The Self-Compensating Magnetometer (SCM) System – Test Results from a Remus 600 AUV Survey in Yellowstone Lake
Panel Session: Unmanned Vehicles and Vessels - Innovations in Autonomy
Location: Conference Room 26B
Date and Time: Wednesday Feb 15th from 16:00 - 17:30
In 2016, Ocean Floor Geophysics (OFG) released a new Self-Compensating Magnetometer (SCM) system to the subsea industry. This magnetometer was designed specifically for use in autonomous underwater vehicles (AUVs) and some remotely-operated underwater vehicles (ROVs). Using data collected during a calibration maneuver, correction coefficients are calculated for the magnetization of the AUV itself, its attitude in the Earth’s magnetic field, and for variable electro-magnetic effects related to the power drawn by the vehicle’s propulsion and maneuvering system. This compensation algorithm eliminates the need to tow the magnetometer or degauss the vehicle to collect useful magnetic data.
Collecting data with a magnetometer mounted inside or on an underwater vehicle enables the production of much higher resolution magnetic maps than those produced using a surface vessel. Using the SCM, magnetic data can be collected concurrently with high resolution multibeam, side scan, and/or sub-bottom data enabling the interpretation of geology on a local scale instead of a regional one.
As part of product testing, OFG has deployed the SCM on vehicles by various AUV manufacturers. We discuss here the data from a magnetometer deployed on Remus 600 AUV doing a multibeam mapping project in Yellowstone Lake. Magnetic data was collected over four dives and compensation was applied to the raw data using the SCM algorithm. Maps were generated and compared with historical magnetic data collected using airborne techniques. The comparison shows that the data collected using the OFG SCM is consistent with the airborne results but provides significantly more detail, revealing features that were not visible in the airborne data. These local features can provide useful and detailed geological data that compliments the precision bathymetry collected by the AUV.