Using GPS and ranging to determine relative elevation of an asset

• US 7,742,773 B2
• Filed: 10/31/2006
• Issued: 06/22/2010
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: TeraHop Networks Incorporated
• Inventors: Twitchell, Jr., Robert W.
• Primary Examiner(s): Perez-Gutierrez, Rafael
• Assistant Examiner(s): NOBILE, DANIEL A
• Application Number:
  US11/555,173
• Publication Number:
  US 20070099629A1
• Time in Patent Office: 1,330 Days
• Field of Search: 455/456.1
• US Class Current: 455/456.1
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 19/17 Emergency applications
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/48 by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system
• CPC Class Codes: G01S 19/51 Relative positioning

Abstract

A system and method are disclosed for determining a position of a wireless communication device. A method includes determining a respective (x,y) position of two wireless communication devices, determining a distance between the two wireless communication devices, and determining a relative elevational differential between the two wireless communication devices. The relative elevational differential is determined based on the determined (x,y) positions of the two wireless communication devices and the determined distance between the first and second wireless communication devices. The (x,y) positions may be determined using GPS receivers incorporated in the wireless communication devices. Determining the distance between the devices may be accomplished using RF ranging. The relative elevational differential may be derived using the Pythagorean theorem.

Claims

1. A method of determining the floor of a building, on which a first person carrying a first wireless communication device is located, using a second wireless communication device, the method comprising the steps of:

(a) determining, utilizing electronics of a first wireless communication device, an (x,y) position of the first wireless communication device;

(b) determining, utilizing electronics of a second wireless communication device, an (x,y) position of the second wireless communication device;

(c) determining, utilizing electronics of the first wireless communication device or electronics of the second wireless communication device, a distance between the first wireless communication device and the second wireless communication device;

(d) communicating, from the second wireless communication device to the first wireless communication device, the determined (x,y) position of the second wireless communication device; and

(e) determining, utilizing electronics of the first wireless communication device, a relative elevational differential between the first wireless communication device and the second wireless communication device based on,

(i) the determined (x,y) positions of the first and second wireless communication devices, and

(ii) the determined distance between the first and second wireless communication devices;

(f) determining a number of floors corresponding to the relative elevational differential between the first wireless communication device and the second wireless communication device;

(g) wherein the determined relative elevational differential is an absolute magnitude, the method further comprising the step of determining, separately from the determination of the relative elevational differential, the direction, relative to the first wireless communication device, in which the determined relative elevational differential is to be applied.

2. The method of claim 1, wherein the first person is a first responder.

3. The method of claim 1, wherein the first person is a firefighter.

4. The method of claim 1, wherein the first person is a serviceperson.

5. The method of claim 1, further comprising the step of determining a relative elevational differential between the second wireless communication device and a floor of the building on which a second person, carrying the second wireless communication device, is located.

6. The method of claim 5, further determining the floor, of the building, on which the first person is located, on the basis of the floor on which the second person is located and the determined relative elevational differential between the first wireless communication device and the second wireless communication device.

7. The method of claim 1, wherein the (x,y) position of the first wireless communication device is determined using a satellite navigation system.

8. The method of claim 7, wherein the satellite navigation system is GPS.

9. The method of claim 1, wherein the (x,y) position of the second wireless communication device is determined using a satellite navigation system.

10. The method of claim 1, wherein the distance between the first wireless communication device and the second wireless communication device is determined using radio frequency ranging.

11. The method of claim 1, wherein the relative elevational differential between the first wireless communication device and the second wireless communication device is determined by calculating the square root of,

(i) the square of the determined distance between the first wireless communication device and the second wireless communication device less,

(ii) the square of the distance in the X-Y plane between the first wireless communication device and the second wireless communication device.

12. The method of claim 1, wherein determining at least one of the respective steps of determining an (x,y) position of the first and second wireless devices is carried out with the assistance of network aiding to help in the determination of an (x,y) position.

