System and method for sensor-based terrain avoidance

• US 8,515,600 B1
• Filed: 09/06/2007
• Issued: 08/20/2013
• Est. Priority Date: 09/06/2007
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: McCusker, Patrick Dennis
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): Shafi, Muhammad
• Application Number:
  US11/851,323
• Time in Patent Office: 2,175 Days
• Field of Search: 701 1- 18, 701/120, 701/300, 701/301, 340/970, 340/961, 340/963, 340/968, 340/945, 340/971, 340/977, 340/979, 340/967, 340/951, 342 26 R- 26 D, 342/175, 342/176, 342 89-103, 342192-197, 342 61- 65, 342/26.B, 342/33, 342/47, 342118-146, 342/113, 342/357.53, 244/181, 244/76.R, 244/90.R, 244/220, 244/221, 244179-197
• US Class Current: 701/9
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• 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 13/953 mounted on aircraft
• CPC Class Codes: G01S 7/04 Display arrangements
• 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 for a terrain awareness warning system. The system includes a radar system configured to transmit a first radio frequency wave and receive a second radio frequency wave and a display for receiving a display signal representative of a terrain and a terrain awareness warning system. The terrain awareness warning system includes a forward-looking terrain logic configured to be in communication with the radar system and to process a terrain signal from the radar system.

Claims

1. In an aircraft including a forward-looking radar system configured to transmit and receive forward radar signals, a downward-looking radar system, and a display for receiving a display signal representative of a terrain, a terrain awareness system comprising:

a forward-looking terrain logic configured to be in communication with the forward-looking radar system and the downward-looking radar system, wherein the forward-looking terrain logic receives an altitude derived from a downward-looking radar signal from the downward-looking radar system, wherein the altitude represents a first distance between the terrain below the aircraft at a point where the downward looking radar signal strikes the terrain and the forward-looking terrain logic determines a second distance to a terrain cell from data derived from the forward radar signals, the terrain cell being in forward line of site of the aircraft, wherein the forward-looking terrain logic provides a warning if the altitude is less than threshold height, or if the second distance is less than a threshold distance, wherein the warning is provided without using a stored terrain data base.

2. The system of claim 1, wherein the forward-looking terrain logic is configured to transmit an alert signal to a display.

3. The system of claim 1, wherein the terrain awareness system further comprises a terrain display device configured to transmit a terrain image signal to the display based on a terrain signal.

4. The system of claim 1, wherein the terrain awareness system further comprises a premature descent alert logic.

5. The system of claim 1, wherein the terrain awareness system is in communication with at least one of a global positioning system, an inertial reference system and an air data computer.

6. In an aircraft including a first radar system configured to transmit a first radio frequency wave and receive a second radio frequency wave, a downward-looking radar system and a display for receiving a display signal representative of a terrain, a terrain awareness warning system comprising:

a means for providing a forward-looking terrain warning configured to be in communication with the first radar system and the downward-looking radar system to process a radar signal from the first radar system, wherein the means receives an altitude derived from a downward-looking radar signal of the downward-looking radar system, the altitude being a first distance between the terrain and the aircraft at a point where downward looking radar signal strikes the terrain, wherein the means provides a warning if the altitude is less than a threshold height, or if a terrain cell is within a second distance to the aircraft, the terrain cell being determined from data derived from the second radio frequency wave and associated with terrain in a forward line of site of the aircraft, wherein the warning is provided without comparing an aircraft position to a stored terrain data base.

7. The system of claim 6, wherein the means for providing is configured to transmit an alert signal to a display based on a terrain signal.

8. The system of claim 6, wherein the terrain awareness warning system further comprises a means for providing terrain display logic configured to transmit a terrain image signal to a display based on a terrain signal.

9. The system of claim 6, wherein the terrain awareness warning system further comprises a means for providing premature descent alert logic.

10. The system of claim 6, wherein the terrain awareness warning system is in communication with at least one of a global positioning system, an inertial reference system and an air data computer.

11. In an aircraft including a forward looking weather radar system configured to transmit and receive forward radar signals, a radio altimeter and a display for receiving a display signal representative of a terrain, an alert system comprising:

a processor receiving an altitude derived from the radio altimeter, wherein the processor determines a distance to a terrain from data derived from the forward radar signals, the terrain being in a forward line of site of the aircraft, wherein the processor provides an alert in response to the altitude being less than threshold height or the distance being less than a threshold distance, wherein the alert or warning is provided without using a terrain data base.

12. The system of claim 11, wherein terrain data derived from the radar altimeter and the data derived from the forward-looking weather radar system is compared to verify whether the aircraft has passed over a terrain location.

13. The system of claim 12, wherein the terrain location is one or more terrain cells.

14. The system of claim 13, wherein the terrain data is temporarily stored until the aircraft passes over the terrain location.

15. The warning system of claim 14, wherein the terrain data is provided to an off-board computer, the off-board computer providing a discrepancy report.

16. The system of claim 11, wherein the warning system further comprises a terrain display device configured to transmit a terrain image signal to the display based on a terrain signal.

17. The system of claim 11, wherein the terrain location warning system further comprises a premature descent alert logic.

18. The system of claim 11, wherein the warning system further comprises a ground proximity alert logic.

19. The system of claim 11, wherein a height of the terrain is determined by discontinuities or change in slope.

20. The system of claim 19, wherein the height is determined by change in slope.