Radio position determining apparatus
Patent 3995273 Issued on November 30, 1976. Estimated Expiration Date: 
November 30, 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.
November 30, 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 References 1562485 3060426 3757340 InventorAssigneeApplicationNo. 572997 filed on 04/30/1975US Classes:342/463Having plural transmitters or receiversExaminersPrimary: Wilbur, Maynard R.Assistant: Berger, Richard E. Attorney, Agent or FirmInternational ClassG01S 5/06 (20060101)AbstractApparatus is provided to determine the relative shift of position of a vehicle carrying a transmitter transmitting at a predetermined frequency. A plurality of receivers are positioned to receive the signal transmitted, and each includes a counter for advancing a count representative of the number of cycles of signal received. A computer receives the counts from the receiver to determine the relative shift of vehicle position. Preferably, a reference transmitter is provided for transmitting a reference signal of predetermined frequency, which, when processed with the signal received from the vehicle, provides a difference or "beat" frequency which provides the basis for cycle counting at a reduced rate. | |
