An apparatus and method are described for processing a global navigation satellite system (GNSS) signal, the GNSS comprising multiple satellites, wherein each satellite transmits a respective navigation signal containing a spreading code. The method comprises receiving an incoming signal at a receiver, wherein the incoming signal may contain navigation signals from one or more satellites; encrypting the incoming signal at the receiver using a homomorphic encryption scheme to form an encrypted signal; and transmitting the encrypted signal from the receiver to a remote server.

A sensor arrangement for position determination of a rail vehicle includes at least two sensors that can be attached to the rail vehicle. Each of the sensors is configured to ascertain a position speed and to be disposed on the rail vehicle at different positions transverse to the direction of travel. At least one processing apparatus which is connected to the sensors is configured to process the position speeds ascertained by the sensors. An apparatus for position determination of a rail vehicle, a rail vehicle, and a method for position determination for a rail vehicle are also provided.

The disclosure provides methods, apparatus, and products for evaluating trustworthiness of GNSS-based location estimates. In one aspect, a method comprises obtaining observation information corresponding to one or more access points observed by a computing device during a time period; obtaining a GNSS-based location estimate indicating an estimated location of the computing device during at least a portion of the time period; determining an access points count corresponding to a number of the one or more observed access points that satisfy a distance criteria relative to the GNSS-based location estimate; comparing the determined access point count to a pre-defined threshold access points count; and based on results of the comparison, providing, by the processor, an indication of whether or not the GNSS-based location estimate is trustworthy. The method may be performed by one or more processors in a cloud-based computing system in response to an API call from the computing device.

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.

The present invention sequentially and repeatedly accepts a plurality of types of information that can change with time, including position information obtained using a satellite signal, and correlates and records the accepted plurality of types of information with time information.

A non-transitory computer-readable medium and apparatus for restoring navigational performance for a navigational system. The apparatus including a receiver for receiving by a first navigational system and a second navigational system a collection of data points to establish a real-time navigational route for the aircraft, and a computer for comparing navigational performance values or drift ranges. The computer capable of establishing a new navigational route based on the collection of data points.

The present disclosure generally pertains to systems and methods for autonomously detecting and correcting anomalies in position information provided to aircraft using radio-frequency signals. By enabling autonomously detecting and correcting for anomalies in the operation of a ground-based solution entirely independent of GPS, systems of the present disclosure can make the provided position information more accurate and robust, thereby enhancing the effectiveness and safety of navigation systems using the provided position information. More precisely, systems of the present disclosure may employ a series of ground-based beacon transmitters to provide radio-frequency (RF) signal pulse with a highly regular frequency. A locating receiver can detect the arrival times of these pulses and use this information to detect and report certain anomalies. These reports may then be used to autonomously correct the detected anomalies.

A method includes, by a mobile device, receiving a Global Navigation Satellite System (GNSS) signal, and receiving, from a wireless device, via a PC5 interface, a message including a location of a reference structure, a calculated location of the mobile device, or a combination thereof. The method also includes determine whether the GNSS signal is a spoofing signal based on: a spoof indication of the GNSS signal, and whether a difference between a location of the mobile device determined based on the GNSS signal and one of the location of the reference structure, the calculated location of the mobile device, or a location of the mobile device determined based on the location of the reference structure is greater than a threshold value.

A method of navigating from a known initial position at a known initial time to a new position at a predetermined delta time of an observer, the method comprising the steps of determining a number of virtual celestial objects for a desired degree of accuracy, generating orbital data for each of the VCOs, receiving at the initial time plus the delta time a parameter from a sensor that provides at least one parameter of the motion of the observer from the prior position, retrieving the orbital data previously generated for the initial time plus the delta time, calculating the new position to within the desired degree of accuracy using the initial position, the parameter, and the VCO orbital data, and, optionally, correcting the inertial navigation system position by using the calculated new position. The method is iteratively repeated as the observer moves.

Systems and techniques are described for detecting one or more timing errors. For example, a system can receive, from a navigation system, navigation timestamp information at a first instance and a second instance. The system can determine a navigation system time difference based on the navigation timestamp information at the first instance and the second instance. The system can further receive, from a wireless device, network timestamp information at the first instance and the second instance. The system can determine a network time difference based on the network timestamp information at the first instance and the second instance. The system can further determine whether time reporting by the navigation system is correct based on the navigation system time difference and the network time difference.