Terrain data retrieval system

• US 20020113719A1
• Filed: 09/17/2001
• Published: 08/22/2002
• Est. Priority Date: 07/31/1995
• Status: Active Grant

• Current Assignee: Hans R. Muller, Kevin J. Conner, Steven C. Johnson
• Original Assignee: Hans R. Muller, Kevin J. Conner, Steven C. Johnson
• Inventors: Johnson, Steven C., Conner, Kevin J., Muller, Hans R.
• Granted Patent: US 6,710,723 B2
• Time in Patent Office: Days
• US Class Current: 340/961
• CPC Class Codes: G01S 13/953 mounted on aircraft
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G01S 7/12 Plan-position indicators, i.e. P.P.I.
• CPC Class Codes: G01S 7/22 Producing cursor lines and indicia by electronic means
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• 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 terrain-awareness system (TAS) provides LOOK-AHEAD/LOOK-DOWN as well as LOOK-UP terrain advisory and warning indications to the pilot of an aircraft of a hazardous flight condition. The TAS includes an airport data base as well as a terrain data base that is structured to provide various resolutions depending on the topography of the particular geographic area of interest. Navigational data from a satellite-based navigational system, such as a global positioning system (GPS), is used to provide a LOOK-AHEAD/LOOK-DOWN and LOOK-UP terrain advisory and terrain warning indications based upon the current position and projected flight path of the aircraft. Since the terrain advisory and the warning signals are a function of the flight path of the aircraft, nuisance warnings are minimized.

Claims

1. A warning system for an aircraft comprising:

first means for receiving signals representative of the flight path angle;

second means for receiving signals from a predetermined satellite-based navigation system representative of the position of the aircraft;

third means for receiving signals representative of the altitude of an aircraft;

means for storing data representative of predetermined terrain information; and

means responsive to said first means, said second means, said third means and said storing means for generating a first warning signal of a hazardous flight condition as a function of the position of the aircraft relative to said predetermined terrain information and the flight path angle of aircraft for a predetermined area relative to the aircraft.

2. A warning system as recited in claim 1, wherein said predetermined satellite-based navigation system is the global positioning system GPS.

3. A warning system as recited in claim 1, wherein said predetermined area includes an area below the aircraft.

4. A warning system as recited in claim 1, wherein said predetermined area includes area in front of the aircraft.

5. A warning system as recited in claim 1, wherein said predetermined area includes area above the aircraft.

6. A warning system for providing an indication to the pilot of an aircraft of the proximity of terrain to the aircraft, the warning system comprising:

means for receiving signals representative of the position of the aircraft;

means for storing data representative of terrain elevations, obstacle elevations and one or more predetermined reference points for one or more predetermined geographical areas;

means for receiving signals representative of a flight path angle of the aircraft;

means for determining the distance of the aircraft relative to one of said one or more predetermined reference points;

first comparing means for comparing the flight path angle of the aircraft with a first fixed predetermined datum having a first predetermined angle relative to a horizontal axis; and

first generating means for generating first advisory boundary signals defining a plurality of first advisory boundaries as a predetermined function of said first predetermined angle of said first fixed reference predetermined datum and said distance to said predetermined reference point for a first predetermined distance in front of said aircraft when said flight path angle is less than said first predetermined angle of said first predetermined fixed datum and generating said first advisory boundary signals as a predetermined function of said flight path angle and said distance to said predetermined reference point for said first predetermined distance in front of the aircraft when said flight path angle is not less than said first predetermined angle of said first predetermined fixed datum.

7. A warning system as recited in claim 6, further including means for determining when said aircraft is descending and wherein said first generating means includes means for generating one of said plurality of first advisory boundaries as a predetermined function of a first variable reference datum for said first predetermined distance in front of said aircraft, said first variable reference datum being a predetermined function of said flight path angle.

8. A warning system as recited in claim 7, further including means for receiving signals representative of the ground speed of the aircraft, and wherein said first predetermined distance is a predetermined function of the ground speed of the aircraft.

9. A warning system as recited in claim 6, wherein said first generating means includes means for generating first warning boundary signals defining a plurality of first warning boundaries as a predetermined function of said first predetermined angle of said first fixed reference datum and the distance to said predetermined reference point for a second predetermined distance in front of the aircraft when said flight path angle is less than said first predetermined angle of said first predetermined reference datum and generating said first warning boundary signals as a predetermined function of said flight path angle and the distance to said predetermined reference point for said second predetermined distance in front of the aircraft when said flight path angle is not less than said first predetermined angle of said predetermined fixed datum.

10. A warning system as recited in claim 9, further including means for determining when said aircraft is descending and wherein said first generating means includes means for generating a first warning boundary as a predetermined function of a second variable reference datum for said second predetermined distance in front of said aircraft, said second variable reference datum being a predetermined function of said flight path angle.

11. A warning system as recited in claim 9, further including second comparing means for comparing the flight path angle with a second predetermined fixed datum at a second predetermined angle, means for receiving a signal representative of the vertical speed of the aircraft, and second generating means for generating second advisory boundary signals defining a plurality of second advisory boundaries as a predetermined function of said second predetermined fixed datum, the distance to said predetermined reference point and the vertical speed of the aircraft for a first predetermined distance in front of the aircraft when said flight path angle is less than said second predetermined angle of said second predetermined fixed datum and generating said second advisory boundary signals as a predetermined function of said flight path angle, the distance to said predetermined reference point and the vertical speed of the aircraft for said first predetermined distance when said flight path angle is greater than said second predetermined angle of said second predetermined fixed datum.

