Indoor altitude measurement by GNSS receiver

• US 9,000,977 B2
• Filed: 10/19/2011
• Issued: 04/07/2015
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: Daniel A. Katz
• Original Assignee: Daniel A. Katz
• Inventors: Katz, Daniel A.
• Primary Examiner(s): Phan, Dao
• Application Number:
  US13/276,378
• Publication Number:
  US 20130099962A1
• Time in Patent Office: 1,266 Days
• Field of Search: 342/357.28, 342/357.4, 342/357.48, 342/386, 342/458, 342/462, 342/465, 701/468, 701/470
• US Class Current: 342/357.48
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type

Abstract

Global Navigation Satellite Systems (GNSS), such as the US GPS, the European GALILEO and the Russian GLONASS are very limited indoors, due to very low power levels and significant multipath. So, though hundreds of millions of people around the world use GPS receivers, particularly embedded in mobile devices, they cannot use these devices indoors, where they stay most of the time. Present art methods for augmenting or assisting GPS indoors, are mainly based on cellular or WLAN networks, and embedded sensors such as accelerometers and compasses, yet no integrated solution was launched. The present invention discloses a method that may contribute to GNSS indoors navigation, enabling a GNSS receiver to measure its elevation above sea level, indoors, to a floor resolution. The disclosed method is based on terrestrial infrastructure, yet possibly only one beacon per building.

Claims

1. A method for determining the elevation of a receiver from a reference plane, configuring a beacon to broadcast signals detectable by said receiver, at least one of said signals specifying its transmission time instant and a reference point, said point reporting an imaginary position of said beacon, said point and said beacon substantially on a line perpendicular to said plane, and said transmission time instant accounting for the distance between said point and said beacon.

2. A method according to claim 1, said line substantially crossing the center of the earth and configuring said receiver to determine its altitude above mean sea level.

3. A method according to claim 1, wherein said receiver is configured to detect Global Navigation Satellite System (GNSS) signals or substantially alike.

4. A method according to claim 1, configuring said signals to propagate through cable, at least part of the way between said beacon and said receiver.

5. A method according to claim 4, configuring said cable with antennas or leaky antennas.

6. A method according to claim 4, configuring the transmission time instant of said at least one of said signals accounting also for propagation time on said cable.

7. A receiver for determining the elevation from a reference plane, configured to detect signals transmitted by a beacon, at least one of said signals configured to specify its transmission time instant and a reference point, said point reporting an imaginary position of the beacon, said point and said beacon on a line substantially perpendicular to said plane, and said transmission time instant accounting for the distance between said point and said beacon.

8. A receiver according to claim 7, said line substantially crossing the center of the earth and said receiver configured to determine its altitude above mean sea level.

9. A receiver according to claim 7, configured to detect Global Navigation Satellite System (GNSS) signals or substantially alike.

10. A receiver according to claim 7, said at least one of said signals configured to propagate through cable, at least part of the way between said beacon and said receiver.

11. A receiver according to claim 10, said cable configured with antennas or leaky antennas.

12. A receiver according to claim 10, the transmission time instant of said at least one of said signals configured accounting also for propagation time on said cable.

13. A receiver according to claim 7, said beacon configured to broadcast signals in elevator shaft.

14. A beacon for determining the elevation of a receiver from a reference plane, said beacon configured to broadcast signals detectable by said receiver, at least one of said signals configured to specify its transmission time instant and a reference point, said point reporting an imaginary position of the beacon, said point and said beacon on a line substantially perpendicular to said plane, and said transmission time instant accounting for the distance between said point and said beacon.

15. A beacon according to claim 14, said line substantially crossing the center of the earth and said signals configured enabling said receiver to determine its elevation above mean sea level.

16. A beacon according to claim 14, said at least one of said signals substantially emulating a signal broadcast by a Global Navigation Satellite System (GNSS).

17. A beacon according to claim 14, said signals configured to propagate through cable, at least part of the way between said beacon and said receiver.

18. A beacon according to claim 17, said cable configured with antennas or leaky antennas.

19. A beacon according to claim 17, the transmission time instant of said at least one of said signals configured accounting also for propagation time on said cable.

20. A beacon according to claim 14, coupled to a source providing accurate timing signals, at least one of:

a GNSS receiver, a cellular or mobile network or base station, a Local Area Network (LAN) or Access Point (AP), a wireless LAN or AP.