ISO-PHASE NAVIGATION SYSTEM

• US 3,803,610 A
• Filed: 05/26/1971
• Issued: 04/09/1974
• Est. Priority Date: 08/01/1969
• Status: Expired due to Term

• Current Assignee: Teledyne Industries Incorporated (Teledyne Technologies Incorporated)
• Original Assignee: Charles E. Hastings, William A. Rounion
• Inventors: Hastings, Charles E., Rounion, William A.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Buczinski, S. C.
• Application Number:
  US05/147,266
• Time in Patent Office: 1,049 Days
• Field of Search: 343/15R,15LS,15H,114.5
• US Class Current: 342/396
• CPC Class Codes: G01S 1/308 particularly adapted to Omega systems

Abstract

An Omega navigation system is disclosed which includes a relay station at a fixed location. The relay station includes a receiver for receiving the signals being braodcast by the Omega transmitting stations and an arrangement for determining the phases of the signals thus received. The relay station also includes a transmitter for broadcasting a signal indicative of the phase of the signals as received at the relay station. The mobile station in the system is provided with a first receiver for receiving the signals broadcast by the Omega transmitting stations, in a conventional manner, and a second receiver for receiving the signals broadcast by the relay station. The mobile station also includes means for determining the phase of the signals received by its first receiver relative to the phase of the signals received by its second receiver, and thereby determine its position relative to the Omega transmitting stations, independent of its distance from the relay station.

Claims

1. In a hyperbolic iso-phase line-of-position navigation system for determining the location of a mobile station in which at least three transmitter stations are located at known fixed locations and sequentially broadcast signals of a predetermined frequency in a predetermined time sequence, the improvement comprising:

a relay station comprising means for receiving signals broadcast by said transmitter stations and means for transmitting a signal whose phase is indicative of the phase of the signals as received at said relay station from said transmitter stations, a first receiver located on said mobile station comprising means for receiving signals broadcast by said transmitter stations, a second receiver located on said mobile station comprising means for receiving the signal transmitted by said relay station, three phase comparison means each corresponding to a respectivE one of said three transmitter stations for determining the phase of the signals received by said first receiver relative to the phase of the signal received by said second receiver, first output means for comparing the phase of said first and second phase comparison means, thereby determining a location along a first line-of-position relative to said first and second transmitter stations, and second output means for comparing the phases of said second and third phase comparison means, thereby determining a location along a second line-of-position relative to said second and third transmitter stations.

2. The invention of claim 1 which further comprises synchronous means synchronized with the predetermined time sequence in which said three transmitter stations broadcast for connecting each of said three phase comparison means to said first and second receivers whenever its respective transmitter station is broadcasting.

3. The invention of claim 2 in which said relay station further comprises a local oscillator having a known frequency different from said predetermined frequency, phase locking means for locking the phase of said local oscillator with the phase of a predetermined one of said transmitter stations, and means for mixing the output signal of said local oscillator with the signals received from said transmitter stations, thereby obtaining a first heterodyne signal whose phase is the same as the phase of the signals from said transmitter stations as received at said relay station.

4. The invention of claim 3 in which said means for transmitting a signal in said relay station comprises means for generating a carrier signal, means for modulating said heterodyne signal onto said carrier signal and means for transmitting the resultant modulated carrier signal.

5. The invention of claim 4 in which said first receiver includes a local oscillator having a known frequency different from said predetermined frequency, phase locking means for locking the phase of said local oscillator with the phase of said predetermined one of said transmitter stations, and means for mixing the output signal of said local oscillator with the signals received from said transmitter stations, thereby obtaining a second heterodyne signal whose phase is the same as the phase of the signals from said transmitter stations as received at said mobile stations.

6. The invention of claim 5 in which the fixed frequency of said local oscillator in said relay station is the same as the fixed frequency of said local oscillator in said first receiver, whereby the frequencies of said first and second heterodyne signals are the same.

7. Mobile receiving means for use in a hyperbolic iso-phase line-of-position navigation system for determining the location of a mobile station carrying said mobile receiving means in which at least three transmitter stations are located at known fixed locations and sequentially broadcast signals of a predetermined frequency in a predetermined time sequence and which includes a relay station for receiving signals broadcast by said transmitter stations and for transmitting a signal whose phase is indicative of the phase of the signals as received at said relay station from said transmitter stations, said mobile receiving means comprising:

a first receiver including means for receiving signals broadcast by said transmitter stations, a second receiver including means for receiving the signal transmitted by said relay station, three phase comparison means each corresponding to a respective one of said three transmitter stations for determining the phase of the signals received by said first receiver relative to the phase of the signal received by said second receiver, first output means for comparing the phases of said first and second phase comparison means, thereby determining a location along a first line-of-position relative to said first and second transmitter stations, and second output means for comparing the phases of said second and third phase comparison means, thereby determining a location along a second line-of-position relative to said second and third transmitter stations.

8. The invention of claim 7 which further comprises synchronous means synchronized with the predetermined time sequence in which said three transmitter stations broadcast for connecting each of said three phase comparison means to said first and second receivers whenever its respective transmitter station is broadcasting.