Abstract: In a method for accurately estimating gait characteristics of a user, first parameters indicative of user movement, including a GNSS-derived speed and step count, are monitored. Values of the first parameters are processed to determine values of second parameters indicative of movement of the user. The processing includes using values of at least one monitored parameter to generate one or more inputs to an estimator (e.g., Kalman filter) having the second parameters as estimator states. At least two of the second parameters are collectively indicative of a mapping between step frequency and step length of the user. A graphical user interface may display values of at least one of the second parameters, and/or at least one parameter derived from one or more of the second parameters.

Abstract: Methods and systems for location determination are described herein. An example implementation may involve receiving signals from a set of satellites to determine a general location of a receiver. After receiving a signal from a satellite, the receiver may determine an angle of reception that indicates an orientation of the satellite relative to the receiver. The receiver may further obtain topography information for the general location that indicates the positions and elevations of features (e.g., buildings) at the general location. For instance, the receiver may use elevation maps or sensors to determine the topography information. Using the topography information and determined angles of receptions, the receiver may identify any signals that reflected off a feature prior to reaching the receiver. As a result, the receiver may determine and use the reflected path traveled by a reflected signal to refine the general location of the receiver.

Abstract: A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data. Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

Abstract: A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

Abstract: A method of localization using bearing from environmental features includes receiving an estimated location of a global navigation satellite system (GNSS) receiver associated with a user and a corresponding bearing for the GNSS receiver. The method also includes identifying one or more environmental features about the estimated location of the GNSS receiver. The method further includes determining whether an orientation of a respective environmental feature of the one or more environmental features correlates to the corresponding bearing for the GNSS receiver. When the orientation of the respective environmental feature correlates to the corresponding bearing for the GNSS receiver, the method includes generating an updated bearing for the GNSS receiver or locational system that matches the orientation of the respective environmental feature.

Abstract: Methods and systems for location determination are described herein. An example implementation may involve receiving signals from a set of satellites to determine a general location of a receiver. After receiving a signal from a satellite, the receiver may determine an angle of reception that indicates an orientation of the satellite relative to the receiver. The receiver may further obtain topography information for the general location that indicates the positions and elevations of features (e.g., buildings) at the general location. For instance, the receiver may use elevation maps or sensors to determine the topography information. Using the topography information and determined angles of receptions, the receiver may identify any signals that reflected off a feature prior to reaching the receiver. As a result, the receiver may determine and use the reflected path traveled by a reflected signal to refine the general location of the receiver.

Abstract: Methods and systems for location determination are described herein. An example implementation may involve receiving signals from a set of satellites to determine a general location of a receiver. After receiving a signal from a satellite, the receiver may-determine an angle of reception that indicates an orientation of the satellite relative to the receiver. The receiver may further obtain topography information for the general location that indicates the positions and elevations of features (e.g., buildings) at the general location. For instance, the receiver may use elevation maps or sensors to determine the topography information. Using the topography information and determined angles of receptions, the receiver may identify any signals that reflected off a feature prior to reaching the receiver. As a result, the receiver may determine and use the reflected path traveled by a reflected signal to refine the general location of the receiver.

Abstract: A method of Doppler-based localization includes establishing an estimated position for a moving receiver. The method also includes generating a plurality of candidate positions about the estimated position. Each candidate position corresponds to a possible actual location of the moving receiver. For each available satellite, the method includes receiving a measured Doppler effect for a signal from the respective available satellite caused by the moving receiver. For each available satellite, the method also includes, at each candidate position, determining a predicted direction of the signal based on ray-launching the signal to the respective satellite and generating a predicted Doppler effect for the moving receiver.

