Method for producing 3D perspective view avionics terrain displays

• US 6,862,501 B2
• Filed: 10/28/2002
• Issued: 03/01/2005
• Est. Priority Date: 10/28/2002
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: He, Gang
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US10/282,709
• Publication Number:
  US 20040083038A1
• Time in Patent Office: 855 Days
• Field of Search: 701/3, 701/9, 701/10, 701/14, 701/1, 701/6, 345/426, 345/420, 345/421, 345/419, 345/423, 345/606, 345/422, 345/441, 345/502, 345/503, 345/522, 345/440, 345/440.1, 340/961, 340/963, 340/973, 340/945, 340/971, 340/949, 340/968, 340/980, 342/35, 342/65, 342/63, 342/26, 342/58, 342/268
• US Class Current: 701/3
• CPC Class Codes: G06T 15/04 Texture mapping
• CPC Class Codes: G06T 17/20 Finite element generation, e.g. wire-frame surface description, tesselation
• CPC Class Codes: G06T 2210/36 Level of detail
• CPC Class Codes: Y10S 707/99936 Pattern matching access

Abstract

Methods for generating information for displaying terrain on an aircraft display system that significantly reduces the computation and data load for producing the terrain display. This is accomplished through the use of intelligent level of detail control that computes and displays terrain and dynamic on-terrain perspective projection lines and distance rings aligned with the aircraft heading for depth perception and relative altitude awareness. The terrain details are processed and displayed in a manner that shows all significant terrain features, e.g., peaks, towers, and the like, but through the use of nonlinear error bound geometric morphing, coupled with triangle binary tree based terrain mesh generation, the polygon count, and thus the computational load, are significantly reduced, while visual fidelity is maintained.

Claims

1. In an aircraft display system having a processor for processing data for displaying terrain, a method for reducing the required computational load on the processor comprising:

obtaining terrain data from a data source, and

using the terrain data to construct a polygon terrain mesh, the polygon terrain mesh having error bounds that increase non-linearly from a viewing location.

2. A method as set forth in claim 1 wherein the terrain data comprises a terrain data patch having terrain location and terrain elevation data.

3. A method as set forth in claim 2 wherein the terrain data patch is used to compute a color texture map using absolute terrain elevation data.

4. A method as set forth in claim 3 wherein the terrain data patch is used to construct an error bound array for a triangle binary tree based terrain patch, and the polygon terrain mesh is constructed using the error bound array.

5. A method as set forth in claim 4 wherein the color texture map is loaded onto the polygon terrain mesh to produce a color polygon terrain representation for display.

6. In an aircraft display system having a processor for processing data for displaying terrain, a method for reducing the required computational load on the processor comprising:

obtaining terrain data from a data source,

using the terrain data to construct a polygon terrain mesh, the polygon terrain mesh having error bounds that increase non-linearly from a viewing location providing higher resolution nearer the viewing location,

computing geo-morphing parameters based on the error bound, and

using the parameters to control geo-morphing range and duration to ensure visually smooth transitions from lower resolution displays to higher resolution displays.

7. A method as set forth in claim 6 wherein the terrain data comprises a terrain data patch having terrain location and terrain elevation data.

8. A method as set forth in claim 7 wherein the terrain data patch is used to compute a color texture map using absolute terrain elevation data.

9. A method as set forth in claim 8 wherein the terrain data patch is used to construct an error bound array for a triangle binary tree based terrain patch, and the polygon terrain mesh is constructed using the error bound array.

10. A method as set forth in claim 9 wherein the color texture map is loaded onto the polygon terrain mesh to produce a color polygon terrain representation for display.

11. In an aircraft display system having a processor for processing data for displaying terrain, a method for reducing the required computational load on the processor comprising:

obtaining terrain data from a data source,

using the terrain data to construct a polygon terrain mesh, the polygon terrain mesh having error bounds that increase non-linearly from a viewing location, and

using the terrain mesh, dynamically generating terrain-tracing perspective projection lines.

12. A method as set forth in claim 11 wherein the terrain data comprises a terrain data patch having terrain location and terrain elevation data.

13. A method as set forth in claim 12 wherein the terrain data patch is used to compute a color texture map using absolute terrain elevation data.

14. A method as set forth in claim 13 wherein the terrain data patch is used to construct an error bound array for a triangle binary tree based terrain patch, and the polygon terrain mesh is constructed using the error bound array.

15. A method as set forth in claim 14 wherein the color texture map is loaded onto the polygon terrain mesh to produce a color polygon terrain representation for display.

16. In an aircraft display system having a processor for processing data for displaying terrain, a method for reducing the required computational load on the processor comprising:

obtaining terrain data from a data source,

using the terrain data to construct a polygon terrain mesh, the polygon terrain mesh having error bounds that increase non-linearly from a viewing location providing higher resolution nearer the viewing location,

computing geo-morphing parameters based on the error bound, using the parameters to control geo-morphing range and duration to ensure visually smooth transitions from lower resolution displays to higher resolution displays, and

dynamically generating terrain-tracing range rings using the geo-morphed polygon terrain mesh.

17. A method as set forth in claim 16 wherein the terrain data comprises a terrain data patch having terrain location and terrain elevation data.

18. A method as set forth in claim 17 wherein the terrain data patch is used to compute a color texture map using absolute terrain elevation data.

19. A method as set forth in claim 18 wherein the terrain data patch is used to construct an error bound array for a triangle binary tree based terrain patch, and the polygon terrain mesh is constructed using the error bound array.

20. A method as set forth in claim 19 wherein the color texture map is loaded onto the polygon terrain mesh to produce a color polygon terrain representation for display.