Correcting GPS through secondary sensors and signal strength

• US 8,059,027 B2
• Filed: 12/29/2008
• Issued: 11/15/2011
• Est. Priority Date: 12/29/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Novik, Lev, Khosravy, Moe
• Primary Examiner(s): Issing; Gregory C
• Application Number:
  US12/344,820
• Publication Number:
  US 20100164787A1
• Time in Patent Office: 1,051 Days
• Field of Search: 342/357.74, 342/461, 342/357.23, 342/451, 342/357.25, 342/357.4, 342/357, 342/74, 455/441
• US Class Current: 342/357.25
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS

Abstract

Systems and methods that mitigate errors in positioning systems, by employing signal strength(s) of signal sources (e.g., towers adjacent to a mobile unit.) Such mitigation system verifies whether the mobile unit receiving GPS data is in static position (e.g., not moving) or is moving (e.g., dynamic position), and evaluates accuracy of the GPS reporting (e.g., discarding GPS data in static position and trusting GPS data in dynamic position).

Claims

1. In a GPS tracking system that includes a mobile unit that is communicatively coupled to a communication network comprising a plurality of base stations providing wireless communication links to the mobile device, and wherein the mobile device is also communicatively coupled to a GPS satellite system, a computer-implemented method for verifying whether the mobile device is static and for evaluating whether to use or discard of the GPS positioning data being sent to the mobile device, the method comprising:

receiving at the mobile device GPS data which is capable of being used to determine the geographic position of the mobile device at a first point in time;

receiving at the mobile device GPS data which is capable of being used to determine the geographic position of the mobile device at a second point in time;

selecting a base station that supplies a communication signal to the mobile device;

detecting strength of the communication signal sent by the base station to the mobile device at said first point in time;

detecting strength of the communication signal sent by the base station to the mobile device at said second point in time;

comparing the signal strength between the communication signal sent by the base station to the mobile device at said first and second points of time; and

if the compared signal strength has changed beyond a predetermined threshold amount, determining that the mobile device has moved and using the GPS data to verify location of the mobile device, but if the compared signal strength has not changed beyond the predetermined threshold amount, determining that the mobile device is stationary and discarding the GPS data.

2. The computer-implemented method of claim 1, wherein the mobile device includes one or more motion detector devices, and wherein the method further comprises analyzing data provided by the one or more motion detector devices to further validate whether the mobile device is static and if so, discarding the GPS data.

3. The computer-implemented method of claim 1 wherein said communication signal detected at said first and second points of time is comprised of at least one of a cellular telephone signal, a WiFi signal, a radio frequency signal or a digital television signal.

4. The computer-implemented method of claim 1 further comprising accessing a shadow mapping and log that records GPS shadows.

5. The computer-implemented method of claim 1 further comprising accessing one or more data stores that maintain parameters affecting signal strength.

6. The computer-implemented method of claim 1 wherein the mobile device comprises a comparator component and wherein comparator component performs

comparing the signal strength between the communication signal sent by the base station to the mobile device at said first and second points of time;

and

if the compared signal strength has changed beyond a predetermined threshold amount, determining that the mobile device has moved and using the GPS data to verify location of the mobile device, but if the compared signal strength has not changed beyond the predetermined threshold amount, determining that the mobile device is stationary and discarding the GPS data.

7. The computer-implemented method of claim 1 wherein the mobile device comprises a location detection component and wherein the location detection component performs

receiving at the mobile device GPS data which determines the geographic position of the mobile device at a first point in time;

receiving at the mobile device GPS data which determines the geographic position of the mobile device at a second point in time.

8. The computer-implemented method of claim 1, wherein comparing the signal strength between the communication signal sent by the base station to the mobile device at said first and second points of time, and if the compared signal strength has changed beyond a predetermined threshold amount, determining that the mobile device has moved and using the GPS data to verify location of the mobile device, but if the compared signal strength has not changed beyond the predetermined threshold amount, determining that the mobile device is stationary and discarding the GPS data are both performed at a server of the communication network.

9. The computer-implemented method of claim 1, wherein the mobile device comprises an inference component which implements an artificial intelligence scheme to correct GPS location.

