Display system and method using weather radar sensing

• US 9,939,526 B2
• Filed: 11/07/2014
• Issued: 04/10/2018
• Est. Priority Date: 09/06/2007
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: Jinkins, Richard D., Rademaker, Richard M., Woodell, Daniel L., Shishlov, Sergey B.
• Primary Examiner(s): Adams, Tashiana R
• Assistant Examiner(s): Seraydaryan, Helena H
• Application Number:
  US14/536,330
• Publication Number:
  US 20160131739A1
• Time in Patent Office: 1,250 Days
• Field of Search: 342 26 B
• CPC Class Codes: G01S 13/953 mounted on aircraft
• CPC Class Codes: G01S 7/12 Plan-position indicators, i.e. P.P.I.
• 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 enhanced vision method uses or an enhanced vision system includes an onboard weather radar system configured to improve angular resolution and/or resolution in range. The onboard weather radar system generates image data representative of the external scene topography of a runway environment associated with radar returns received by the onboard weather radar system. The radar returns are in an X-band or a C-band. The enhanced vision system also includes a display in communication with the onboard weather radar system and is configured to display an image associated with the image data that is generated by the onboard weather radar system. The enhanced vision system can also be used as an enhanced flight vision system.

Claims

1. An airborne weather radar system used for enhanced vision, comprising:

an antenna; and

a control circuit configured to provide radar beams via the antenna toward external surroundings and configured to receive radar returns, wherein the control circuit is configured to process the radar returns to provide image data associated with the external surroundings, wherein the weather radar system has increased range resolution and angular resolution when used for enhanced vision of external scene topography than when used for weather radar sensing functions, the control circuit configured to transmit successive pulses with discrete increasing frequency steps such that radar returns from clutter in an ambiguous range are different from radar returns from targets, the control circuit configured to reject the radar returns from clutter in the ambiguous range, the radar beams being in the X-band or the C-band, the image data being for providing a visual image of external scene topography to a pilot.

2. The system of claim 1, wherein the angular resolution is increased using a beam sharpening technique and de-convolution of a beam point spread function.

3. The system of claim 1, wherein the antenna is a switched aperture antenna, and the control circuit is further configured to process the radar returns to determine a high resolution estimate of a target angle relative to a bore site of the antenna based on switching between transmitting and receiving on a full aperture and transmitting on the full aperture while receiving on a partial aperture.

4. The system of claim 1, wherein the control circuit is configured to provide a perspective enhanced image as the visual image on a display in response to the image data.

5. The system of claim 1, wherein the radar beams are provided as separate pulses with discrete increasing frequency steps.

6. The system of claim 5, wherein the frequency steps hop over restricted or undesired frequencies.

7. A method of providing a real time sensor image, the method comprising:

receiving radar returns from an X-band or C-band airborne weather radar system, the X-band or C-band airborne weather radar system including a switched aperture antenna, wherein the radar returns can be processed to have increased range resolution and angular resolution when used for providing a real time sensor image of external scene topography than when used for weather radar sensing functions;

processing the radar returns to determine a high resolution estimate of a target angle relative to a bore site of the antenna based on switching between transmitting and receiving on a full aperture and transmitting on the full aperture while receiving on a partial aperture; and

filtering the radar returns to identify areas having a reflectivity lower than a predetermined value to provide a visual image of the external scene topography based on the radar returns.

8. The method of claim 7, wherein the radar returns of the X-band or C-band airborne weather radar system comprise a switched aperture, sequential lobing or monopulse weather radar system.

9. The method of claim 7, further comprising displaying an aircraft situation display image on a head down display using the visual image.

10. The method of claim 7, further comprising providing radar beams associated with the radar returns, the radar beams are provided using beam sharpening techniques.

11. The method of claim 10, wherein the beam sharpening techniques comprise a sub-aperture or split aperture technique, the method further comprising using a complex conjugate method to remove Doppler-induced phase changes by cancellation to determine the target angle based on a change in phase center.

12. The method of claim 10, wherein the radar beams are provided using ultra wide band pulses, intra pulse compression, or inter pulse compression.

13. The method of claim 12, wherein the radar beams are provided using stepped frequency compression.

14. An enhanced vision system, comprising:

a weather radar system configured to enhance resolution in range when used for providing an enhanced image of a runway environment than when used for weather radar sensing functions, wherein the weather radar system generates image data representative of the runway environment associated radar returns received by the weather radar system, the radar returns being in an X-band or a C-band, wherein the weather radar system is configured to transmit successive pulses with discrete increasing frequency steps such that radar returns from clutter in an ambiguous range are different from radar returns from targets, the weather radar system configured to reject the radar returns from clutter in the ambiguous range; and

a display in communication with the weather radar system and configured to display an image associated with the radar returns.

15. The system of claim 14, wherein the weather radar system includes processing electronics that are configured to provide increased angular resolution using beam sharpening.

16. The system of claim 14, wherein the display is a head down display or head up display.

17. The system of claim 14, wherein the enhanced vision system is used as an enhanced flight vision system.