Spatially Integrating Optical Magnetometer (S-IOM)

The U.S. Navy is currently using a Closed Loop Degaussing Systems (CLDG) on their Virginia-class and their future planned Columbia-class submarines to reduce their overall magnetic signature to make them less vulnerable to detection. The current CLDG systems on the Virginia-class submarines utilize multiple discrete tri-axial (i.e. three-axes) magnetic field (B-field) sensors that measure the localized B-field surrounding the discrete sensors, which are permanently installed in the hull of the ship. The current B-field sensor of choice is a 3-axes Flux Gate Magnetometer. Unfortunately; the system performance of these discrete FGM’s is adversely affected by local anomalies from a multitude of nearby magnetic sources/materials such as: electronic equipment, rotating machinery, structural welds, support beams, etc. The magnetic sensors required for CLDG have many stringent requirements including: high physical and electronic stability, low sensor noise, and high measurement accuracy over a range of temperatures and B-fields that are encountered during shipboard engineering spaces. The overall goal of the proposed Phase II effort is to synergistically combine two types of magnetic measurement systems that are not adversely affected by these local magnetic anomalies so that the correct input can be provided to the CLDG system and hence make the submarine less vulnerable to detection from its magnetic signature. The highly detailed and successful Phase I experimental investigation compared two separate integrated B-field measurement techniques: a) a Flux Gate Magnetometer (FGM) using discrete 3-axes FGM sensors and b) a true continuous Spatially Integrating Magnetometer (SIM). The primary Technical Objectives of the Phase II Base are to improve the B-field measurement sensitivity of the continuous SIM. To accomplish this task, a new digital based SIM version with superior SWaP, will replace the older analog SIM unit. Once the new digital SIM has been fabricated, e2P will synergistically combine the continuous SIM with the discrete FGM sensors using e2P’s proprietary Calibration Techniques. The combined approach will provide an unequaled SIM with superior performance enhancement over the entire dynamic range of operation compared to any competitor. This will result in the desired outcome of providing the correct input to the CLDG system when localized magnetic perturbations are present, thereby reducing the magnetic signature of the ship/submarine.