The present disclosure relates to a method for synchronizing an encoded signal, in particular a GNSS signal. The method comprises receiving an input signal comprising a first signal component and a second signal component, wherein a sequence of N bits of the first signal component and a sequence of M bits of the second signal component are known a priori. The method further comprises determining a first logical sequence based on a plurality of cross-product operations formed between pairs of vectors obtained from a plurality of received symbols of the first signal component and the second signal component of the received input signal. The method also comprises identifying a position of a second logical sequence within the first logical sequence, the second logical sequence resulting from logical operations performed between at least a part of the known sequence of N bits of the first signal component and a corresponding number of bits of the known sequence of M bits of the second signal component in order to synchronize to a frame of the received input signal.

Users that abandon GPS searches on GPS enabled devices before arriving at the search location are lost to business entities. The system uses the data obtained from abandoned GPS searches to identify these lost users. Sometimes a unique script embedded in the GPS application loaded onto the user's GPS enabled device scrapes the data from the GPS search and from user entries on the GPS enabled device. The system uses the obtained data to market or remarket to the lost consumers by sending personalized messages via a preferred communication medium.

Embodiments of the present invention provide a method, system and computer program product for bit transition enhanced direct position estimation (DPE) from global navigation satellite system (GNSS) signals and includes the reception in a GNSS receiver of signals from multiple, different satellites in multiple satellite constellations adapted for use with the GNSS. The method estimates the GNSS receiver parameters position, velocity, clock bias, clock drift, and optionally and if unknown, the receiver time. The method generates a model of the received GNSS signals that depends on the receiver parameters. Uniquely, the method includes the synchronization of both a primary code and also a secondary code in the received GNSS signal model, in addition to time delays, Doppler shifts, and other relevant parameters for positioning. Finally, if the secondary code of a particular signal is unknown, the method determines the combination of bit transitions that maximizes the optimization problem.

An apparatus that performs spoof detection of satellite signals based on clock information derived from the satellite signals. The apparatus may include a position, velocity, time (PVT) component that derives the clock information from the satellite signals and provides the clock information to a spoof detection mechanism. In some embodiments, the clock frequency estimate is modeled as a Wiener process.

System includes one or more processors configured to receive location data from a device communication unit and from at least a first communication unit and a second communication unit that are positioned relative to a vehicle. The location data includes a device spatial location of the device communication unit, a first spatial location of the first communication unit, and a second spatial location of the second communication unit. The one or more processors are further configured to determine a vehicle spatial location of a designated point of the vehicle. The one or more processors are further configured to generate a virtual model. The virtual model, when used by a positioning system to locate the vehicle, indicates the vehicle spatial location relative to an estimated location of the vehicle.

Provided are systems, methods, and devices for identifying correct satellite signals to improve the accuracy of a satellite navigation system. In some embodiments, identifying correct satellite signals may include receiving a plurality of satellite signals; demodulating the satellite signals to extract a first plurality of parameters; determining a first subset of parameters from the first plurality of parameters, wherein the first subset of parameters is based on a first geographic location; determining a second subset of parameters from a second plurality of parameters outside the first subset, the second plurality of parameters comprising one or more parameters of the first plurality of parameters outside the first subset, wherein the second subset of parameters is based on a second geographic location; and identifying an exemplary subset from the first subset and the second subset, wherein the exemplary subset comprises parameters corresponding to correct satellite signals.

Locating a vehicle to be located (V.sub.P), which has at least a GNSS receiver, via a location system including at least a computer by: receiving a message that includes at least a GNSS signal and that is transmitted by the vehicle to be located (V.sub.P), receiving a message that is transmitted by at least one located vehicle (V.sub.L), which has a GNSS receiver, the message including a location of the vehicle, the location being associated with a high confidence level, and a GNSS signal generated by the GNSS receiver of the vehicle, determining a location of the vehicle to be located, on the basis of the location of at least one located vehicle (V.sub.L), the GNSS signal from the located vehicle, and the GNSS signal from the vehicle to be located, and transmitting the determined location to the vehicle to be located (V.sub.P).

Techniques for detecting GNSS spoofing using inertial mixing data are disclosed. One or more navigation parameters are determined by at least one GNSS receiver and a plurality of IRS from at least two periods of time. The navigation parameters from the GNSS receiver(s) and the IRS are compared at each time period, and the difference(s) between the compared navigation parameters are further compared to generate at least one differential value. A system can detect GNSS spoofing by comparing the at least one differential value to a suitable threshold. In one aspect each IRS navigation parameter is compared with a corresponding GNSS navigation parameter, wherein the plurality of differential values is mixed before threshold comparison. In another aspect, each IRS navigation parameter is mixed before comparison with a GNSS navigation parameter, and the resulting differential value is then compared against a threshold.

Apparatus and method for communication in non-terrestrial networks are disclosed. A set of Doppler shift curves for different distances to one or more satellite orbits is obtained. Measurements of satellite transmission are performed to obtain estimate of instantaneous Doppler shift of the transmission, the measurements including a timestamp. A Doppler shift curve corresponding to the measurements is calculated. A time offset on the selected curve is determined utilising the timestamps of the measurements, the time offset indicating the position of the Doppler shift of the apparatus on the curve. The Doppler shift of the satellite transmission is determined utilising the selected curve and the time offset

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.