13. A method of determining the location of an asset carrying a first wireless communication device relative to a second wireless communication device, the method comprising the steps of:

(a) determining, utilizing electronics of a first wireless communication device, an (x,y) position of the first wireless communication device;

(b) determining, utilizing electronics of a second wireless communication device, an (x,y) position of the second wireless communication device;

(c) determining, utilizing electronics of the first wireless communication device or electronics of the second wireless communication device, a distance between the first wireless communication device and the second wireless communication device;

(d) communicating, from the second wireless communication device to the first wireless communication device, the determined (x,y) position of the second wireless communication device; and

(e) determining, utilizing electronics of the first wireless communication device, a relative elevational differential between the first wireless communication device and the second wireless communication device based on,

(i) the determined (x,y) positions of the first and second wireless communication devices, and

(ii) the determined distance between the first and second wireless communication devices;

(f) wherein the determined relative elevational differential is an absolute magnitude, the method further comprising the step of determining, separately from the determination of the relative elevational differential, a direction, relative to the first wireless communication device, in which the determined relative elevational differential is to be applied.

14. The method of claim 13, wherein the asset is a motor vehicle.

15. The method of claim 13, wherein the asset is a motor vehicle parked on a floor of a multi-level garage.

16. The method of claim 13, wherein determining at least one of the respective steps of determining an (x,y) position of the first and second wireless devices is carried out with the assistance of network aiding to help in the determination of an (x,y) position.

17. The method of claim 13, wherein determining the direction is carried out using GPS azimuth.

18. A method of determining the floor of a building, on which a first person carrying a first wireless communication device is located, using a second wireless communication device, the method comprising the steps of:

(a) determining, utilizing electronics of a first wireless communication device, an (x,y) position of the first wireless communication device;

(b) determining, utilizing electronics of a second wireless communication device, an (x,y) position of the second wireless communication device;

(c) determining, utilizing electronics of the first wireless communication device, a distance between the first wireless communication device and the second wireless communication device;

(d) communicating, from the first wireless communication device to a third wireless communication device, the determined (x,y) position of the first wireless communication device;

(e) communicating, from the first wireless communication device to the third wireless communication device, the determined distance between the first wireless communication device and the second wireless communication device;

(f) communicating, from the second wireless communication device to the third wireless communication device, the determined (x,y) position of the second wireless communication device to the first wireless communication device; and

(g) determining, utilizing electronics of the third wireless communication device, a relative elevational differential between the first wireless communication device and the second wireless communication device based on,

(i) the determined (x,y) positions of the first and second wireless communication devices, and

(ii) the determined distance between the first and second wireless communication devices;

(h) wherein the determined relative elevational differential is an absolute magnitude, the method further comprising the step of determining, separately from the determination of the relative elevational differential, a direction, relative to the first wireless communication device, in which the determined relative elevational differential is to be applied.

19. A method of determining the location of an asset carrying a first wireless communication device relative to a second wireless communication device, the method comprising the steps of:

(a) determining, utilizing electronics of a first wireless communication device, an (x,y) position of the first wireless communication device;

(b) determining, utilizing electronics of a second wireless communication device, an (x,y) position of the second wireless communication device;

(c) determining, utilizing electronics of the first wireless communication device, a distance between the first wireless communication device and the second wireless communication device;

(d) communicating, from the first wireless communication device to a third wireless communication device, the determined (x,y) position of the first wireless communication device;

(e) communicating, from the first wireless communication device to the third wireless communication device, the determined distance between the first wireless communication device and the second wireless communication device;

(f) communicating, from the second wireless communication device to the third wireless communication device, the determined (x,y) position of the second wireless communication device to the first wireless communication device; and

(g) determining, utilizing electronics of the third wireless communication device, a relative elevational differential between the first wireless communication device and the second wireless communication device based on,

(i) the determined (x,y) positions of the first and second wireless communication devices, and

(ii) the determined distance between the first and second wireless communication devices;

(h) wherein the determined relative elevational differential is an absolute magnitude, the method further comprising the step of determining, separately from the determination of the relative elevational differential, a direction, relative to the first wireless communication device, in which the determined relative elevational differential is to be applied.