Updated diver navigation device
Patent 3944967 Issued on March 16, 1976. Estimated Expiration Date: 
March 16, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 16, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References3475721 InventorsApplicationNo. 535542 filed on 12/23/1974US Classes:367/117, PLURAL TRANSMITTERS TO RECEIVER OR TRANSMITTER TO PLURAL RECEIVERS128/201.27, Diving or swimming apparatus367/125, Phase comparison and/or correlation367/137, TRANSMITTER SYSTEMS367/910PORTABLE SONAR DEVICESExaminersPrimary: Farley, Richard A.Attorney, Agent or FirmAbstractIn a diver's navigation system employing a receiver having three equal, alarly disposed hydrophone locations, a digital signal processing circuit is employed which receives frequency shift keyed digital data from remote beacons. Circuitry is provided to process this data to derive a bearing indication to the beacon. | |
