AUV-Magnetometer Surveys for Shipwrecks

Archaeologists have sought new methods for identifying and gathering information about shipwreck sites. Historically, researchers have used side scan sonar, human-diver image collection, and boat-towed magnetometer surveys to characterize shipwreck sites. LAIR is working to improve upon these methods by conducting AUV surveys with an in-tow magnetometer. For this project the team will be using the Explorer Overhauser magnetometer integrated with the OceanServer Iver2 (pictured below).

 
 OceanServer Iver2 equipped w/ the Explorer Overhauser magnetometer

OceanServer Iver2 equipped w/ the Explorer Overhauser magnetometer

 

Overhauser magnetometers, used to detect total magnetic field, have proven to be effective at detecting ferromagnetic magnetic materials at the seafloor; thus, identifying metal remnants of shipwrecks. Previous research proves that AUV towed magnetometers lead to accurate surveys of wreckage sites. So, magnetometers like the Marine Magnetics Explorer, easily towed by AUVs, can be used for magnetometer surveys rather than costly boat towed methods. The Explorer is a lightweight sensor (1.2 kg in water) which synchronously logs magnetic field readings to the OceanServer Iver 2, with an absolute accuracy of .1 nT and .001nT resolution This sensor allows for easy deployment and tight survey lines of sites of interest because of the maneuverability of the AUV.

The LAIR team is attempting to make accurate calibration curves for the readings from the sensor to be used in a Bayes Filter for probabilistic determination. Ultimately, the goal is to be able to create 2D probabilistic maps, which give accurate information about shipwreck related anomalies. These maps will be useful in searches for historical wrecks by marine archaeologist.

LAIR is conducting tests at Harvey Mudd College and in Catalina, CA in preparation for live tests in Turks and Caicos.