Stellar-landscape/horizon image navigation

Patent metadata

Field	Value
Publication number	US-11237003-B2
Application number	US-202016890140-A
Country	US
Kind code	B2
Filing date	Jun 2, 2020
Priority date	Feb 17, 2017
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

An image-based navigation system is arranged to obtain a terrain image of a target terrain from one or more image sensors at a low altitude imaging location. The terrain image includes at least one celestial image feature and at least one terrain feature. Map database information stored in at least one hardware memory device is accessed and compared to the at least one celestial image feature and the at least one terrain feature in the terrain image to determine absolute location coordinates of the imaging location.

First claim

What is claimed is:

1. An image-based navigation system comprising:
at least one hardware processor; and
at least one hardware memory device operatively connected to the at least one hardware processor;
wherein the at least one hardware processor is configured to execute program instructions for:
obtaining a terrain image of a target terrain from one or more image sensors at a low altitude imaging location, wherein the terrain image includes at least one celestial image feature and at least one terrain feature;
accessing map database information stored in the at least one hardware memory device; and
comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information to determine absolute location coordinates of the imaging location, wherein comparing includes determining one or more lines of sight from the one or more image sensors to either one of (a) the at least one celestial image feature or (b) the at least one terrain feature, and identifying the other one of (a) the at least one celestial image feature or (b) the at least one terrain feature in a background portion of the terrain image along the one or more lines of sight.

2. The system according to claim 1 , wherein the map database information includes terrain elevation model information characterizing elevation features associated with the target terrain.

3. The system according to claim 1 , wherein the at least one terrain feature includes at least one distinctive landmark feature present in the terrain image.

4. The system according to claim 3 , wherein comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information includes determining the one or more lines of sight from the one or more image sensors to the at least one distinctive landmark feature and identifying the at least one celestial image feature present in a background portion of the terrain image along the one or more lines of sight.

5. The system according to claim 1 , wherein the at least one terrain feature includes at least one terrain horizon feature present in the terrain image.

6. The system according to claim 5 , wherein comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information includes determining the one or more lines of sight from the one or more image sensors to the at least one celestial image feature and identifying the at least one terrain horizon feature present in a background portion of the terrain image along the one or more lines of sight.

7. A computer-implemented method employing at least one hardware implemented computer processor for probabilistic landmark navigation, the method comprising:
operating the at least one hardware processor to execute program instructions for:
obtaining a terrain image of a target terrain from one or more image sensors at a low altitude imaging location, wherein the terrain image includes at least one celestial image feature and at least one terrain feature;
accessing map database information stored in at least one hardware memory device;
comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information to determine absolute location coordinates of the imaging location, wherein comparing includes determining one or more lines of sight from the one or more image sensors to either one of (a) the at least one celestial image feature or (b) the at least one terrain feature, and identifying the other one of (a) the at least one celestial image feature or (b) the at least one terrain feature in a background portion of the terrain image along the one or more lines of sight.

8. The method according to claim 7 , wherein the map database information includes terrain elevation model information characterizing elevation features associated with the target terrain.

9. The method according to claim 7 , wherein the at least one terrain feature includes at least one distinctive landmark feature present in the terrain image.

10. The method according to claim 9 , wherein comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information includes determining the one or more lines of sight from the one or more image sensors to the at least one distinctive landmark feature and identifying the at least one celestial image feature present in a background portion of the terrain image along the one or more lines of sight.

11. The method according to claim 7 , wherein the at least one terrain feature includes at least one terrain horizon feature present in the terrain image.

12. The method according to claim 11 , wherein comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information includes determining the one or more lines of sight from the one or more image sensors to the at least one celestial image feature and identifying the at least one terrain horizon feature present in a background portion of the terrain image along the one or more lines of sight.

13. A computer program product encoded in a non-transitory computer-readable medium, which when executed by a computer causes the computer to perform the following operations:
obtaining a terrain image of a target terrain from one or more image sensors at a low altitude imaging location, wherein the terrain image includes at least one celestial image feature and at least one terrain feature;
accessing map database information stored in at least one hardware memory device;
comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information to determine absolute location coordinates of the imaging location, wherein comparing includes determining one or more lines of sight from the one or more image sensors to either one of (a) the at least one celestial image feature or (b) the at least one terrain feature, and identifying the other one of (a) the at least one celestial image feature or (b) the at least one terrain feature in a background portion of the terrain image along the one or more lines of sight.

14. The product according to claim 13 , wherein the map database information includes terrain elevation model information characterizing elevation features associated with the target terrain.

15. The product according to claim 13 , wherein the at least one terrain feature includes at least one distinctive landmark feature present in the terrain image.

16. The product according to claim 15 , wherein comparing the at least one celestial image feature in the terrain image to the map database information includes determining the one or more lines of sight from the one or more image sensors to the at least one distinctive landmark feature and identifying the at least one celestial image feature present in a background portion of the terrain image along the one or more lines of sight.

17. The product according to claim 13 , wherein the at least one terrain feature includes at least one terrain horizon feature present in the terrain image.

18. The product according to claim 17 , wherein comparing the at least one celestial image feature and the at least one terrain feature in the terrain image to the map database information includes determining the one or more lines of sight from the one or more image sensors to the at least one celestial ima

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Laine Juha-Pekka J
• Blasche Gregory P
• Lane Benjamin F
• Meiser Daniel M
• Hoke Eric T
• Jamula Matthew T
• Dawson Robin M A
• Smith Stephen P

Classifications

• G06V20/13 Primary

  Satellite images · CPC title

• G01C21/20 Primary

  Instruments for performing navigational calculations (G01C21/24, G01C21/26 take precedence) · CPC title

• G06T2207/30252

  Vehicle exterior; Vicinity of vehicle · CPC title

• G01C21/02

  by astronomical means (G01C21/24, G01C21/26 take precedence) · CPC title

• G06T7/74

  involving reference images or patches · CPC title