Abstract: A method of reducing tropospheric effects in GNSS positioning includes determining a tropospheric delay by: determining zenith delays for geographical areas along a path of GNSS signal travel between a GNSS satellite and the first location of the electronic device, the zenith delays determined using current weather information of the geographical areas, the geographical areas traversed by the path represented by cells of a grid, the cells comprising a selected size; determining path delays for the geographical areas by adjusting the zenith delays based on an angle of the GNSS satellite relative to the electronic device; and summing the path delays to determine the tropospheric delay.

Abstract: A method of reducing tropospheric effects in GNSS positioning includes determining a tropospheric delay by: determining zenith delays for geographical areas along a path of GNSS signal travel between a GNSS satellite and the first location of the electronic device, the zenith delays determined using current weather information of the geographical areas, the geographical areas traversed by the path represented by cells of a grid, the cells comprising a selected size; determining path delays for the geographical areas by adjusting the zenith delays based on an angle of the GNSS satellite relative to the electronic device; and summing the path delays to determine the tropospheric delay.

Abstract: A method of calibrating output of an absolute atmospheric pressure sensor of an electronic device includes: determining, at a processor of the electronic device, that a location of the electronic device is at a known absolute altitude and outdoors; receiving, at the processor, a measured pressure from the absolute atmospheric pressure sensor; calculating, at the processor, a difference between the measured pressure and a reference pressure, the reference pressure determined by adjusting a mean sea level pressure based on the known absolute altitude relative to mean sea level at the location of the electronic device; storing the difference, in a memory of the electronic device; and applying the difference to the output of the absolute atmospheric pressure sensor; wherein determination that the electronic device is at the known absolute altitude and outdoors occurs without user input.

Abstract: A method of determining a position of a GNSS receiver includes: receiving, at the GNSS receiver, information from at least two GNSS satellites and an estimated location area from a non-GNSS positioning application, determining candidate pseudoranges corresponding to candidate correlation peaks determined based on the information received from the at least two GNSS satellites; determining possible positions of the GNSS receiver using the candidate pseudoranges and the estimated location area; determining a best possible position of the GNSS receiver from the possible positions; and setting the best possible position as the position of the GNSS receiver; wherein when multiple candidate correlation peaks corresponding to one of the at least two GNSS satellites are determined, the estimated location area is usable to reduce the number of candidate correlation peaks prior to candidate pseudoranges being determined.

Abstract: A method of determining locations of radio beacons includes: self-locating and automatically orienting electronic device hubs, determining angles of arrival of radio beacon signals at the electronic device hubs using received signal strength of radio beacons, refining received signal strength based on angle of arrival of the radio beacon signals, determining range using the refined received signal strength and antenna orientation based propagation loss models that compensate for obstacles in a deployment environment and, combining angles of arrival and ranges determined at the electronic device hubs at one of the electronic device hubs and determining locations of radio beacons within a predetermined acceptable accuracy, wherein the electronic hub devices function as receiving devices and radio beacons and radio beacon signals from a subset of the radio beacons are received at more than one electronic hub device.

Abstract: A method of determining locations of radio beacons includes: self-locating and automatically orienting electronic device hubs, determining angles of arrival of radio beacon signals at the electronic device hubs using received signal strength of radio beacons, refining received signal strength based on angle of arrival of the radio beacon signals, determining range using the refined received signal strength and antenna orientation based propagation loss models that compensate for obstacles in a deployment environment and, combining angles of arrival and ranges determined at the electronic device hubs at one of the electronic device hubs and determining locations of radio beacons within a predetermined acceptable accuracy, wherein the electronic hub devices function as receiving devices and radio beacons and radio beacon signals from a subset of the radio beacons are received at more than one electronic hub device.

Abstract: A location determining device and method of detecting GNSS signals, the method includes: determining candidate GNSS satellites orbiting above the location determining device using an estimated location area, time and predicted orbit data of all GNSS satellites and for the candidate GNSS satellites, determining nominal Dopplers by projecting velocities of the candidate GNSS satellites onto the estimated location area; determining correlation search spaces around the respective nominal Dopplers over estimated code phases; determining correlators for the correlation search spaces and performing correlation; determining receiver clock bias when correlation peaks associated with a majority of GNSS satellites are located at a common Doppler offset; detecting GNSS signals within the common Doppler offset using a set of detectors, one of the set of detectors detecting a correlation peak having a highest probability of detection; and determining a reduced search space in which GNSS signals may be detected.

Abstract: Methods and systems for compensating for gyroscopic errors. A system uses magnetometers to detect and measure a magnetic field local to a personal navigation device. When the local magnetic field is quasi-static, the rate of change of the magnetic field is combined with the rotational rate of change of the device. This generates an estimated gyroscope error. The error can then be used to correct for time-varying inherent gyroscope errors.

Abstract: A method of determining a position of a GNSS receiver includes: receiving, at the GNSS receiver, information from at least two GNSS satellites and an estimated location area from a non-GNSS positioning application, determining candidate pseudoranges corresponding to candidate correlation peaks determined based on the information received from the at least two GNSS satellites; determining possible positions of the GNSS receiver using the candidate pseudoranges and the estimated location area; determining a best possible position of the GNSS receiver from the possible positions; and setting the best possible position as the position of the GNSS receiver; wherein when multiple candidate correlation peaks corresponding to one of the at least two GNSS satellites are determined, the estimated location area is usable to reduce the number of candidate correlation peaks prior to candidate pseudoranges being determined.

Abstract: Methods and systems for compensating for gyroscopic errors. A system uses magnetometers to detect and measure a magnetic field local to a personal navigation device. When the local magnetic field is quasi-static, the rate of change of the magnetic field is combined with the rotational rate of change of the device. This generates an estimated gyroscope error. The error can then be used to correct for time-varying inherent gyroscope errors.

Abstract: A method of determining a position of a GNSS receiver includes: receiving, at the GNSS receiver, information from at least two GNSS satellites and an estimated location area from a non-GNSS positioning application, determining candidate pseudoranges corresponding to candidate correlation peaks determined based on the information received from the at least two GNSS satellites; determining possible positions of the GNSS receiver using the candidate pseudoranges and the estimated location area; determining a best possible position of the GNSS receiver from the possible positions; and setting the best possible position as the position of the GNSS receiver; wherein when multiple candidate correlation peaks corresponding to one of the at least two GNSS satellites are determined, the estimated location area is usable to reduce the number of candidate correlation peaks prior to candidate pseudoranges being determined.