Multi-beam laser rangefinder

• US 20050174560A1
• Filed: 01/19/2005
• Published: 08/11/2005
• Est. Priority Date: 01/19/2004
• Status: Abandoned Application

• Current Assignee: Rafael - Armament Development Authority Ltd.
• Original Assignee: Rafael - Armament Development Authority Ltd.
• Inventors: Goshtchevsky, Chris, Imber, Amir
• Application Number:
  US11/037,362
• Publication Number:
  US 20050174560A1
• Time in Patent Office: Days
• US Class Current: 356/5.10
• CPC Class Codes: G01S 13/874 Combination of several systems for attitude determination in general G01C, control of attitude G05D1/49
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 13/935 for terrain-avoidance
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/875 for determining attitude
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/933 of aircraft or spacecraft

Abstract

A multi-beam rangefinder system for estimating a range-derived value of an airborne platform relative to the ground. A planar model approximates the ground. The system includes a transmitter arrangement to produce a number of pulses of electromagnetic radiation directed in three or more non-coplanar directions and a sensor arrangement for sensing the pulses of electromagnetic radiation reflected from the ground. The systems also includes a processor arrangement for processing independent measurement of time of flight of the pulses in each of the three or more non-coplanar directions, in order to estimate the range derived value of the airborne platform relative to the ground.

Claims

1. A multi-beam rangefinder system for estimating a range-derived value of an airborne platform relative to the ground, the ground being approximated by a planar model, the system comprising:

(a) a transmitter arrangement configured for producing a plurality of pulses of electromagnetic radiation directed in at least three non-coplanar directions;

(b) a sensor arrangement for sensing said pulses of electromagnetic radiation reflected from the ground; and

(c) a processor arrangement configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate the range derived value of the airborne platform relative to the ground.

2. The system of claim 1, wherein said transmitter arrangement is configured such that said pulses are produced as non-overlapping pulses.

3. The system of claim 2, wherein said transmitter arrangement is configured for producing said pulses sequentially in said three non-coplanar directions.

4. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate an altitude of the airborne platform relative to the ground.

5. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate a rate of a descent or ascent of the airborne platform relative to the ground.

6. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate a rate of an acceleration of the airborne platform relative to the ground.

7. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate a time to hit the ground by the airborne platform.

8. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate a roll of the airborne platform relative to the ground.

9. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate a pitch of the airborne platform relative to the ground.

10. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate an angular velocity of the airborne platform relative to the ground.

11. The system of claim 1 wherein said processor is configured for processing of independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate an angular acceleration of the airborne platform relative to the ground.

12. The system of claim 1, wherein said sensor arrangement includes a single detector, said sensor arrangement having a field of view which is wide enough, such that said single detector detects said pulses of all of said at least three non-coplanar directions.

13. The system of claim 1, further comprising an emergency system configured for being actuated in response to the range derived value exceeding a predefined value.

14. The system of claim 13, wherein said predefined value is a rate of a descent or ascent of the airborne platform relative to the ground.

15. The system of claim 13, wherein said predefined value is a time to hit the ground by the airborne platform.

16. A method for estimating a range-derived value of an airborne platform relative to the ground, the ground being approximated by a planar model, the method comprising the steps of:

(a) producing a plurality of pulses of electromagnetic radiation directed in three non-coplanar directions;

(b) receiving said pulses of electromagnetic radiation reflected from the ground; and

(c) processing independent measurements of time of flight of said pulses in each of said three non-coplanar directions in order to estimate the range derived value of the airborne platform relative to the ground.

17. The method of claim 16, wherein said range defined value is a rate of a descent or ascent of the airborne platform relative to the ground.

18. The method of claim 16, wherein said range defined value is a time to hit the ground by the airborne platform.

19. The method of claim 16, wherein said range defined value is a roll of the airborne platform relative to the ground.

20. The method of claim 16, wherein said range defined value is a pitch of the airborne platform relative to the ground.

21. The method of claim 16, wherein said range defined value is an angular velocity of the airborne platform relative to the ground.

22. The method of claim 16, wherein said range defined value is an angular acceleration of the airborne platform relative to the ground.

23. The method of claim 16, wherein said range defined value is a rate of a descent or ascent of the airborne platform relative to the ground.

24. The method of claim 16, wherein said range defined value is an acceleration of the airborne platform relative to the ground.

25. The method of claim 16, wherein said step of producing is performed by producing said pulses as non-overlapping pulses directed in three non-coplanar directions.

26. The method of claim 25, wherein said step of producing is performed by producing said pulses sequentially in said three non-coplanar directions.

27. The method of claim 16, further comprising the step of actuating an emergency system in response to the range derived value exceeding a predefined value.

28. The method of claim 27, wherein said predefined value is a rate of a descent or ascent of the airborne platform relative to the ground.

29. The method of claim 27, wherein said predefined value is a time to hit the ground by the airborne platform.