METHODS, DEVICES, AND USES FOR CALCULATING A POSITION USING A GLOBAL NAVIGATION SATELLITE SYSTEM

• US 20130285849A1
• Filed: 12/22/2011
• Published: 10/31/2013
• Est. Priority Date: 12/23/2010
• Status: Active Grant

• Current Assignee: Ariel-University Research And Development Company Ltd.
• Original Assignee: Ariel-University Research And Development Company Ltd.
• Inventors: Ben-Moshe, Boaz, Levi, Harel
• Granted Patent: US 9,448,307 B2
• Time in Patent Office: Days
• US Class Current: 342/357.23
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/27 creating, predicting or correcting ephemeris or almanac data within the receiver
• CPC Class Codes: G01S 19/31 Acquisition or tracking of other signals for positioning
• CPC Class Codes: G01S 19/39 the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 19/50 whereby the position solution is constrained to lie upon a particular curve or surface, e.g. for locomotives on railway tracks

Abstract

The invention, in some embodiments, relates to the field of global navigation satellite systems, and more particularly to the field of methods and devices for improving accuracy of position determination by receivers of global navigation satellite systems. Some embodiments of the invention relate to methods for generating a three-dimensional (3-D) representation of an urban area by a receiver of a global navigation satellite system using blocked lines of sight to satellites of the system. Additional embodiments of the invention relate to methods for transmitting a three-dimensional (3-D) representation of an urban area by a receiver of a global navigation satellite system for improving calculation of location by the global navigation satellite system receiver.

Claims

1. A method for calculating the position of a GNSS (Global Navigation Satellite System) receiver, comprising:

receiving a plurality of signals from a first plurality of GNSS satellites;

calculating a region in which a GNSS receiver is located based on at least some of said received signals;

for each satellite in a second plurality of GNSS satellites, classifying whether;

said satellite is a line-of-sight (LOS) satellite, having a line of sight to said GNSS receiver;

or

said satellite is a non-line-of-sight (NLOS) satellite, not having a line of sight to said GNSS receiver;

obtaining at least one three-dimensional representation of an area including said region;

for each satellite in said second plurality of GNSS satellites, using said at least one three-dimensional representation to define a three-dimensional shading representation including at least one illuminated subregion and at least one shaded subregion, such that a GNSS receiver located in said at least one illuminated subregion has a line of sight said satellite and a GNSS receiver located in said at least one shaded subregion does not have a line of sight to said satellite;

for each said three-dimensional shading representation defining a shading surface which divides between said at least one illuminated subregion and said at least one shaded subregion, such that said at least one illuminated subregion is located above said shading surface and said at least one shaded subregion is located beneath said shading surface; and

for each satellite in said second plurality of GNSS satellites, eliminating from said region at least one subregion, thereby to identify a position in which said GNSS receiver is located, wherein;

if said satellite is a LOS satellite, eliminating from said region any portion which is located beneath said shading surface defined for said satellite; and

if said satellite is a NLOS satellite, eliminating from said region any portion which is located above said shading surface defined for said satellite.

7. A method according to claim 1, also comprising, following said calculating and prior to said classifying, testing whether a radius of said region is greater than a predetermined threshold.

13. A method according to claim 1, wherein at least one of said defining a three-dimensional shading representation and said defining a shading surface is carried out substantially in real time.

14. A method according to claim 13 and wherein said defining is by said GNNS receiver.

15. A method according to claim 13 and wherein at least one of said defining a three-dimensional shading representation and said defining a shading surface is carried out by a server, external to said GNSS receiver, and at least one of said three-dimensional shading representation and said shading surface is loaded from said server into said GNSS receiver using at least one wireless communication method.

16. A method according to claim 1, wherein at least one of said defining a three-dimensional shading representation and said defining a shading surface is in advance of said classification of said second plurality of GNSS satellites, in a device external to said GNSS receiver.

18. A method according to claim 1, wherein at least one of said defining a three-dimensional shading representation and said defining a shading surface comprises recalculating at least one of said three-dimensional shading representation and said shading surface at a rate not slower than every 30 seconds based on changes to ephemeris data of said satellite.

19. A method according to claim 1, wherein said defining a three-dimensional shading representation includes defining at least one border subregion to lay along said shading surface corresponding to said three-dimensional shading representation.

21. A method according to claim 1, wherein said eliminating comprises:

defining a set of surface inequalities, each corresponding to a constraint defined by one of said shading surfaces; and

finding a solution to said set of surface inequalities, which solution comprises said identifying said position.

