ELECTROMAGNETIC DETECTION OF BURIED MINES USING A SUPERCONDUCTIVE MAGENETIC GRADIOMETER

MINES BURIED IN THE SEA BOTTOM ARE OFTEN IMPOSSIBLE TO DETECT ACOUSTICALLY. ELECTROMAGNETIC ENERGY PROVIDES AN ALTERNATIVE MEANS OF DETECTION. AN ACTIVE SYSTEM FORMED BY A SOURCE CURRENT ENCIRCLING A SUPERCONDUCTIVE MAGNETIC GRADIOMETER HOLDS THE PROMISE OF PROVIDING AN UNDERWATER-TOWED SYSTEM FOR DETECTING BURIED MINES ELECTROMAGNETICALLY. THE SOURCE CAN OPERATE AT FREQUENCIES OF A FEW TENS OF HENTZ, WHICH ARE LOW ENOUGH TO PENETRATE SEAWATER EFFECTIVELY BUT HIGH ENOUGH TO EXCITE SENSIBLE EDDY CURRENTS IN METALLIC TARGETS. THEY ALSO ARE HIGHER THAN FREQUENCIES OF NOISE ARISING FROM SEAWATER MOTIONS AND TOWED BODY DSCILLATIONS. FIRST ESTIMATES SHOW THAT USEFUL DETECTION RANGES, 15 M, CAN BE ATTAINED FOR PRACTICAL SOURCE MOMENTS, 104A M2. WE PROPOSE FIELD MEASUREMENTS TO EVALUATE THE FEASIBILITY OF OPERATING A SUPERCONDUCTIVE GRADIOMETER WITHIN AN ENCIRCLING CURRENT AND TO DETERMINE THE EXPECTED IDEAL PERFOMANCE OF THE SYSTEM.