The use of magnetic field measurements for airborne detection of submerged submarines has a history that goes back to at least World War II. The technology makes use of the fact that a submarine is in effect a large magnet, and its magnetic field causes localized changes (“anomalies”) in the earth’s magnetic field, which can be detected by field measuring instruments – magnetometers.
Laser Magnetometer for UAVs and Helicopters
Polatomic has developed a laser-pumped scalar magnetometer for use in Anti-Submarine Warfare (ASW) applications by the Naval Air Systems Command (NAVAIR). This system, known as the Multi-Mode Magnetic Detection System (3MDS), is planned for deployment in Unmanned Aerial Vehicles (UAVs) and ASW helicopters. The picture below illustrates the concept. The 3MDS is “multi-mode” in that it operates in Extremely Low Frequency (ELF) mode as well as conventional MAD mode. The laser magnetometer system designated the AN/ASQ-233 shown below is suited for new patrol aircraft such as the Navy MMA program and as a replacement for existing magnetic anomaly detection (MAD) systems in existing ASW aircraft.
AN/ASQ-233A Digital Magnetic Anomaly Detecting Set
AN/ASQ-233A Digital Magnetic Anomaly Detection (DMAD) Set is an
advanced laser-pumped Helium magnetometer system designed to detect
sub-surface magnetic anomalies caused by submarines. The AN/ASQ-233A is
suitable for fixed wing or helo applications.
The DMAD system consists of two Weapon Replaceable Assemblies (WRAs), fourteen less than the 16 AN/ASQ-81 associated WRAs.:
– Houses multi-axial Scalar and Gradient Magnetometers with Electronics
and Laser Subassemblies. The Sensor also provides data for compensation
of magnetic signals caused by aircraft maneuvers and environmental
Control/Display – Controls the DMAD Modes and
sub-functions. It receives raw and compensated Magnetometer data and
formats it for display, storage, and post-mission data extraction. This
unit processes, displays multiple band-pass signals, and analyzes their
characteristics to identify and declare anomaly detections.
High Sensitivity Laser Pumped Helium Sensor
Proven High Reliability
No Mechanical Servos
Integrated Vector Magnetometer
Digital Aircraft Motion & Environmental Magnetic Compensation
Automatic Detection With Range & Confidence Estimate
Detection Tone to Operator
Digital Single, Multi-Band, Multi-scale Display
ELF Processing and Display
Integrated Digital Data Recording, Playback, and Download
Magnetometer Variants DMAD variants include compact form factors suitable for installation into Helicopters, UAVs, UUVs for sea-buried mine detection, and space craft for Earth and planetary magnetic field studies (Cassini Saturn Mission), and underwater sensor arrays.