24. A method according to claim 21 and wherein said finding a solution comprises:

assigning a confidence value to each inequality in said set of surface inequalities; and

finding a solution which maximizes the confidence of satisfied surface inequalities of said set of surface inequalities.

2-6. -6. (canceled)

8-12. -12. (canceled)

17. (canceled)

20. (canceled)

22-23. -23. (canceled)

25. A device for calculating the position of a GNSS (Global Navigation Satellite System) receiver, comprising:

a signal receiver configured to receive a plurality of signals from a first plurality of GNSS satellites;

a region-calculating module configured to calculate a region in which a GNSS receiver is located based on at least some of said received signals;

a satellite classification module, configured to, for each satellite in a second plurality of GNSS satellites, classify whether;

said satellite is a line-of-sight (LOS) satellite, having a line of sight to said GNSS receiver;

or

said satellite is a non-line-of-sight (NLOS) satellite, not having a line of sight to said GNSS receiver;

a shading representation defining module configured to obtain at least one three-dimensional representation of an area including said region and, for each satellite in said second plurality of GNSS satellites, to use said at least one three-dimensional representation to define a three-dimensional shading representation including at least one illuminated subregion and at least one shaded subregion, such that a GNSS receiver located in said at least one illuminated subregion has a line of sight said satellite and a GNSS receiver located in said at least one shaded subregion does not have a line of sight to said satellite;

a shading surface calculating module configured to define, for each three-dimensional shading representation, a shading surface which divides between said at least one illuminated subregion and said at least one shaded subregion, such that said at least one illuminated subregion is located above said shading surface and said at least one shaded subregion is located beneath said shading surface; and

a subregion eliminating module configured, for each satellite in said second plurality of GNSS satellites, to eliminate from said region at least one subregion, thereby to identify a position in which said GNSS receiver is located, wherein;

if said satellite is a LOS satellite, eliminating from said region any portion which is located beneath said shading surface defined for said satellite; and

if said satellite is a NLOS satellite, eliminating from said region any portion which is located above said shading surface defined for said satellite.

37. A device according to claim 25, wherein at least one of said three-dimensional shading representation and said shading surface is defined substantially in real time.

38. A device according to claim 37 and wherein said shading representation defining module is configured to define said at least one of said three-dimensional shading representation and said shading surface.

39. A device according to claim 37 and also comprising a server, external to said GNSS receiver, said server being configured to define said at least one of said three-dimensional shading representation and said shading surface and to load said at least one of said three-dimensional shading representation and said shading surface into said GNSS receiver using at least one wireless communication method.

40. A device according to claim 25, also comprising a shading defining device external to said GNSS receiver, configured to define at least one of said three-dimensional shading representation and said shading surface in advance of said classification of said second plurality of GNSS satellites.

42. A device according to claim 25, wherein shading representation defining module is configured to recalculate at least one of said three-dimensional shading representation and said shading surface at a rate not slower than every 30 seconds based on changes to ephemeris data of said satellite.

43. A device according to claim 25, wherein said shading representation defining module is also configured to define at least one border subregion which lies along said shading surface corresponding to said three-dimensional shading representation.

45. A device according to claim 25, wherein said subregion eliminating module comprises:

an inequality defining module configured to define a set of surface inequalities, each corresponding to a constraint defined by one of said shading surfaces; and

a solution finding module configured to find a solution to said set of surface inequalities, which solution comprises said identifying said position.

48. A device according to claim 45 and wherein said solution finding module is configured to find a solution by assigning a confidence value to each inequality in said set of surface inequalities and finding a solution which maximizes the confidence of satisfied surface inequalities of said set of surface inequalities.

26-36. -36. (canceled)

41. (canceled)

44. (canceled)

46-47. -47. (canceled)

49. A method for creating a three-dimensional representation of terrestrial objects in an urban area, comprising:

obtaining a log file from at least one GNSS receiver, said log file containing information obtained in an urban area;

extracting from said log file a plurality data items, each data item including a timestamp, a position, and a signal strength captured from a GNSS satellite at said position and at said timestamp;

for each of said plurality of data items, classifying whether at said timestamp and at said position;

said satellite is a line-of-sight (LOS) satellite, having a line of sight to said GNSS receiver;

or

said satellite is a non-line-of-sight (NLOS) satellite, not having a line of sight to said GNSS receiver; and

using said classification to identify three-dimensional contours of terrestrial objects in said urban area.

50-83. -83. (canceled)