Research/Patents/US 5025425
US 5025425

SONIC DETECTION AND TRACKING SYSTEM

Assignee

Filed

Apr 30, 1970

Granted

Jun 18, 1991

Location

HATBORO PA US

Abstract

Two submerged rotatable sets of transmitting and receiving transducers areongitudinally spaced along the side of a river to establish intersecting lateral sonar beams obliquely oriented at opposing 45° angles relative to the primary river current. Each beam can be slewed in opposite directions through 45° to parallel orientation with the current. The outputs of the transducer arrays are passed to respective doppler sonar detection units which produce alarm output signals when the normalized doppler frequency shift within at least one of a plurality of narrow frequency bands in each unit exceeds a predetermined level. The transmitting frequency of each array is varied with rotation of the array. If only one beam detects a target, a control circuit causes the other beam to slew until it acquires the target. With detection by both beams, the position of the target can be computed from the bearing angles of the arrays.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Jul 22, 1982

Rescinded

Nov 8, 1990

Duration

8 years, 3 months

Inventor

  • 1HENRY SUTER

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records