Method and apparatus for predictive altitude display

• US 7,057,549 B2
• Filed: 03/09/2005
• Issued: 06/06/2006
• Est. Priority Date: 10/10/2000
• Status: Expired due to Fees

• Current Assignee: Nighthawk Flight Systems Incorporated
• Original Assignee: Sandel Avionics Inc.
• Inventors: Block, Gerald J.
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US11/076,794
• Publication Number:
  US 20050248481A1
• Time in Patent Office: 454 Days
• Field of Search: 342/65, 342/176, 342179-183, 342/197, 342120-123, 340/955, 340/945, 340/970, 701/4
• US Class Current: 342/65
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 13/886 for alarm systems alarms with electrical actuation G08B13/22
• CPC Class Codes: G01S 13/93 for anti-collision purposes
• CPC Class Codes: G01S 13/935 for terrain-avoidance
• CPC Class Codes: G01S 7/062 in which different colours are used

Abstract

Embodiments of the invention provide a method and apparatus for indicating aircraft height relative to an obstruction in a terrain awareness warning system. The method includes receiving data indicative of geographic features of an obstruction, lateral distance of the geographic feature from an aircraft, height and flight path of the aircraft, calculating a projected height of the aircraft at the location of the obstruction using the data, generating a result signal, and displaying a colored indication on a display screen based on the result signal. The apparatus includes inputs for signals from instruments measuring height, flight path, and location of an aircraft, as well as an input for an instrument providing information about geographic features of terrain surrounding the aircraft. The apparatus includes a means for employing the signals to calculate an effective height of the aircraft relative to the terrain, and a screen display for graphically displaying the results of the calculation.

Claims

1. A method for providing an indication of aircraft height relative to an obstruction in a terrain awareness warning system, comprising:

receiving a first datum indicative of a feature of an obstruction;

receiving a second datum indicative of a distance of the feature from an aircraft;

receiving a third datum indicative of a height of the aircraft;

receiving a fourth datum indicative of a speed of the aircraft;

calculating a projected height of the aircraft at the location of the obstruction using the first through fourth data; and

generating a result signal based on the projected height and the first datum.

2. The method of claim 1, wherein the first datum is a height of the obstruction.

3. The method of claim 1, wherein the receiving a fourth datum step further comprises:

resolving the speed of the aircraft into components including a lateral speed and a vertical speed.

4. The method of claim 2, further comprising calculating a pitch angle of the aircraft from the received fourth datum.

5. The method of claim 4, further comprising calculating an effective altitude of the aircraft by adding to the third datum a value equal to the second datum multiplied by the tangent of the pitch angle.

6. The method of claim 5, further comprising generating a first alert signal if the effective altitude is less than the sum of the first datum and a safety elevation.

7. The method of claim 6, wherein the safety elevation is zero.

8. The method of claim 6, further comprising sounding an audible alarm as the first alert signal.

9. The method of claim 6, further comprising displaying a first colored indication at a display location corresponding to the second datum as the first alert signal.

10. The method of claim 9, wherein the colored indication is a red area.

11. The method of claim 5, further comprising generating a second alert signal if the effective altitude is greater than the sum of the first datum and a safety elevation but less then a sum of the first datum, the safety elevation, and a first distance.

12. The method of claim 11, further comprising displaying a second colored indication at a display location corresponding to the second datum as the second alert signal.

13. A computer program, stored in a machine-readable format, for a terrain awareness warning system, for causing a computer to:

receive a first datum indicative of a feature of an obstruction;

receive a second datum indicative of a distance of the feature from an aircraft;

receive a third datum indicative of a height of the aircraft;

receive a fourth datum indicative of a speed of the aircraft;

calculate a projected height of the aircraft at the location of the obstruction using the first through fourth data; and

generate a result signal based on the projected height and the first datum.

14. A apparatus for providing an indication of aircraft height relative to an obstruction in a terrain awareness warning system, comprising:

a first input for a first signal from an instrument measuring a height of an aircraft;

a second input for a second signal from an instrument measuring a location of the aircraft;

a third input for a third signal from an instrument providing information about features of terrain surrounding the aircraft;

a fourth input for a fourth signal from an instrument measuring a speed of the aircraft; and

means for employing the signals from the first through fourth inputs to calculate an effective height of the aircraft relative to at least the third input.

15. The apparatus of claim 14, wherein the instrument measuring a height of the aircraft and the instrument measuring a location of the aircraft is an altimeter and wherein the instrument providing information about geographic features of terrain surrounding the aircraft and the instrument measuring a speed of the aircraft is an aid to navigation.

16. The apparatus of claim 15, wherein the aid to navigation is a global positioning system unit.

17. The apparatus of claim 14, wherein the first through fourth inputs form at least a portion of a parallel data bus.

18. The apparatus of claim 14, wherein the first though fourth inputs form at least a portion of a serial data stream.

19. A method of performing terrain awareness warning for an aircraft, comprising:

collecting data of obstructions in the vicinity of an aircraft;

collecting data of the distance and bearing of the obstructions from the aircraft;

collecting data of the height and speed of the aircraft;

calculating a projected height of the aircraft at the location of each of the obstructions based on the collected data of the height and speed of the aircraft;

generating result signals based on the projected height, the collected data of obstructions, and the bearing of the obstructions; and

displaying indications on a display screen with respect to bearing based on the generated result signals.

20. A method for providing an indication of lateral aircraft position relative ot an obstruction in a terrain awareness warning system, comprising:

receiving a first datum indicative of a bearing of an obstruction relative to an aircraft;

receiving a second datum indicative of a distance of the obstruction from the aircraft;

receiving third datum indicative of a speed of the aircraft;

calculating a projected flight path of the aircraft relative to the obstruction using the first through third data and determining a distance between the projected flight path and the obstruction at a series of points along the projected flight path; and

generating a result signal based on the determined distance.