviors. This system has been characterized both in controlled laboratory conditions and at sea to determine its performance limits. Methodologies for processing the magnetometer data to correct for interference and error introduced by the AUV platform were developed to improve sensing performance. When conducting seabed surveys, detection, and characterization of targets of interest are performed in real-time aboard the AUV. This system is used to drive both single- and multiple-vehicle autonomous target reacquisition behaviors. The combination of on-board target detection and autonomous reacquire capability is found to increase the effective survey coverage rate of the AUV-based magnetic sensing system.