Abstract: GNSS receivers and methods of determining a current receiver state of a GNSS receiver are provided. The method includes receiving positioning signals from a plurality of satellites; generating a plurality of correlation grids from the received positioning signals, where each correlation grid is associated with a respective one of the plurality of satellites; estimating a probability distribution of the current receiver state from the plurality of correlation grids; and determining a maximum likelihood estimate of the current receiver state from the estimated probability distribution.

Abstract: A method and apparatus for harvesting information from a plurality of radio frequency (RF) sources. In one example, a collector device receives RF signals from the RF sources to produce the harvesting information. The collector device also determines environmental context information describing a physical environment of the collector device as the RF signals were being received, and a position of the collector device where the RF signals where received. The collector device then associates the environmental context information with the harvesting information and the position, and transmits the harvesting information and position with the associated environmental context information to a server device. The server device may then compute positioning information biased to different environmental contexts. This biased positioning information may then be utilized by other collector devices having similar environmental contexts to better estimate their respective locations.

Abstract: GNSS receivers and methods of determining a current receiver state of a GNSS receiver are provided. The method includes receiving positioning signals from a plurality of satellites; generating a plurality of correlation grids from the received positioning signals, where each correlation grid is associated with a respective one of the plurality of satellites; estimating a probability distribution of the current receiver state from the plurality of correlation grids; and determining a maximum likelihood estimate of the current receiver state from the estimated probability distribution.

Abstract: A GNSS receiver design is tested, which design includes software for generating position/time related data (DPT) based on raw digital data (dRAW) when the software is executed in a processing unit of the receiver. GNSS signals (SRF) are received via a radio frequency input device while moving the radio frequency input device along a route trajectory. The received GNSS signals (SRF) are fed to a radio-frequency front end of a Representative example of a receiver unit built according to the design to be tested. The radio-frequency front end produces raw digital data (dRAW) representing the received GNSS signals (SRF), and the raw digital data (dRAW) are stored in a primary data storage as a source file (Fsc). The source file (Fsc) is read from the primary data storage, and the source file (Fsc) is processed by means of the software to generate at least one set of position/time related data (DPT).

Abstract: GNSS receivers and methods of determining a current receiver state of a GNSS receiver are provided. The method includes receiving positioning signals from a plurality of satellites; generating a plurality of correlation grids from the received positioning signals, where each correlation grid is associated with a respective one of the plurality of satellites; estimating a probability distribution of the current receiver state from the plurality of correlation grids; and determining a maximum likelihood estimate of the current receiver state from the estimated probability distribution.

Abstract: A system and method for determining locations of a plurality of radio frequency (RF) signal sources. The method includes receiving RF signals from the RF signal sources, and determining locations of the RF signal sources based on the received RF signals. The method also includes determining an anchor having an absolute location identified by map data, and then adjusting the determined locations of the RF signal sources based on the anchor.

Abstract: A system and method for switching a positioning device between using a first positioning technology and using a second positioning technology includes determining a location of the positioning device based on the first positioning technology, determining environment information corresponding to the location of the positioning device, and determining a location of a boundary where switching from the first positioning technology to the second positioning technology should occur. The method also includes switching from the first positioning technology to the second positioning technology prior to the positioning device crossing the boundary.

Abstract: A location system that employs multiple magnetic transmitters that provide magnetic fields modulated with respectively different identifying signals. A magnetic receiver extracts the identifying signal from the modulated magnetic field to determine its location. The magnetic transmitters may be configured as magnetic signal sources including magnetic pseudolites. The identifying signals are repeated at predetermined intervals such that the magnetic receiver accumulates the repeated identifying signals to provide processing gain.

Abstract: An apparatus for determining a location of a receiver by using signals received by the receiver from a number of satellites, the apparatus being configured to, when the receiver has been unable to decode a time-of-transmission from the satellite signals, determine a location for the receiver by use of an algorithm that takes an estimate of the location of the receiver as an input, and, when an estimate of the location of the receiver is unavailable, determine an approximate location of the receiver in dependence on the satellite signals and input that approximate location into the algorithm as the estimate of the location of the receiver.

Abstract: A system and method for determining locations of a plurality of radio frequency (RF) signal sources. The method includes receiving RF signals from the RF signal sources, and determining locations of the RF signal sources based on the received RF signals. The method also includes determining an anchor having an absolute location identified by map data, and then adjusting the determined locations of the RF signal sources based on the anchor.

Abstract: A method and apparatus for harvesting information from a plurality of radio frequency (RF) sources. In one example, a collector device receives RF signals from the RF sources to produce the harvesting information. The collector device also determines environmental context information describing a physical environment of the collector device as the RF signals were being received, and a position of the collector device where the RF signals where received. The collector device then associates the environmental context information with the harvesting information and the position, and transmits the harvesting information and position with the associated environmental context information to a server device. The server device may then compute positioning information biased to different environmental contexts. This biased positioning information may then be utilized by other collector devices having similar environmental contexts to better estimate their respective locations.

Abstract: A system and method for determining locations of a plurality of radio frequency (RF) signal sources. The method includes receiving RF signals from the RF signal sources, and determining locations of the RF signal sources based on the received RF signals. The method also includes determining an anchor having an absolute location identified by map data, and then adjusting the determined locations of the RF signal sources based on the anchor.

Abstract: A system and method for switching a positioning device between using a first positioning technology and using a second positioning technology includes determining a location of the positioning device based on the first positioning technology, determining environment information corresponding to the location of the positioning device, and determining a location of a boundary where switching from the first positioning technology to the second positioning technology should occur. The method also includes switching from the first positioning technology to the second positioning technology prior to the positioning device crossing the boundary.

Abstract: A system and method for determining locations of a plurality of radio frequency (RF) signal sources. The method includes receiving RF signals from the RF signal sources, and determining locations of the RF signal sources based on the received RF signals. The method also includes determining an anchor having an absolute location identified by map data, and then adjusting the determined locations of the RF signal sources based on the anchor.

Abstract: GNSS receivers and methods of determining a current receiver state of a GNSS receiver are provided. The method includes receiving positioning signals from a plurality of satellites; generating a plurality of correlation grids from the received positioning signals, where each correlation grid is associated with a respective one of the plurality of satellites; estimating a probability distribution of the current receiver state from the plurality of correlation grids; and determining a maximum likelihood estimate of the current receiver state from the estimated probability distribution.

Abstract: An apparatus for determining a location of a receiver by using signals received by the receiver from a number of satellites, the apparatus being configured to, when the receiver has been unable to decode a time-of-transmission from the satellite signals, determine a location for the receiver by use of an algorithm that takes an estimate of the location of the receiver as an input, and, when an estimate of the location of the receiver is unavailable, determine an approximate location of the receiver in dependence on the satellite signals and input that approximate location into the algorithm as the estimate of the location of the receiver.

Abstract: A GNSS receiver design is tested, which design includes software for generating position/time related data (DPT) based on raw digital data (dRAW) when the software is executed in a processing unit of the receiver. GNSS signals (SRF) are received via a radio frequency input device while moving the radio frequency input device along a route trajectory. The received GNSS signals (SRF) are fed to a radio-frequency front end of a representative example of a receiver unit built according to the design to be tested. The radio-frequency front end produces raw digital data (dRAW) representing the received GNSS signals (SRF), and the raw digital data (dRAW) are stored in a primary data storage as a source file (Fsc). The source file (Fsc) is read from the primary data storage, and the source file (Fsc) is processed by means of the software to generate at least one set of position/time related data (DPT).