NAVIGATION SYSTEM

• US 3,687,556 A
• Filed: 09/18/1970
• Issued: 08/29/1972
• Est. Priority Date: 09/18/1970
• Status: Expired due to Term

• Current Assignee: Harold J. Price, Robert M. Snyder
• Original Assignee: Harold J. Price, Robert M. Snyder
• Inventors: Snyder, Robert M., Price, Harold J.
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Buczinski, S. C.
• Application Number:
  US05/073,357
• Time in Patent Office: 711 Days
• Field of Search: 250/199 356/152,141,1 343/106,112D 340/6 350/285,6,7
• US Class Current: 356/141.3
• CPC Class Codes: G01S 11/04 using angle measurements
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves

Abstract

A position locating method and apparatus are provided which feature continuously rotating a transmitter device for generating a fan-shaped beam signal from a single reference point and monitoring the signal at a position spaced from the reference point with a single detector having a pair of signal receiving members spaced apart a predetermined distance for detecting the passage of the signal sequentially therethrough. The transmitter preferably is a laser beam source which is amplitude modulated with high frequency repetitive pulses to provide precise timing signals for measurement at the receiver and frequency modulated in a linearly increasing fashion during each revolution for providing bearing information. The range, or distance, between the source and the signal-receiving detector, is derived by measuring the time interval elapsing between the receipt of the rotating beam signal respectively by the pair of receiving members. In order to provide signal identification and also information regarding the angular rotational speed of the beam, the beam may also be amplitude modulated at a relatively slow rate.

Claims

1. A navigation system for determining position with respect to a transmitter station, comprising:

a transmitting station including a closed housing having an inlet window in one wall thereof and an outlet window in another wall thereof, a mirror fixedly positioned in said housing and having a reflective surface thereof aligned with said inlet window, a source of energy outside saiD housing for generating a beam of radiation energy through said inlet window and against said reflective surface of said mirror, a lens disposed between said reflective surface of said mirror and said outlet window in said housing for receiving the beam reflected from said reflective surface and spreading the same vertically into a fan-shaped geometry to be passed through said outlet window, and means for rotating said housing at a substantially constant angular velocity; and

a receiver including means for receiving said rotating fanshaped energy beam at a pair of fixedly spaced points, a single detection means responsive to said energy beam received at said space points for producing an output, and circuitry responsive to said detection means output for determining the position of the receiver relative to said transmitting station.

2. The navigation system set forth in claim 1, wherein said transmitting station further includes means for modulating the rotating fan-shaped energy beam being generated with a frequency modulated signal according to a predetermined pattern during each revolution of said beam for providing continuous information regarding the angular position thereof relative to a fixed geographical reference.

3. The navigation system set forth in claim 2, wherein said transmitting station further includes means for modulating the amplitude of the beam being generated with high frequency repetitive pulses to provide precise timing signals for measurement at the receiver.

4. The navigation system set forth in claim 1, wherein said circuitry includes means for timing an interval between the reception of said rotating energy beam at one of said pair of spaced points and reception of said rotating energy beam at the other of said pair of spaced points.

5. The navigation system set forth in claim 1, wherein said rotating fan-shaped beam of energy is a laser beam of infra-red energy.

6. The navigation system set forth in claim 1, wherein said rotating fan-shaped beam of energy being generated is a beam of electromagnetic energy.

7. The navigation system set forth in claim 1, wherein said rotating fan-shaped beam of energy being generated comprises sound waves.

8. A navigation system for determining position with respect to a transmitter station, comprising:

a transmitting station including a closed housing having an inlet window in one wall thereof and an outlet window in another wall thereof, a multi-surfaced mirror disposed in said housing in alignment with said inlet window therein, means for rotating said mirror at a constant speed, a source of energy disposed outside said housing for generating a beam of radiation through said inlet window toward said rotating mirror, whereby the beam reflected therefrom is caused to sweep in a vertical direction, said outlet window being disposed in alignment with said reflected beam, and means for rotating said housing at a constant angular speed; and

a receiver including means for receiving said rotating fan-shaped energy beam at a pair of fixedly spaced points, a single detection means responsive to said energy beam received at said spaced points for producing an output, and circuitry responsive to said detection means output for determining the position of the receiver relative to said transmitting station.

