Atmospheric Noise Cancellation for Low Frequency (LF) and Very Low Frequency (VLF) Navy SBIR FY2006.3 Sol No.: Navy SBIR FY2006.3 Topic No.: N06-169 Topic Title: Atmospheric Noise Cancellation for Low Frequency (LF) and Very Low Frequency (VLF) Proposal No.: N063-169-0350 Firm: GIRD Systems, Inc. 310 Terrace Ave. Cincinnati, Ohio 45220 Contact: Bruce Hart Phone: (513) 281-2900 Web Site: www.girdsystems.com Abstract: Very Low Frequency (VLF) and Low Frequency (LF) reception suffers from interference of atmospheric noise caused by lightning, which occurs year round. In this proposal we investigate innovative mitigation methods that have the potential of suppressing atmospheric noise in LF/VLF communications. Performance objective is to improve routine VLF and LF reception in natural atmospheric noise conditions that will permit greater communications range and to reduce the cost of providing electrical power to the Navy fixed VLF and LF transmitters. Extensive computer simulations will be performed to evaluate the developed methods, and a final recommendation will be provided at the end of Phase I. Benefits: If successful, the potential benefits of this program would be greater LF/VLF communications range and reduction of the cost of providing electrical power to the Navy fixed VLF and LF transmitters. It is estimated that a 3 dB improvement in the signal to noise performance of VLF and LF radios would allow an approximate 1 MW power reduction at each Fixed Submarine Broadcast System (FSBS) transmit site providing an approximate savings of $80/hour. As each of the six transmitters operates 24 hours each day for 312 days per year, the resulting annual cost savings would be $ 599,040.00 per station, and an annual savings of $3.6M for all six stations. Additionally, airborne operational benefits may also be realized. Other commercial applications include radios operating in the commercial AM broadcast band and High Frequency (short wave) bands, as well as communications through power lines. Return