12. A warning system as recited in claim 11, wherein said second generating means includes means for generating second warning boundary signals defining a plurality of second warning boundaries as a predetermined function of said second predetermined fixed datum, the distance to said second predetermined reference point and the vertical speed of the aircraft for a second predetermined distance when said flight path angle is less than said second predetermined angle of said second predetermined fixed datum and generating said second warning boundary signals as a predetermined function of said flight path angle, the distance to said predetermined reference point and the vertical speed of the aircraft for said second predetermined distance when said flight path angle is greater than said second predetermined angle of said second predetermined fixed datum.

13. A warning system as recited in claim 9, further including means for inhibiting said first generating means as a predetermined function of one or more predetermined altitudes.

14. A warning system as recited in claim 13, wherein at least one of said one or more predetermined altitudes may be variable.

16. A warning system as recited in claim 15, further including means for receiving signals representative of the flight path angle of the aircraft and wherein said first generating means includes means for generating a second segment of said first advisory envelope extending from said first segment of said first advisory envelope along a first predetermined fixed datum at a first predetermined angle for a first predetermined distance in front of said aircraft, when said flight path angle is less than said first predetermined angle, wherein said second segment of said first advisory envelope extends from said first segment of said first advisory envelope at the flight path angle for said first predetermined distance when said flight path angle is greater than said first predetermined angle.

17. A warning system as recited in claim 16, further including means for receiving signals representative of the ground speed of the aircraft and wherein said first predetermined distance is a predetermined function of said ground speed of said aircraft.

18. A warning system as recited in claim 17, further including means for expanding said first advisory envelope as a predetermined function of a first predetermined variable datum.

19. A warning system as recited in claim 18, further including means for determining when said aircraft is descending and expanding said first advisory envelope as a predetermined function of said first predetermined variable datum, wherein said first predetermined variable datum is a predetermined function of said flight path angle.

20. A warning system as recited in claim 15, further including means for generating a first warning envelope for a second predetermined distance in front of said aircraft, said first warning envelope having a plurality of segments, one of said segments extending downwardly from the current position and altitude of the aircraft for a distance which varies as a predetermined function of the distance of the aircraft to a predetermined reference point defining a first segment of said first warning envelope.

21. A warning system as recited in claim 20, further including means for receiving signals representative of the flight path angle of the aircraft and wherein said first generating means includes means for generating a second segment of said first warning envelope extending from said first segment of said first warning envelope along a first predetermined fixed datum at a first predetermined angle for a second predetermined distance in front of the aircraft, when said flight path angle is less than said first predetermined angle, wherein said second segment of said first warning envelope extends from said first segment of said first warning envelope at the flight path angle for said second predetermined distance when said flight path angle is greater than said first predetermined angle.

22. A warning system as recited in claim 21, further including means for determining when said aircraft is descending and expanding said first warning envelope as a predetermined function of said second predetermined variable datum, said second predetermined variable datum being a predetermined function of said flight path angle.

24. A warning system as recited in claim 23, wherein said providing means includes means for determining the relationship between the flight path angle and a predetermined first datum and generating a first warning signal as a function of the relationship between the flight path angle and said first predetermined datum.

25. A warning system as recited in claim 24, wherein said providing means includes means for determining the relationship between the flight path angle and a predetermined second datum and generating a second warning signal as a function of the relationship between said flight path angle and said second predetermined datum.

26. A warning system as recited in claim 25, wherein said first predetermined datum and said second predetermined datum are configurable.

27. A warning system as recited in claim 23, wherein said predetermined distance is a function of the airspeed of the aircraft.

28. A warning system as recited in claim 23, wherein said first warning signal defines a plurality of boundaries relative to the current position and altitude of the aircraft.

29. A warning system as recited in claim 28, further including means for modifying said boundaries under predetermined conditions.

30. A warning system as recited in claim 29, wherein said modifying means includes means for modifying said boundaries as a function of the flight path angle of the aircraft.

31. A warning system as recited in claim 30, further including means for inhibiting said modifying means when said flight path angle is greater than a predetermined angle.

32. A warning system as recited in claim 29, further including means for modifying said first datum as a function of the flight path angle of the aircraft.

15. A warning system for providing an indication to the pilot of an aircraft of the proximity of terrain to the aircraft, the warning system comprising:

means for receiving signals representative of the position of the aircraft;

means for storing terrain data representative of the terrain elevations, obstacle elevations and one or more predetermined reference points for one or more predetermined geographical areas;

means for receiving signals representative of the altitude of the aircraft;

means for determining the current altitude of the aircraft;

first generating means for generating a first advisory envelope, said first advisory envelope having a plurality of segments, one of said segments extending downwardly from the current position and altitude of said aircraft for a predetermined distance which varies as a predetermined function of the distance of the aircraft to a predetermined reference point defining a first segment of said first advisory envelope.

23. A warning system for an aircraft comprising:

means for receiving signals representative of the flight path angle of the aircraft;

means for receiving signals representative of the position of the aircraft;

means for receiving signals representative of the altitude of an aircraft;

means for storing data representative of predetermined terrain information; and

means for generating a first warning signal of a hazardous flight condition as a function of the position of the aircraft relative to said predetermined terrain information and the flight path angle of aircraft and a predetermined distance in front of said aircraft.