Non-GPS Sonobouy Positioning System Navy SBIR FY2008.2 Sol No.: Navy SBIR FY2008.2 Topic No.: N08-151 Topic Title: Non-GPS Sonobouy Positioning System Proposal No.: N082-151-0696 Firm: RDA Inc. P.O. Box 49 Doylestown, Pennsylvania 18901 Contact: Richard Goelz Phone: (215) 340-9514 Web Site: rdainc.com Abstract: Quick and accurate sonobuoy location is becoming more critical in the airborne ASW problem as multi-static active search systems and data fusion techniques play more dominant roles. Sonobuoy locations must be determined automatically and constantly updated in order to estimate target locations as soon as target detection clues are available to the acoustic subsystem. Obsolete methods of buoy location such as "Mark-on-Top", and systems based on assumptions that the target will be held in contact for significant periods will not work. In Phase I, RDA proposes techniques that can be used to automatically locate sonobuoys by extracting information from the sonobuoy signals. Techniques include Angle-of-Arrival (AOA), and Doppler extraction. The AOA approach is applicable to multi-antenna sonobuoy receiving systems, whereas the Doppler extraction approach requires only a single antenna to produce the sonobuoy location. The techniques can also be combined to provide a comprehensive sonobuoy location system. The techniques address the various sonobuoy types and consider the real-world constraints and parameters, and performance is modeled in MATLAB. Preliminary design for a prototype and definition of a transition path to fleet avionics is also part of the Phase I. Benefits: The techniques for sonobuoy location developed under this SBIR will allow ASW aircraft with multiple sonobuoy receiving antenna to automatically determine buoy positions in real time. A subset of the techniques will also allow for buoy location with a single antenna. Where avionics do not include a Software Defined Sonobuoy Receiver (SDSR), the techniques may be implemented in technology that is independent of the existing receiving systems. On platforms where SDSR technology exists, these techniques may provide enhanced capability without additional hardware. The products of this SBIR are applicable to all airborne ASW platforms, including fixed wing (P-3/P-8), Multi-Mission Maritime Aircraft (737-MMA), and rotary wing (SH-60/SR-60). Return