Compact Underwater Electromagnetic Sensor with Internal Data Logging

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Microelectronics OBJECTIVE: Develop an Underwater Electromagnetic (UEM) sensor package that includes magnetic and electric field sensing, and internal data logging. The sensors need to be sensitive to small field variations, stable in underwater environments, and packaged in a compact design with self-contained data logging. DESCRIPTION: Current UEM measurement systems on the market are typically bulky and are not designed to support simple transportation methods and ad-hoc stand-alone deployments. A majority of these systems are limited to specific sensors and the electronics supporting the measurement components have not been optimized for smaller form factors. Over the last decade, sensors and electronic improvements to power consumption and form factor could enable smaller sensor packages and increased endurance. The end product of this SBIR topic will be a stand-alone compact UEM sensor that can be easily deployed and recovered in an ocean environment that can measure magnetic and electric fields. When deployed, the UEM sensor will land and operate from the seafloor. The UEM sensor is expected to be able to be deployed and collect data for up to 7 days. The magnetic field sensing should be capable of collecting magnetic field in all three orthogonal vector components. The electric field sensing capability should also be capable of collecting electric field in all three orthogonal vectors components. The compact UEM sensor should also consist of a pressure sensor to enable post-processing of system depth during the data collection windows. The UEM sensor should be programmable to enable delayed operations and allow for targeted data collection windows. The UEM sensor should be packable into a 6.75 diameter cylinder and shall not exceed 80 inches in length. Upon deployment, the system can expand as required to support data collection operations and recovery. The awardee will be expected to fabricate 3-5 prototype compact UEM sensors to test in the lab and on land to ensure all the capabilities are integrated, power consumption is verified, and data storage is adequate for the length of deployment. Additionally, the electric field and magnetic field measurement capabilities will be tested to ensure noise levels are satisfactory. After lab testing is completed and noise levels are demonstrated, if satisfactory with U.S. Navy expectations, the next effort will be to deploy and test the compact UEM sensor at the South Florida Ocean Measurement Facility (SFOMF) in Dania Beach, FL to demonstrate the total system performance in an operational environment to achieve TRL 7. The sensor recoverability will also be demonstrated. PHASE I: Define and develop a concept for a compact underwater UEM sensor with internal data logging that can meet the performance and the SWaP constraints listed in the Description. Perform modeling and simulation to provide initial assessment of concept performance. The Phase I Option, if exercised, includes the initial layout and capabilities description to build the unit in Phase II. PHASE II: Develop and deliver 3-5 prototypes based on Phase I work for demonstration and validation. Three to five prototypes should be delivered during the Phase II for lab and field testing as identified in the Description. Additional testing as identified in the Description will be performed to demonstrate the total system performance in an operational environment. Sensor recoverability will also be demonstrated. PHASE III DUAL USE APPLICATIONS: Assist the Navy in transitioning the technology to Navy use. The Navy would use these sensors as an alternative to collect UEM signature measurements of ships and submarines that don't have operational measurement arrays available. The compact design and portability allow for low-cost, feasible shipping methods that could be rapidly deployed in various locations. The sensors could also benefit civilian uses including geologic surveys of the ocean floor, ocean wave dynamics research, and other related areas of interest. Reducing sensor and acquisition noise, optimizing sensor battery life and data storage, and other issues would decrease maintenance costs of existing systems, providing additional feasibility for a variety of applications. REFERENCES: 1. Spichak, Viacheslav V. Advances in electromagnetic techniques for exploration, prospecting, and monitoring of hydrocarbon deposits. First Break, Volume 36, Issue 10, Oct 2018, p.75-81. https://www.earthdoc.org/content/journals/10.3997/1365-2397.n0129 2. Slater, Michael. Oregon Wave Energy Trust. Electromagnetic Field Study: Summary of commercial electromagnetic field sensors for the marine environment. Oregon State University, ScholardArchive@OSU, July 8, 2017. https://ir.library.oregonstate.edu/concern/technical_reports/db78tc64w 3. Electromagnetic Field Effects on Marine Life. U.S. Offshore Wind Synthesis of Environmental Effects Research (SEER), December 2022. http://www.crmc.ri.gov/meetings/2022_1213semipacket/SEER_EMF_MarineLife.pdf KEYWORDS: Compact Acquisition Systems; Underwater Electromagnetic Signatures; Magnetometers; Electropotential; Electric Field; Magnetic Field