System and method for a terrain database and/or position validation

• US 7,859,449 B1
• Filed: 09/06/2007
• Issued: 12/28/2010
• 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: Woodell, Daniel L., Rademaker, Richard M., Jinkins, Richard D., Dickerson, Charles J., Meyer, Nathanael A.
• Primary Examiner(s): Sotomayor; John B
• Application Number:
  US11/900,002
• Time in Patent Office: 1,209 Days
• Field of Search: 342/65, 342/26.R, 342/26.B, 342/123, 342/195
• US Class Current: 342/65
• CPC Class Codes: G01S 13/935 for terrain-avoidance
• CPC Class Codes: G01S 13/953 mounted on aircraft
• 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

An aircraft weather radar system can be used with a terrain avoidance system. The aircraft weather radar system is coupled to an antenna. A processor receives radar returns received by the antenna. The processor determines terrain elevation estimates for use with the terrain avoidance system from the radar returns. The terrain elevation estimates are compared to stored terrain elevation data used with the terrain avoidance system to verify position or to check the integrity of the stored elevation data. The processor can be part of a terrain avoidance system, a weather radar system, a navigation system, or can be a standalone system.

Claims

1. A method of using a terrain avoidance system on an aircraft including a weather radar system, the method comprising:

generating estimates representing terrain elevation using the weather radar system;

receiving data from a terrain elevation database; and

providing a warning if the estimates and the data indicate a position error or an error in the estimates or the data.

2. The method of claim 1, wherein the estimates are determined using multiple scan techniques.

3. The method of claim 1, wherein the power ratio associated with weather radar returns is used to determine the estimates.

4. The method of claim 3, wherein the weather radar returns are from multiple beams swept in azimuth and with different beam elevations.

5. The method of claim 1 wherein the phase difference of two or more beams is used to determine the estimates.

6. The method of claim 1, wherein the warning indicates a position error.

8. The method of claim 1, wherein the warning is provided in response to a hill climbing algorithm.

7. A method of using a terrain avoidance system on an aircraft including a weather radar system, the method comprising:

generating estimates representing terrain elevation using the weather radar system;

receiving data from a terrain elevation database; and

providing a warning if the estimates and the data indicate a position error or an error in the estimates or the data, wherein the warning is provided in response to an algorithm for comparing radar shadows associated with the estimates to the data.

9. An aircraft weather radar system for use with a terrain avoidance system, the weather radar system being coupled to an antenna, the weather radar system comprising:

a processor for receiving radar returns received by the antenna, the processor determining terrain elevation data for use with the terrain avoidance system from the radar returns, the terrain elevation data being compared to stored data used with the terrain avoidance system to verify position or to check the integrity of the stored data.

10. The system of claim 9, wherein the position is derived from global positioning system (GPS) signals, or other position determining means and the position is compared to a position determined from the terrain data.

11. The system of claim 9, wherein the returns include weather radar returns, wherein the processor receives the weather radar returns associated with weather, wherein the processor removes the weather radar returns before determining the terrain elevation data.

12. The system of claim 9, wherein the weather radar system is a multi-scan system.

13. The system of claim 9, wherein a warning is provided when the terrain elevation data does not match the stored data.

15. The system of claim 9, wherein the processor matches the terrain elevation data to the stored data using a fourth order algorithm, the fourth order algorithm being executed by the processor.

16. The system of claim 15, wherein the fourth order algorithm matches the stored data and the terrain elevation data with respect to a left, right orientation, an up and a down orientation, a rotationally clockwise, rotationally counterclockwise orientation, wherein the processor matches the terrain elevation data to the stored data.

14. An aircraft weather radar system for use with a terrain avoidance system, the weather radar system being coupled to an antenna, the weather radar system comprising:

a processor for receiving radar returns received by the antenna, the processor determining terrain elevation data for use with the terrain avoidance system from the radar returns, the terrain elevation data being compared to stored data used with the terrain avoidance system to verify position or to check the integrity of the stored data, wherein the terrain elevation data is related to radar shadows.

17. The system of claim 14, wherein the processor executes a hill climbing algorithm to match the terrain elevator data to the stored data.

18. An apparatus for an aircraft terrain avoidance system, the apparatus comprising:

a first input for receiving terrain estimates derived from a weather radar system;

a second input for receiving terrain data stored onboard the aircraft; and

a means for comparing the terrain elevation estimates derived from a weather radar system and the terrain elevation data.

19. The apparatus of claim 18, wherein the first input is within an onboard weather radar system.

20. The apparatus of claim 18, wherein a fourth order hill climbing algorithm is used by the means for comparing.