DETERMINING RELATIVE ELEVATION USING GPS AND RANGING

• US 20070099628A1
• Filed: 10/31/2006
• Published: 05/03/2007
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: TeraHop Networks Incorporated
• Inventors: TWITCHELL, Robert
• Granted Patent: US 7,742,772 B2
• Time in Patent Office: Days
• 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 for determining a position of a wireless communication device, the method comprising the steps of:

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

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

(c) determining a distance between the first wireless communication device and the second wireless communication device; and

(d) determining 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.

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

3. The method of claim 2, wherein the satellite navigation system is GPS.

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

5. 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.

6. 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.

7. 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 (x,y,) position.

8. The method of claim 1, 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.

9. A method for determining a position of a wireless communication device, the method comprising the steps of:

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

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

(c) determining a distance between the first wireless communication device and the second wireless communication device; and

(d) determining a (z) position of the first wireless communication device;

(e) determining a (z) position of the second wireless communication device based on,

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

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

(iii) the determined (z) position of the first wireless communication device.

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

11. The method of claim 10, wherein the satellite navigation system is GPS.

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

13. The method of claim 9, wherein the distance between the first wireless communication device and the second wireless communication device is determined using radio frequency ranging.

14. The method of claim 9, 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.

15. The method of claim 9, wherein determining the (z) position of the first wireless communication device includes determining the (z) position of the first wireless communication device relative to the ground, and wherein determining the (z) position of the second wireless communication device includes adding the (z) position of the first wireless communication system to a relative elevational differential determined between the first and second wireless communication devices.

16. The method of claim 9, wherein determining the (z) position of the first wireless communication device includes determining the (z) position of the first wireless communication device relative to sea level, and wherein determining the (z) position of the second wireless communication device includes adding the (z) position of the first wireless communication system to a relative elevational differential determined between the first and second wireless communication devices.

17. A method for determining a position of a wireless communication device, the method comprising the steps of:

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

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

(c) determining a distance between the first wireless communication device and the second wireless communication device;

(d) determining 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;

(e) determining an (x,y) position of a third wireless communication device;

(f) determining a distance between the first wireless communication device and the third wireless communication device;

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

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

(ii) the determined distance between the first and third wireless communication devices.

18. The method of claim 17, further comprising communicating the determined position of the third wireless communication device to the second wireless communication device.

19. The method of claim 17, further comprising determining a distance between the second wireless communication device and the third wireless communication device based on the determined distance between the first and second wireless communication devices and the determined distance between the first and third wireless communication devices.

20. The method of claim 17, wherein the (x,y) position of at least one of the first, second and third wireless communication devices is determined using a satellite navigation system.

21. The method of claim 20, wherein the satellite navigation system is GPS.

22. The method of claim 17, wherein the distance between the first wireless communication device and the second wireless communication device, and the distance between the first wireless communication device and the third wireless communication device, are each determined using radio frequency ranging.

23. The method of claim 17, wherein:

(i) the relative elevational differential between the first wireless communication device and the second wireless communication device is determined by calculating the square root of,

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

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

(ii) the relative elevational differential between the first wireless communication device and the third wireless communication device is determined by calculating the square root of,

(A) the square of the determined distance between the first wireless communication device and the third wireless communication device less,

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