Extremely Low Frequency (ELF) for Anti-Submarine Warfare (ASW) Navy SBIR FY2007.2 Sol No.: Navy SBIR FY2007.2 Topic No.: N07-120 Topic Title: Extremely Low Frequency (ELF) for Anti-Submarine Warfare (ASW) Proposal No.: N072-120-0327 Firm: Progeny Systems Corporation 9500 Innovation Drive Manassas, Virginia 20110 Contact: Michael Mullen Phone: (703) 304-2402 Web Site: www.progeny.net Abstract: The US Navy has a requirement for an affordable A-sized independent sonobuoy with an Extremely Low Frequency (ELF) magnetic field sensor suitable for operation in both deep and shallow water regions. The 0.5 to 30 Hz ELF band presents an opportunity to detect galvanic current from submarines, especially those which are poorly maintained. ELF sensors have been used in fixed mounted applications, however free floating sonobuoy configurations pose complications due to motion induced noise, control of sensor orientation, and miniaturization. To address the technical challenge of motion induced noise we propose to develop our ELF sensor concept teamed with UnderSea Sensor Systems, Inc. which senses horizontal flow and repositions the drogue and ELF sensing element to a stagnation point. Whole field magnetometers will eliminate the need for precise orientation of the sensors. Additionally we will use of multiple ELF sensing elements to correlate and discriminate far-field geomagnetic noise. Benefits: This effort will lead to the development of an inexpensive A-size sonobuoy capable of independently detecting and processing Extremely Low Frequency (ELF) magnetic field signals emitted by submarines in both deep and shallow water. Dual-use commercial applications include the use in oil and mineral industries for exploration and magnetic characterization of the fields. Return