SUBSURFACE BUOY FOR NON-ACOUSTIC ASW

POTENTIAL FLOW AROUND A MOVING BODY IN A FLUID PRODUCES DISPLACEMENT OF ISOPYCNAL SURFACES. AT THE FREE SURFACE OF THE FLUID, THE DISPLACEMENT IS KNOWN AS THE "BERNOULLI HUMP". TILT OF THE FREE SURFACE CAN BE MEASURED IN ICE-COVERED SEAS WHERE SURFACE WAVES ARE HEAVILY DAMPLED. THE BERNOULLI HUMP PROCEDURES A TILT SIGNAL IN A FREQUENCY BAND WHERE AMBIENT FLUCTUATIONS ARE SMALL. IN THE OPEN OCEAN, SUBMERGING A TILT PLATFORM ATTENUATES MOTION FROM SURFACE WAVES AND MAY PROVIDE A MEANS TO DETECT SUBMARINES PASSIVELY AND NON-ACOUSTICALLY. MEASUREMENTS PROPOSED FOR PHASE I USE A TEST BUOY TO TELL WHETHER A SIMILAR SPECTRAL WINDOW EXISTS AT DEPTH BELOW AN OPEN SEA. THE TEST ALLOWS ASSESSMENT OF THE FEASIBILITY OF USING SUBSURFACE TILTMETER BUOYS TO TRACK SUBMARINES.