System and method for aircraft altitude measurement using radar and known runway position

• US 8,077,078 B1
• Filed: 07/25/2008
• Issued: 12/13/2011
• Est. Priority Date: 07/25/2008
• 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., Jinkins, Richard D., Rademaker, Richard M., McCusker, Patrick D.
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US12/180,293
• Time in Patent Office: 1,236 Days
• Field of Search: 342/118, 342120-123, 342/146, 342/147, 342165-175, 342192-197, 342/352, 342356-358, 342 33- 35, 701 1- 18, 701300-302, 340/945, 340/947, 340/951, 340/952
• US Class Current: 342/120
• CPC Class Codes: G01S 13/46 Indirect determination of position data
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06

Abstract

A method of and system for determining the altitude of an aircraft can use a relative altitude estimate using information from an onboard radar. The altitude can be referenced to a runway for landing operations. The radar can produce relative altitude information from the range to the landing point and a precision estimation of the vertical angle to the landing point. The vertical angle estimate can be made with a phase processing antenna/radar system.

Claims

1. A method of determining an altitude of an aircraft in response to a runway altitude of a runway and a radar sweep by a radar system, the method comprising:

receiving first data associated with an aircraft position;

receiving second data associated with a runway position and the runway altitude;

receiving third data associated with a radar return from the runway;

determining a range between the aircraft and the runway using the first and second data;

determining a vertical angle between the runway and the aircraft using the third data; and

determining the altitude of the aircraft based on the vertical angle, the range, and the runway altitude.

2. The method of claim 1, wherein the aircraft and runway positions are absolute or relative to each other.

3. The method of claim 1, wherein the altitude of the aircraft is referenced to the runway and used directly.

4. The method of claim 1, further comprising:

using the determined altitude of the aircraft to confirm or adjust a sensed altitude of the aircraft.

5. The method of claim 4, wherein the sensed altitude is provided by a pressure-based altitude sensor, a GPS device, or an inertial-based altitude sensor.

6. The method of claim 1, wherein the vertical angle is determined using a sub-aperture technique.

7. The method of claim 1, wherein the radar sweep comprises at least one of a vertical sweep, a diagonal sweep, or a horizontal sweep.

8. An aircraft radar system for an aircraft, comprising:

an antenna configured to receive a radar return from a runway associated with a radar sweep;

processing electronics configured to determine a relative altitude of the aircraft using an angle associated with the radar return and a range between the runway and the aircraft, and

configured to determine a first altitude of the aircraft by summing the relative altitude and an altitude of the runway.

9. The aircraft radar system of claim 8, wherein the first altitude of the aircraft is determined and used directly.

10. The aircraft radar system of claim 8, wherein the radar sweep comprises at least one of a vertical sweep, a diagonal sweep, and a horizontal sweep.

11. The aircraft radar system of claim 8, wherein the first altitude of the aircraft is used to confirm or adjust a sensed altitude.

12. The aircraft radar system of claim 11, wherein the sensed altitude is provided by a pressure-based altitude sensor, a GPS device, or an inertial-based altitude sensor.

13. The aircraft radar system of claim 8, wherein the radar system uses a sub-aperture technique.

14. The aircraft radar system of claim 8, wherein the radar system is a weather radar system.

15. The aircraft radar system of claim 8, further comprising:

a memory configured to store the altitude of the runway and a position of the runway, data associated with the radar return, and/or computer code for the processing electronics.

16. The aircraft radar system of claim 8, further comprising:

a transceiver configured to receive the altitude of the runway and a position of the runway from a remote source.

17. An apparatus, comprising:

means for receiving third data associated with a radar return from a runway; and

means for determining a range between an aircraft and the runway using first data associated with an aircraft position and second data associated with a runway position and a runway altitude, calculating a vertical angle between the runway and the aircraft using the third data, and determining an altitude of the aircraft based on the vertical angle, the range, and the runway altitude.

18. The apparatus of claim 17, wherein the altitude of the aircraft is determined and used directly.

19. The apparatus of claim 17, wherein the altitude of the aircraft is used to confirm or adjust a sensed altitude of the aircraft.

20. The apparatus of claim 19, wherein the sensed altitude is provided by a pressure-based altitude sensor, a GPS device, or an inertial-based altitude sensor.