Abstract: A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data. Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

Abstract: A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

Abstract: A method of localization using bearing from environmental features includes receiving an estimated location of a global navigation satellite system (GNSS) receiver associated with a user and a corresponding bearing for the GNSS receiver. The method also includes identifying one or more environmental features about the estimated location of the GNSS receiver. The method further includes determining whether an orientation of a respective environmental feature of the one or more environmental features correlates to the corresponding bearing for the GNSS receiver. When the orientation of the respective environmental feature correlates to the corresponding bearing for the GNSS receiver, the method includes generating an updated bearing for the GNSS receiver or locational system that matches the orientation of the respective environmental feature.

Abstract: A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data. Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

Abstract: A method of Doppler-based localization includes establishing an estimated position for a moving receiver. The method also includes generating a plurality of candidate positions about the estimated position. Each candidate position corresponds to a possible actual location of the moving receiver. For each available satellite, the method includes receiving a measured Doppler effect for a signal from the respective available satellite caused by the moving receiver. For each available satellite, the method also includes, at each candidate position, determining a predicted direction of the signal based on ray-launching the signal to the respective satellite and generating a predicted Doppler effect for the moving receiver.

Abstract: A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data. Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

Abstract: Examples for determining velocity using a reflected positioning signal are presented herein. An example may involve a receiver receiving signals from satellites and identifying a particular signal that reflected off a reflecting plane prior to reaching the receiver. The receiver may then determine a reflected satellite position for a satellite that transmitted the particular signal. The reflected satellite position may be determined by reflecting a position of the satellite about the reflecting plane. The receiver may then determine a direction vector to the reflected satellite position for the satellite and determine its velocity using the determined direction vector.

Abstract: In a method for accurately estimating gait characteristics of a user, first parameters indicative of user movement, including a GNSS-derived speed and step count, are monitored. Values of the first parameters are processed to determine values of second parameters indicative of movement of the user. The processing includes using values of at least one monitored parameter to generate one or more inputs to an estimator (e.g., Kalman filter) having the second parameters as estimator states. At least two of the second parameters are collectively indicative of a mapping between step frequency and step length of the user. A graphical user interface may display values of at least one of the second parameters, and/or at least one parameter derived from one or more of the second parameters.

Abstract: Examples for enhancing sensitivity to reflected GNSS signals are presented herein. An example may involve identifying, by a receiver, a particular positioning signal that reflected off a reflecting plane prior to reaching the receiver. The receiver may be in motion. The example may also involve determining a reflected satellite position for a satellite that transmitted the particular positioning signal based on identifying the particular positioning signal. The reflected satellite position may be determined by reflecting a position of the satellite about the reflecting plane. The example may also involve determining a direction vector to the reflected satellite position for the satellite and performing coherent integration over a threshold duration of time to increase a signal to noise ratio for the particular positioning signal based on the direction vector to the reflected satellite position.

Abstract: In a method for accurately estimating gait characteristics of a user, first parameters indicative of user movement, including a GNSS-derived speed and step count, are monitored. Values of the first parameters are processed to determine values of second parameters indicative of movement of the user. The processing includes using values of at least one monitored parameter to generate one or more inputs to an estimator (e.g., Kalman filter) having the second parameters as estimator states. At least two of the second parameters are collectively indicative of a mapping between step frequency and step length of the user. A graphical user interface may display values of at least one of the second parameters, and/or at least one parameter derived from one or more of the second parameters.

Abstract: In a method for accurately estimating gait characteristics of a user, first parameters indicative of user movement, including a GNSS-derived speed and step count, are monitored. Values of the first parameters are processed to determine values of second parameters indicative of movement of the user. The processing includes using values of at least one monitored parameter to generate one or more inputs to an estimator (e.g., Kalman filter) having the second parameters as estimator states. At least two of the second parameters are collectively indicative of a mapping between step frequency and step length of the user. A graphical user interface may display values of at least one of the second parameters, and/or at least one parameter derived from one or more of the second parameters.

Abstract: A method and apparatus for creating and distributing satellite tracking data in a compact format to a remote receiver. At least a portion of the satellite tracking data is extracted from memory and is formatted into a compact format. The compact formatted data is transmitted to the remote receiver via a distribution network.