9. The navigation system set forth in claim 1, wherein said receiver comprises:

a central housing, a pair of hollow beam-conducting arms extending in opposite directions from said housing, a beam-receiving input arm connected to the remote end of each of said hollow arms and projecting substantially perpendicularly therefrom, a mirror in each of said hollow arms at the juncture thereof with said beam-receiving arm for reflecting a beam received therein along said hollow arm and in the direction of said housing, a detector in said housing, means for reflecting beams received in said housing toward said detector, and, means for measuring the time interval Between detection of a beam received by said detector from one of said beam-receiving arms and of the same beam received by the other of said beam-receiving arms.

10. The navigation system set forth in claim 9, further including an indicating means in said receiver housing for visually indicating the time interval between detection of the rotating beam by the respective beam-receiving inputs, and, handle means secured to said housing for permitting the same to be held in the hand of an observer.

11. The navigation system set forth in claim 10, wherein said beam of energy is derived from an infra-red source and said detector in said receiver housing is a bolometer.

12. The navigation system set forth in claim 1, wherein said circuitry includes:

means connected to said detection means output for producing first and second discrete signals responsively to changes in received energy occurring upon rotation of said fan-shaped energy beam by said pair of fixedly spaced points, means triggered by one of the first and second discrete signals corresponding to the received energy change due to rotation of said energy beam past the first of said pair of fixedly spaced points, for providing an output signal having a duration determined by an interval between the discrete signals respectively applied thereto, a clock pulse generator, gate means coupled to said clock pulse generator and said means for providing an output signal of a duration equal to the interval between said discrete signals for passing pulses from said generator, and, indicating means for counting the pulses passed by said gate means.

13. The navigation system set forth in claim 12, wherein said indicating means further includes:

multiplier means having said constant angular velocity of said rotating fan-shaped energy beam set thereinto, divider means having the distance separating said pair of fixedly spaced points set thereinto, and, means including said pulse counting means, said multiplier means and said divider means for determining the distance between said transmitting station and said receiver.

14. A transmitting apparatus for a position-determining system, comprising:

a housing having an inlet window in one wall thereof and an outlet window in another wall thereof, a mirror fixedly positioned in said housing having a reflective surface thereof which is aligned with said inlet window, a source of energy outside said housing for generating a beam of radiation through said inlet window and against said reflective surface of said mirror, a lens disposed between said reflective surface of said mirror and said outlet window in said housing for receiving the beam reflected from said reflective surface and spreading the same vertically into a fan-shaped geometry to be passed through said outlet window, and, means for rotating said housing about a predetermined axis at a constant angular velocity.

15. The transmitting apparatus set forth in claim 14, wherein said source of energy is an infra-red laser beam.

16. The transmitting apparatus set forth in claim 14, wherein said lens is a concavo-concave lens.

17. A transmitting apparatus for a position-determining system, comprising:

a housing having an inlet window in one wall thereof and an outlet window in another wall thereof, a multi-surfaced mirror disposed in said housing with the reflective surfaces thereof in alignment with said inlet window therein, means for rotating said mirror at a constant speed, a source of energy disposed outside said housing for generating a beam of radiation through said inlet window toward said rotating mirror, whereby the beam reflected therefrom is caused to sweep in a vertical direction, said outlet window being disposed in alignment with said reflected beam, and, means for rotating said housing at a constant angular speed.

18. The transmitting apparatus set forth in claim 17, wherein said source of energy is An infra-red laser beam.

19. The transmitting apparatus set forth in claim 17, wherein said multi-surfaced mirror is an octagonal-surfaced mirror.

20. A method for determining position with respect to a transmitting station, comprising the steps of:

generating a fan-shaped directional beam of energy from said transmitting station, rotating said fan-shaped energy beam at a substantially constant angular velocity, receiving said rotating fan-shaped energy beam at a pair of spaced-apart receiving stations remote from said transmitting station, detecting the receipt of said energy beam by the first of said receiving stations to receive the same during a given revolution thereof, detecting the receipt of said energy beam by the other of said receiving stations during the next succeeding revolution thereof, measuring the interval of time between detection of said beam by said beam-receiving stations in two successive revolutions, subtracting the time required for rotating said beam through one revolution at said constant angular velocity from said interval of time between said detections, and determining the distance between the transmitting station and the beam-receiving stations by calculating the time required for said beam of energy to pass through the distance separating said receiving stations.