Target Localization Using Multi-Static Sonar with Drifting Sonobuoys

Quick and accurate sonobuoy location is becoming more critical in the airborne ASW problem as multi-static search systems and data fusion techniques play more dominant roles. Sonobuoy locations must be determined quickly, and be 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 the assumption that the target will be held in contact for significant periods, will not work. In Phase I, RDA proposes two techniques that can be used to locate sonobuoys by using only acoustic data from the drifting active and passive buoys, without the use of other data. These techniques can be used to locate both source and receiver sonobuoys. One method relies on the received incoherent Direct Blast / coherent ping, and one method uses internal buoy measurements. These techniques can be combined for more comprehensive and smaller positional error measurements. Initial software coding will be in Matlab for rapid development; this also allows extensive simulations for performance measurements. Definition of a transition path to Phase II and commercialization is part of the proposal.