# US 10,481,274 B2 · Methods, devices, and uses for calculating a position using a global navigation satellite system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,274 B2 - Document ID: US10481274B2 - Status: Granted - Kind: B2 - Application number: 15/245,271 - Filed: 2016-08-24 - Published: 2016-12-15 - Granted: 2019-11-19 - Earliest claimed: 2010-12-23 - Assignees: Ariel-University Research and Development Company Ltd. - Applicants: Ariel-University Research and Development Company Ltd. - Inventors: Boaz Ben-Moshe; Harel Levi - Web page: https://patentgrep.com/patent/US10481274B2 ## CPC - G01S 19/31: Acquisition or tracking of other signals for positioning - G01C 21/20: Instruments for performing navigational calculations (G01C21/24, G01C21/26 take precedence) - G01S 19/23: Testing, monitoring, correcting or calibrating of receiver elements - G01S 19/27: creating, predicting or correcting ephemeris or almanac data within the receiver - 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 - G01S 19/40: Correcting position, velocity or attitude - G01S 19/42: Determining position - G01S 19/50: whereby the position solution is constrained to lie upon a particular curve or surface, e.g. for locomotives on railway tracks - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) ## 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 ### Claim 1 A method of calculating the position of a receiver of global navigation satellite signals, the method comprising: obtaining at least one three-dimensional (3D) representation of an area containing the receiver, and a 3D shading map associated with each of a plurality of global navigation satellites; for each satellite of at least a portion of said plurality of satellites: classifying whether said satellite is a line-of-sight (LOS) satellite, having a line of sight to the receiver, or a non-line-of-sight (NLOS) satellite, not having a line of sight to the receiver; comparing said shading map to said classification; and narrowing said area containing the receiver according to said comparison, thereby calculating the position as being within said narrowed area; wherein said narrowing said area is according to a set of surface inequalities, each inequality corresponding to a constraint defined by a shading surface in said 3D map. ### Claim 2 (depends on 1) The method according to claim 1, wherein said classifying comprises using signal strength classification. ### Claim 3 (depends on 1) The method according to claim 1, wherein said 3D representation of an area is obtained repeatedly. ### Claim 4 (depends on 1) The method according to claim 1, wherein said obtaining said 3D shading map is executed by the receiver based on ephemeris data of said satellite and said 3D representation. ### Claim 5 (depends on 1) The method according to claim 1, wherein said obtaining said 3D shading map is executed by a server external to said receiver, based on ephemeris data of said satellite and said 3D representation. ### Claim 6 (depends on 1) The method according to claim 1, wherein said 3D shading map is obtained repeatedly at a rate of at least once per 30 seconds. ### Claim 7 (depends on 1) The method according to claim 1, wherein said 3D shading map comprises at least one border sub-region that is unclassified as being shaded or unshaded. ### Claim 8 A method for creating a three-dimensional representation of terrestrial objects in an urban area, comprising: by a server computer, obtaining from a receiver receiving global navigation satellite signals, a plurality of positions and a respective plurality of strengths of signals received by said receiver at each of said plurality of positions from a satellite; by said server computer, identifying among said obtained positions, based on said obtained strengths, positions at which a status of said satellite changes from a line-of-sight (LOS) satellite to a non-line-of-sight satellite (NLOS), and defining said identified positions as contour edge points; by said server computer, using said identified positions to identify three-dimensional contours of terrestrial objects in said urban area, such that two-dimensional contours of said terrestrial objects are bounded by said contour edge points; and transmitting over a wireless network, at least a portion of said three-dimensional representation of said terrestrial objects to one or more GNSS receivers. ### Claim 9 (depends on 8) The method according to claim 8, wherein said plurality of positions and said respective plurality of strengths of signals are obtained for each of a plurality of satellites, and the method comprise computing a distance function corresponding to a number of satellites for a change of said status is identified. ### Claim 10 (depends on 8) The method according to claim 8, wherein said plurality of positions and said respective plurality of strengths of signals are obtained for each of a plurality of satellites, and the method comprise computing a distance function corresponding to a number of satellites for a change of said status is identified. ### Claim 11 (depends on 10) The method according to claim 10, wherein said distance function is a weighted distance function, wherein a contribution to said weighted distance function for satellites at higher angles with respect to said receiver is greater than a contribution for satellites at lower angles with respect to said receiver. ### Claim 12 (depends on 10) The method according claim 10, wherein said defining comprises defining as said contour edge points ones of said identified positions for which said distance function is greater than a predetermined threshold. ### Claim 13 (depends on 10) The method according to claim 10, comprising: for each of said plurality positions, defining a three-dimensional vector between said position and a position of said satellite based on ephemeris data of said satellite at said timestamp; labeling each vector as a LOS vector or a NLOS vector satellite, based on a status of said satellite; and defining the height of said three-dimensional contours to satisfy at least some of a plurality of constraints based on said plurality of three-dimensional vectors, wherein said height of said three-dimensional contours is defined to obstruct some of said three-dimensional vectors labeled as NLOS vectors, and not to obstruct some others of said three-dimensional vectors labeled as LOS vectors. ### Claim 14 A method for transmitting a three-dimensional representation of an area, to a GNSS receiver, for improving calculation, comprising: at a fixed location, calculating by a server computer a shading three-dimensional representation of an area at a first rate; over a wireless network, receiving, by said server computer at said fixed location, from a GNSS receiver an indication of a location of the GNSS receiver, said location being included in said area; and transmitting over said wireless network a portion of said shading three-dimensional representation corresponding to a portion of said area from said server computer at said fixed location to said GNSS receiver at a second rate, wherein said portion of said area contains said received location, and said portion of said shading three-dimensional representation includes a three-dimensional representation of said received location. ### Claim 15 (depends on 14) The method according to claim 14, wherein said calculating comprises repeatedly calculating said shading three-dimensional representation of said area, at least once every 24 hours. ### Claim 16 (depends on 14) The method according to claim 14, further comprising selecting said second rate based on a processing power of said GNSS receiver. ### Claim 17 (depends on 14) The method according to claim 14, further comprising selecting said second rate based on a transmission bandwidth.