A method for GNSS-based localization of a vehicle includes receiving a first set of satellite orbit data, using the first set of satellite orbit data when determining a first localization result, receiving a second set of satellite orbit data, checking a plausibility of the first set of satellite orbit data using the second set of satellite orbit data, and manipulating the first set of satellite orbit data and/or the first localization result and/or a localization filter when the plausibility check was not successful.

A method for GNSS-based localization of a vehicle includes receiving a first set of satellite orbit data, using the first set of satellite orbit data when determining a first localization result, receiving a second set of satellite orbit data, checking a plausibility of the first set of satellite orbit data using the second set of satellite orbit data, and manipulating the first set of satellite orbit data and/or the first localization result and/or a localization filter when the plausibility check was not successful.

A method of determining a posterior error probability distribution for a parameter measured by a Global Navigation Satellite System (GNSS) receiver. The method comprises receiving a value for each of one or more GNSS measurement quality indicators associated with the GNSS measurement of the parameter. The or each received measurement quality indicator value is provided as an input into a multivariate probability distribution model to determine the posterior error probability distribution for the GNSS measurement, wherein the variates of the multivariate probability distribution model comprise error for said parameter, and the or each measurement quality indicator.

A method of determining a posterior error probability distribution for a parameter measured by a Global Navigation Satellite System (GNSS) receiver. The method comprises receiving a value for each of one or more GNSS measurement quality indicators associated with the GNSS measurement of the parameter. The or each received measurement quality indicator value is provided as an input into a multivariate probability distribution model to determine the posterior error probability distribution for the GNSS measurement, wherein the variates of the multivariate probability distribution model comprise error for said parameter, and the or each measurement quality indicator.

A method for determining a four-dimensional ionosphere model of an electron distribution in the Earth's atmosphere is disclosed, which is used to correct runtime measurements of signals emitted by satellites, for position determinations by means of signal receivers. The method comprises: a) defining at least one distribution function based on at least one function parameter which is suitable to describe a distribution of electrons over the height of the Earth's atmosphere; b) receiving data from a plurality of runtime measurements by means of a plurality of movable dual-frequency signal receivers, in order to determine parameters that are representative for a total quantity of electrons along a signal transmission path from a satellite to a dual-frequency signal receiver; c) determining location-dependent and time-dependent function parameters for the distribution function at least by means of the parameters; and d) providing the function parameters determined in step c) as a four-dimensional ionosphere model.

A method for determining a four-dimensional ionosphere model of an electron distribution in the Earth's atmosphere is disclosed, which is used to correct runtime measurements of signals emitted by satellites, for position determinations by means of signal receivers. The method comprises: a) defining at least one distribution function based on at least one function parameter which is suitable to describe a distribution of electrons over the height of the Earth's atmosphere; b) receiving data from a plurality of runtime measurements by means of a plurality of movable dual-frequency signal receivers, in order to determine parameters that are representative for a total quantity of electrons along a signal transmission path from a satellite to a dual-frequency signal receiver; c) determining location-dependent and time-dependent function parameters for the distribution function at least by means of the parameters; and d) providing the function parameters determined in step c) as a four-dimensional ionosphere model.

A receiver authenticates a wideband (WB) signal from global navigation satellites (GNSS) using a narrowband (NB) signal that is also transmitted from the satellites. The NB signal includes segments that are transmitted in time and frequency slots of successive transmission frames. The NB signal is less susceptible to a smart WB jammer. Also, the NB signal segments may also be transmitted at a relative power level with respect to the WB signal, where the relative power level may vary in a known pattern so as to distinguish the WB signal of the satellite from a stronger WB signal from a smart jammer.

In an aspect, a user equipment (UE) receives a spoofing alert message from either a server or an internet-of-things (IOT) device that indicates whether a spoofed Global Navigation Satellite System (GNSS) condition is present. Based on determining that the spoofing alert message indicates that a spoofed GNSS condition is present, the UE determines, based on the spoofing alert message, a location of a spoofer broadcasting a spoofed GNSS signal, determines, based on the location of the spoofer and a current location of the UE, that the UE is within a receiving area of the spoofed GNSS signal, and determines a position of the UE without using the spoofed GNSS signal.

A UE includes: a memory; a receiver configured to receive wireless signals; and a processor communicatively coupled to the memory and the receiver and configured to: receive, via the receiver, one or more indications corresponding to one or more failures of a first positioning signal source; disable a first positioning-signal-processing function of the UE for the first positioning signal source based on the one or more indications; and perform a second positioning-signal-processing function of the UE using a positioning signal from the first positioning signal source while the first positioning-signal-processing function of the UE is disabled.

Disclosed is reducing starting time for a GNSS receiver that has an imprecise initial starting location by requesting starting assistance from a CDN that caches predictive data including first data indicated predicted LOS visibility from the receiver to individual satellites, wherein the request includes the imprecise initial staring location, receiving, from the CDN, data that includes a first block of the predictive data for the imprecise initial staring location and further adjoining second blocks of predictive data for areas surrounding the imprecise staring location, determining, by the GNSS receiver, commonly available satellites that have visibility from locations in both the first block and the second block, and calculating a first starting position using weighted values for the satellites, the commonly available satellites having higher weighted value than satellites without visibility in both locations, whereby position uncertainty of the first starting position is reduced from the imprecise initial starting location.