Device for measuring the velocity of a body in an undersea environment
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorJohn R. Thompson
Life of this patent
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Abstract
A hollow, projectile-shaped body containing an acoustical transducer is rased into the sea such that the body descends in free fall until it strikes and penetrates the sea floor, coming to a rest therein. Acoustic signals emanating from the acoustic transducer are processed utilizing the doppler effect to generate a direct current analog signal which is the function of the velocity of the body from a time immediately preceding the body striking the sea floor surface until the body comes to rest in the sea floor, thereby obtaining an indication of the physical characteristics of the sea floor.
Claims2
An undersea apparatus for generating an acoustical a-c signal whose frequency is a function of said apparatus velocity in an undersea environment comprising:
- a. a hollow projectile shaped body having a nose thereon, said body containing an acoustic transducer;
- b. an impeller rigidly affixed to a shaft, said impeller being disposed outside said body, said shaft extending from inside said body through said body nose to said impeller, said shaft rotating with respect to said body, said impeller having a speed of rotation functionally related to the speed of said body in the water;
- c. means connected to said shaft for generating a direct-current signal whose amplitude is functionally related to the speed of rotation of said impeller, said means being located inside said body;
- d. a voltage-controlled oscillator connected to receive said direct-current signal and generate an a-c signal whose frequency is functionally related to the amplitude of said direct-current signal, said a-c signal driving said acoustic transducer, said oscillator located inside said body.
Dependencies are inferred from the claim text.