Network aided terrestrial triangulation using stars (NATTS)

• US 7,542,849 B2
• Filed: 06/05/2006
• Issued: 06/02/2009
• 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:
  US11/422,306
• Publication Number:
  US 20060282217A1
• Time in Patent Office: 1,093 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 deployed in a generally known geographical region, comprising the steps of:

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

(b) communicating, by the apparatus, data representative of the captured earthbound image of the sky; and

(c) 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;

(d) wherein said determining step 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 said manipulated master mapping of the sky, and

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

2. The method of claim 1, wherein the data representative of the captured earthbound image of the sky that is communicated by the apparatus 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 said captured earthbound image of the sky 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 said 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 said 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 said capturing of the earthbound image occurs at night.

11. The method of claim 1, wherein said capturing of the earthbound image occurs in daylight.

13. The method of claim 1, wherein said step of communicating, by the apparatus, 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.

14. The method of claim 13, wherein the wireless communications comprise radio frequency communications.

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

12. A method for determining a terrestrial location of an apparatus that is deployed 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 at an identified time;

(c) communicating, by the apparatus, data representative of the captured earthbound image of the sky; and

(d) 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;

(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; and

(f) wherein said step of 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 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 said manipulated master mapping of the sky; and

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