Components for a Deep Drifting Sonobuoy

A unique undersea acoustic phenomenon called Reliable Acoustic Path (RAP) offers an opportunity for a paradigm shift in air-ASW CONOPS. In areas where the ocean reaches sufficient depths, the density of the water increases to the point where the speed of sound exceeds that at the surface. An acoustic receiver placed below this critical depth benefits from greatly improved signal to noise ratio. The Next Generation Airborne Passive System FNC, or NGAPS, was born out of this research. NGAPS will provide the fleet with persistent, broad area surveillance by positioning passive receive arrays at RAP depths. A single P-8 aircraft is capable of deploying an extremely large area field comprised of 25-100 receivers. Recent studies funded by PMA-264 suggest that free drifting RAP-depth buoys can be designed to limit drift speeds so that a field can maintain integrity for weeks at a time. The opportunity, then, is to develop a long life (30-90 days) RAP sonobuoy in an A-size form factor capable of performing in-buoy processing and sending OTH contact reports. This capability will dramatically reduce the cost of conducting long term anti-access, area-denial ASW in deep water, while freeing valuable P-8 flight hours for other missions.