10. In a GPS tracking system that includes a mobile unit that is communicatively coupled to a communication network comprising a plurality of base stations providing wireless communication links to the mobile device, and wherein the mobile device is also communicatively coupled to a GPS satellite system, a physical storage medium containing computer-executable instruction for implementing a computer-implemented method for verifying whether the mobile device is static and for whether to use or discard accuracy of the GPS positioning data being sent to the mobile device, and wherein the computer-implemented method comprises:

receiving at the mobile device GPS data which is capable of being used to determine the geographic position of the mobile device at a first point in time;

receiving at the mobile device GPS data which is capable of being used to determine the geographic position of the mobile device at a second point in time;

selecting a base station that supplies a communication signal to the mobile device;

detecting strength of the communication signal sent by the base station to the mobile device at said first point in time;

detecting strength of the communication signal sent by the base station to the mobile device at said second point in time;

comparing the signal strength between the communication signal sent by the base station to the mobile device at said first and second points of time; and

if the compared signal strength has changed beyond a predetermined threshold amount, determining that the mobile device has moved and processing said received GPS data at the first and second points of time to locate the mobile device, but if the compared signal strength has not changed beyond the predetermined threshold amount, determining that the mobile device is stationary and discarding the GPS data.

11. The computer program product of claim 10, wherein the mobile device includes one or more motion detector devices, and wherein the method further comprises analyzing data provided by the one or more motion detector devices to further validate whether the mobile device is static and if so, discarding the GPS data.

12. The computer program product of claim 10 wherein said communication signal detected at said first and second points of time is comprised of at least one of a cellular telephone signal, a WiFi signal, a radio frequency signal or a digital television signal.

13. The computer program product of claim 10 further comprising accessing a shadow mapping and log that records GPS shadows.

14. The computer program product of claim 10 further comprising accessing one or more data stores that maintain parameters affecting signal strength.

15. The computer program product of claim 10 wherein the mobile device comprises a comparator component and wherein comparator component performs

comparing the signal strength between the communication signal sent by the base station to the mobile device at said first and second points of time;

and

if the compared signal strength has changed beyond a predetermined threshold amount, determining that the mobile device has moved and using the GPS data to verify location of the mobile device, but if the compared signal strength has not changed beyond the predetermined threshold amount, determining that the mobile device is stationary and discarding the GPS data.

16. The computer program product of claim 10 wherein the mobile device comprises a location detection component and wherein the location detection component performs receiving at the mobile device GPS data which determines the geographic position of the mobile device at a first point in time;

receiving at the mobile device GPS data which determines the geographic position of the mobile device at a second point in time.

17. The computer program product of claim 10, wherein comparing the signal strength between the communication signal sent by the base station to the mobile device at said first and second points of time, and if the compared signal strength has changed beyond a predetermined threshold amount, determining that the mobile device has moved and using the GPS data to verify location of the mobile device, but if the compared signal strength has not changed beyond the predetermined threshold amount, determining that the mobile device is stationary and discarding the GPS data are both performed at a server of the communication network.

18. The computer program product of claim 10, wherein the mobile device comprises an inference component which implements an artificial intelligence scheme to correct GPS location.

19. In a GPS tracking system that includes a mobile unit that is communicatively coupled to a communication network comprising a plurality of base stations providing wireless communication links to the mobile device, and wherein the mobile device is also communicatively coupled to a GPS satellite system, a physical storage medium containing computer-executable instruction for implementing a computer-implemented method for verifying whether the mobile device is static and for evaluating whether to use or discard of the GPS positioning data being sent to the mobile device, and wherein the computer-implemented method comprises:

receiving at the mobile device GPS data which is capable of being used to determine the geographic position of the mobile device at a first point in time;

receiving at the mobile device GPS data which is capable of being used to determine the geographic position of the mobile device at a second point in time;

selecting a base station that supplies a communication signal to the mobile device;

detecting strength of the communication signal sent by the base station to the mobile device at said first point in time;

detecting strength of the communication signal sent by the base station to the mobile device at said second point in time;

comparing the signal strength between the communication signal sent by the base station to the mobile device at said first and second points of time;

if the compared signal strength has changed beyond a predetermined threshold amount, determining that the mobile device has moved and processing said received GPS data at the first and second points of time to locate the mobile device, but if the compared signal strength has not changed beyond the predetermined threshold amount, determining that the mobile device is stationary and discarding the GPS data;

analyzing data provided by one or more motion detector devices included at the mobile device to further validate whether the mobile device is static and if so, discarding the GPS data; and

implementing an artificial intelligence scheme to correct GPS location.