Abstract: One or more processors obtain GNSS receiver data captured during a time period by a GNSS receiver disposed onboard a constrained vehicle traversing a constrained route. The processor(s) determine a GNSS-based position estimate based on the GNSS receiver data. The position estimate indicates an estimated location of the GNSS receiver during at least a portion of the time period. The processor(s) determine an error characterization corresponding to an offset between the position estimate and an expected location of the GNSS receiver along the constrained route. The processor(s) cause a mobile device to perform a positioning or navigation-related function that accounts for the error characterization.

Abstract: An apparatus obtains instances of positioning quality information comprising respective position estimates, respective positioning approach indicators, and respective characteristics of the respective position estimates. The apparatus partitions the instances of positioning quality information into a plurality of groups, where each group corresponds to a geographic area, and partitions the instances of each group into clusters corresponding to positioning approaches. For each respective cluster of each respective group, the apparatus determines a respective positioning index based at least in part on respective characteristics of the respective instances of positioning quality information assigned to the respective cluster. The apparatus provides at least one instance of positioning index information, such that performance of a positioning and/or navigation-related function for a mobile apparatus may be controlled at least in part by the instance of positioning index information.

Abstract: A method, apparatus and computer program product facilitate corrections to be made to a location determined utilizing a satellite-based positioning technique to reduce the errors introduced by atmospheric delay and/or advance of navigation signals propagating through an atmospheric layer, such as the ionosphere. In the context of a method for enabling a customized request for corrections to be made, the method includes determining a perimeter of a grid within which the corrections are sought and transmitting, toward a service provider, a request that identifies one or more correction points within the perimeter of the grid. In response to the request, the method includes receiving information associated with the corrections. The method also includes determining a position based upon the satellite-based positioning technique in combination with the received information associated with the corrections.

Abstract: A method, apparatus and computer program product monitor the quality of correction data. In a method, first parameter(s) associated with a navigation satellite or propagation of signals transmitted by the navigation satellite are predicted based upon prior data including prior correction data associated with the navigation satellite or the propagation of signals transmitted thereby. The method derives second parameter(s) associated with the navigation satellite or the propagation of signals transmitted thereby based upon second data including second correction data associated with the navigation satellite or the propagation of signals transmitted thereby. The second data including the second correction data is more recent than the prior data including the prior correction data. The method compares the first parameter(s) to the second parameter(s) and, based on the comparing, generates or provides information regarding the quality of the correction data.

Abstract: A method, apparatus and computer program product determine a position of a client computing device. In the context of a method, a parameter, such as an orbit or a clock, associated with a respective navigation satellite are predicted, with the client computing device, based on data associated with the respective navigation satellite. The method also includes providing time information to a correction service identifying the data used as a basis for predicting the parameter associated with the respective navigation satellite. The method further includes receiving, from the correction service, a correction to the parameter that has been predicted for the respective navigation satellite and determining the position of the client computing device based upon the parameter that has been predicted for the respective navigation satellite in combination with the correction thereto.

Abstract: A method, apparatus and computer program product are provided for detecting multipath signals from a navigation satellite. In the context of a method, the method includes obtaining a measurement of a parameter based on signals transmitted by the navigation satellite and received by a navigation device and determining an estimated position of the navigation device upon receiving the signals. Based on navigation data regarding a position of the navigation satellite and correction data regarding a correction to the position of the navigation satellite, the method also includes determining a virtual observation for the parameter. The virtual observation is determined for the navigation device being located at the estimated position. The method further includes determining whether the signals transmitted by the navigation satellite and received by the navigation device include multipath signals based upon the measurement of the parameter and the virtual observation for the parameter.

Abstract: A method, apparatus and computer program product provide one or more of navigation-data parameters or correction-model parameters for one or more navigation satellites. In the context of a method, the method includes receiving (i) navigation data regarding one or more of a position of a respective navigation satellite or a clock offset of a clock of the respective navigation satellite and (ii) correction data regarding corrections to one or more of the position or the clock offset of the respective navigation satellite. The method also includes predicting an orbit and the clock of the respective navigation satellite based on the navigation data and the correction data. The method further includes fitting at least one of the navigation-data parameters or the correction-model parameters to the predicted data and, following the fitting, providing the at least one of the navigation-data parameters or the correction-model parameters to one or more navigation devices.

Abstract: A method, apparatus and computer readable storage medium are provided for determining whether or not GNSS navigation data are potentially manipulated. In the context of a method, GNSS reference data is received that represents one or more GNSS signals observed by a reference receiver at a reference position. The method also receives GNSS navigation data and determines, at least partially based on said GNSS reference data and the GNSS navigation data, a position estimate of said reference position. The method further includes determining, at least partially based on said reference position and the position estimate of said reference position, whether or not the GNSS navigation data are potentially manipulated.

Abstract: A method, apparatus and computer readable storage medium are provided to determine whether or not said at least one GNSS signal is potentially manipulated. In the context of a method, at least one global navigation satellite system, GNSS, signal related to a first GNSS system time is received. The method determines at least one system time difference between the first GNSS system time and a reference time at least partially based on said at least one GNSS signal. The method also obtains at least one reference system time difference and then determines, at least partially based on the at least one system time difference and the at least one reference system time difference, whether or not said at least one GNSS signal is potentially manipulated.

Abstract: A method, apparatus and computer readable storage medium are provided for determining whether GNSS related positioning of a mobile device is expected or unexpected. In the context of a method, a representative of GNSS positioning accuracy for a mobile device is determined at least partially based on observation GNSS data and on correctional GNSS data. The method also includes determining, at least partially based on the representative of GNSS positioning accuracy, whether a GNSS related positioning is expected or unexpected for positioning of the mobile device.

Abstract: A method, apparatus and computer readable storage medium are provided for determining whether or not GNSS navigation data are potentially manipulated. In the context of a method, GNSS reference data is received that represents one or more GNSS signals observed by a reference receiver at a reference position. The method also receives GNSS navigation data and determines, at least partially based on said GNSS reference data and the GNSS navigation data, a position estimate of said reference position. The method further includes determining, at least partially based on said reference position and the position estimate of said reference position, whether or not the GNSS navigation data are potentially manipulated.

Abstract: A method performed by a mobile device and a corresponding apparatus are provided with the method including receiving first GNSS navigation data containing ephemeris data of at least one GNSS satellite and/or clock data of the at least one GNSS satellite for a first time period and determining extended first GNSS navigation data at least partially based on the first GNSS navigation data. The extended first GNSS navigation data contains ephemeris data and/or clock data of the at least one GNSS satellite for an extension time period. The method further includes receiving second GNSS navigation data containing ephemeris data of the at least one GNSS satellite and/or clock data of the at least one GNSS satellite for a second time period and determining, at least partially based on the extended first GNSS navigation data, whether or not the second GNSS navigation data are potentially manipulated.