Optical system for detecting and displaying aircraft position and environment during landing and takeoff

• US 7,898,435 B2
• Filed: 02/25/2008
• Issued: 03/01/2011
• Est. Priority Date: 02/23/2007
• Status: Active Grant

• Current Assignee: Rd2, LLC
• Original Assignee: Optical Air Data Systems, LLC
• Inventors: Gatchell, Peter A., Rogers, Philip L., Mamidipudi, Priyavadan
• Primary Examiner(s): PHAM, TOAN NGOC
• Application Number:
  US12/085,310
• Publication Number:
  US 20090140885A1
• Time in Patent Office: 1,100 Days
• Field of Search: 340/973, 340/977, 340/945, 340/949, 340/951, 340/956, 340/963, 340/968, 340/969, 340/970, 356/28, 356/4.08, 356/916, 356/924, 356/73.1, 356/477, 356/478, 356/614, 356/622, 356/906
• US Class Current: 340/973
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G01S 13/913 for landing purposes
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/95 for meteorological use
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A system and method uses light signals to detect and display the position of an airborne vehicle, such as a helicopter, during takeoff or landing or low speed, low altitude operation. A transmitter on the vehicle emits light signals while an optical receiver retrieves reflected light signals. Using light detection and ranging techniques, various parameters, such as altitude, ground speed and relative wind, are calculated based on the Doppler shift within the reflected light signals. The signals are transmitted in three different directions to facilitate the measurements of different Doppler shifts. The parameters are also displayed on a screen or other visual device within the vehicle.

Claims

1. A method for detecting a position of an aircraft comprising:

transmitting light beams;

receiving reflected or backscattered light beams resulting from the transmitting;

measuring differences between the transmitted and received light beams; and

determining parameters based on the measuring to determine the position of the aircraft;

wherein at least one of the transmitted or received light beams, or both, travel through one or more optical fibers.

2. The method of claim 1, wherein the transmitting includes transmitting the light beams at different angles.

3. The method of claim 1, wherein the transmitting includes emitting the light beams from a laser mounted on the aircraft.

4. The method of claim 1, further comprising updating a display according to the parameters.

5. The method of claim 1, further comprising displaying the parameters inside the aircraft.

6. The method of claim 1, wherein the measuring includes determining a Doppler shift from changes in frequency between the transmitted and received light beams.

7. The method of claim 1, wherein the parameters include altitude, ground speed, magnetic wind, relative wind, vertical velocity, airspeed, or ground velocity.

8. The method of claim 1 further comprising:

comparing the parameters to operating parameters; and

controlling operation of the aircraft based on the comparing.

9. The method of claim 1, further comprising:

displaying the parameters such that an operator of the aircraft performs take-off or landing of the aircraft using the displayed parameters if the operator has substantially limited or no ground visibility.

10. The method of claim 9, wherein the displaying of the parameters is continually updated.

11. A method comprising:

receiving at an aircraft reflected or backscattered light beams based on light beams transmitted from the aircraft, such that at least one of the transmitted or received light beams, or both, travel through one or more optical fibers;

measuring differences between the transmitted and received light beams;

determining parameters relating to a position of the aircraft according to the measured differences; and

displaying the parameters in the aircraft.

12. The method of claim 11, further comprising:

repeating the transmitting, receiving, and measuring; and

updating the displaying based on subsequent ones of the measured differences.

13. The method of claim 11, further comprising using altitude, laser altitude, ground speed, relative wind, vertical velocity, airspeed, heading, or ground velocity as the parameters.

14. The method of claim 11, further comprising using relative wind velocity or magnetic wind velocity as the parameters.

15. The method of claim 11, further comprising using a heads-up display as the display.

16. The method of claim 11, further comprising:

performing take-off or landing of the aircraft using the displayed parameters if an operator has substantially limited or no ground visibility.

17. A system for detecting position of an aircraft comprising:

a transmitter configured to transmit a light beam from the aircraft;

an optical receiver configured to receive reflected or backscattered light beams; and

a measuring device configured to compare the transmitted and received beams and to calculate parameters with respect to the position of the object,

wherein at least one of the transmitter and the optical receiver comprises an optical fiber configured to guide the transmitted or received light beams, or both.

18. The system of claim 17, further comprising a gyroscope to provide a reference for the transmitter and optical receiver, and to provide an angle of transmission for the light beams.

19. The system of claim 17, wherein the parameters include altitude, ground speed, magnetic wind, relative wind, vertical velocity, airspeed, or ground velocity.

20. The system of claim 17, wherein the measuring device is further configured to:

compare the parameters to operating parameters; and

control operation of the aircraft based on the comparing.

21. The system of claim 17, further comprising:

a display configured to display the parameters, wherein an operator of the aircraft performs take-off or landing of the aircraft using the displayed parameters if the operator has substantially limited or no ground visibility.

22. The system of claim 21, wherein the display comprises a heads-up display.