Lloyd L AndersonMontross, VA

4207623, Jun 10, 1980

Feb 8, 1955

4/087001

Lloyd D. Anderson - Takoma Park MD

The United States of America as represented by the Secretary of the Navy - Washington DC

F42B 2204
H04B 1100

367133

1. A system for providing an improved triggering function for firing of a ne from the acoustic signature of a ship passing thereover or in the vicinity thereto comprising means for detecting the envelope of a portion of the audio signature spectrum of the ship, means for deriving a signal corresponding to the logarithm of said detected envelope signal, means responsive to said logarithm signal for providing a signal represntative of the first time derivative thereof, means for subsequently obtaining a signal simulating the second time derivative of said logarithmic signal, means for inverting the phase of said second time derivative signal, means for providing a multiplication of said first and second time derivative signals, and means responsive to said multiplied signals for actuation of a mine detonating circuit.

4189999, Feb 26, 1980

Mar 5, 1956

3/569662

Lloyd D. Anderson - Takoma Park MD

The United States of America as represented by the Secretary of the Navy - Washington DC

F42B 2204

102 18R

1. A submarine mine actuating system responsive to the acoustic pressure nature of a target vessel moving through the water in the vicinity of the system comprising; an array of hydrophones including a first velocity hydrophone having a cosine response pattern and generating an electric signal in response to received underwater acoustic signals originating from said target vessel, and second velocity hydrophone having a response pattern similar to that of said first hydrophone and disposed in orthogonal relation therewith whereby the axes of maximum sensitivity of said hydrophones are mutually perpendicular so that the signals produced by said hydrophones undergo a phase reversal as the target vessel crosses an axis of maximum sensitivity of one of said hydrophones; a pair of transformers each having a primary coil coupled to the output of a respective one of said hydrophones to receive an output signal therefrom, a ring demodulator circuit having a first and a second pair of input terminals each connected across the respective secondaries of said transformers, a center-tap at each secondary winding of said transformers for providing an output signal from said demodulator circuit correlative to the phase relationship of the signals applied across the input terminals of said circuit to thereby indicate a phase reversal of the received acoustic signal as the target vessel crosses the axis of one of said hydrophones of said array.