Network aided terrestrial triangulation using stars (NATTS)

• US 7,912,644 B2
• Filed: 03/24/2009
• Issued: 03/22/2011
• Est. Priority Date: 06/03/2005
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: TeraHop Networks Incorporated
• Inventors: Twitchell, Robert W. Jr.
• Primary Examiner(s): Hellner; Mark
• Application Number:
  US12/410,324
• Publication Number:
  US 20090182504A1
• Time in Patent Office: 728 Days
• Field of Search: 701/222, 701/200
• US Class Current: 701/222
• CPC Class Codes: G01C 21/025 with the use of startrackers

Abstract

A method for determining a terrestrial location of an apparatus that is deployed in a generally known geographical region includes capturing, by the apparatus, an earthbound image of the sky from a terrestrial location at an identified time; communicating, by the apparatus, data representative of the captured earthbound image of the sky; and determining the terrestrial location of the apparatus based on the data communicated by the apparatus by comparing the captured earthbound image of the sky to a master mapping of the sky relative to the surface of the Earth.

Claims

1. A method for determining a terrestrial location of an apparatus that is located in a generally known geographical region, comprising the steps of:

(a) deploying the apparatus within the geographical region;

(b) capturing, by the apparatus, an earthbound image of the sky from a terrestrial location within the geographical region at an identified time;

(c) communicating, to a location outside of the geographical region, data representative of the earthbound image of the sky captured by the apparatus; and

(d) determining, at the location outside of the geographical region, the terrestrial location of the apparatus within the geographical region based on the communicated data by comparing the captured earthbound image of the sky to a master mapping of the sky relative to the surface of the Earth;

(e) wherein the identified time at which the earthbound image of the sky is captured is a time that is predetermined prior to deployment of the apparatus within the geographical region.

2. The method of claim 1, wherein the data representative of the captured earthbound image of the sky that is communicated includes the identified time at which the earthbound image of the sky was captured.

3. The method of claim 1, wherein earthbound images of the sky are captured by the apparatus at predetermined time intervals.

4. The method of claim 1, further comprising processing the captured earthbound image of the sky by the apparatus prior to communicating the data representative of the captured earthbound image of the sky.

5. The method of claim 4, wherein the processing comprises compensating for atmospheric distortions in the captured earthbound image of the sky.

6. The method of claim 4, wherein processing comprises sharpening of the captured earthbound image of the sky.

7. The method of claim 1, wherein the capturing of an earthbound image of the sky comprises capturing the earthbound image of the sky along a vertical skyward axis local to the terrestrial location at which the image is captured.

8. The method of claim 1, further comprising performing correction calculations for the captured earthbound image of the sky when the earthbound image of the sky is not captured along a local vertical skyward axis, whereby the data representative of the captured earthbound image of the sky corresponds to an earthbound image of the sky that is captured along a vertical skyward axis local to the terrestrial location at which the image is captured.

9. The method of claim 8, wherein the correction calculations utilize an angle measured between an axis of the captured earthbound image and the vertical skyward axis local to the terrestrial location at which the image is captured.

10. The method of claim 1, wherein the step of determining the terrestrial location of the apparatus within the geographical region based on the communicated data by comparing the captured earthbound image of the sky to a master mapping of the sky relative to the surface of the Earth includes,

(i) manipulating the master map of the sky into a model in which the shape of a sphere is disposed above the surface of the Earth;

(ii) projecting latitude and longitude lines perpendicularly from the surface of the Earth onto the master mapping of the sky;

(iii) comparing the captured earthbound image to the manipulated master mapping of the sky; and

(iv) matching the captured earthbound image to the manipulated master mapping of the sky and reading the latitude and longitude values on the manipulated master map of the sky at the point where the captured earthbound image most closely matches the manipulated master map of the sky, thereby determining the terrestrial location from which the earthbound image was captured by the deployed apparatus.

11. The method of claim 1, wherein the step of communicating data representative of the captured earthbound image of the sky comprises wirelessly communicating, by the apparatus, the data representative of the captured earthbound image of the sky.

12. The method of claim 11, wherein the wireless communications comprise cellular communications.

13. The method of claim 11, wherein the wireless communications comprise satellite communications.

14. The method of claim 1, wherein the step of communicating, to a location outside of the geographical region, data representative of the earthbound image of the sky captured by the apparatus comprises communicating the data representative of the earthbound image of the sky captured by the apparatus over the Internet.

15. The method of claim 1, wherein the step of communicating, to a location outside of the geographical region, data representative of the earthbound image of the sky captured by the apparatus comprises communicating the data representative of the earthbound image of the sky captured by the apparatus over a wide area network (WAN).

16. The method of claim 1, further comprising communicating the data representative of the captured earthbound image of the sky over a satellite communications network.

17. The method of claim 1, further comprising communicating the data representative of the captured earthbound image of the sky over a cellular communications network.

18. The method of claim 1, further comprising communicating the data representative of the captured earthbound image of the sky over the Internet.

19. The method of claim 1, further comprising communicating, to the apparatus, the determined terrestrial location of the apparatus within the geographical region.