Abstract: Examples in accordance with this disclosure provide a system for detecting a spoofed signal, the spoofed signal comprising position-navigation-timing (PNT) data. The system can include a first antenna and a second antenna, both configured to receive one or more first signals from one or more navigation satellites. The first antenna and second antenna can be configured to be separated by a first distance. The system can include a first receiver coupled to the first antenna and a second receiver coupled to the second antenna, where each antenna is configured to receive one or more signals from the respective antenna. Each of the first receiver and the second receiver are configured to extract a respective carrier phase data.

Abstract: A method or system can include or be configured to receive a set of satellite observations, receiving sensor data, determining a position estimate and associated positioning error for a rover based on the set of satellite observations and the sensor data, determine a protection level associated with the position estimate based on a set of potential faults, and optionally provide an alert when the positioning error exceeds the protection level.

Abstract: A method for determining a position of a phase centre of an antenna arranged in a mobile device, in particular a vehicle, wherein the antenna is operable to receive satellite signals in a global navigation satellite system, the method comprising: receiving, with the antenna, satellite signals from satellites of the global navigation satellite system; determining a direction from which the satellite signals are received based on the received satellite signals; and determining the position of the phase centre of the antenna based on the direction from which the satellite signals are received and stored correlation information indicative of a correlation between the position of the phase centre and the direction from which the satellite signals are received.

Abstract: Aspects of the present disclosure may improve the accuracy of the known azimuth determination techniques by employing more than two GNSS antennas positioned on a base station antenna. Techniques may use one or more combinations of the GNSS antennas to determine an azimuth of the base station antenna, which serve to improve accuracy of an azimuth determination.

Abstract: A plurality of GNSS satellite signals feeds multiple signal processing engines, each operating in certain processing mode including carrier smoothed pseudorange positioning, precise point positioning (PPP), pseudorange differential (DGNSS), carrier phase differential (RTK). Each processing engine (or processing thread of the same engine) runs the same unified numerical algorithm and uses the same or different sets of parameters. All engines can use the same set of signals, or the set of signals can be split into non-intersecting subsets, or the set of signals can be split into the overlapping subsets. Each engine produces estimates of certain parameters, namely carrier phase ambiguities and ionospheric delays for each satellite. These estimates are then combined into a resulting estimate which in turn is used for calculation of the final position reported by the receiver.

Abstract: Systems and methods for vehicle attitude determination are provided.

Abstract: A status calculating apparatus is provided. The apparatus includes three or more antennas disposed at different positions on a movable body, each antenna receiving positioning signals, correlators for calculating carrier wave phase differences for every antenna based on correlation of the positioning signals with a replica signal, carrier wave phase measurement value calculating modules for calculating carrier wave phase measurement values, a baseline vector calculating module for calculating baseline vectors based on the carrier wave phase measurement values, and an attitude angle calculating module for calculating a yaw angle for every baseline vector and calculating a representative yaw angle based on the plurality of calculated yaw angles.

Abstract: A method for calibrating spatial errors induced by phase biases having a detrimental effect on the measurements of phase differences of radio signals received by three unaligned receiving antennas of a vehicle. An inter-satellite angular deviation of a pair of satellites is estimated in two different ways: on the basis of the respective positions of the vehicle and of the satellites to obtain a theoretical inter-satellite angular deviation; and on the basis of the respective directions of incidence of the satellites relative to the vehicle, which are determined from phase measurements, to obtain an estimated inter-satellite angular deviation. The space errors are estimated on the basis of said theoretical and estimated inter-satellite angular deviations. Also, a method and system for estimating the attitude of a vehicle, in particular a spacecraft.

Abstract: A system and method for determining the heading angle of a vehicle includes first and second antennas associated with the vehicle. The first and second antennas are configured to receive signals comprising global positioning system data. A receiver front end is configured to receive the signals comprising global positioning system data. An electronic data processor is capable of receiving the global positioning system data from the receiver front end. The data processor is configured or programmed to execute a method to determine the attitude of the vehicle which may include the heading angle of the vehicle.

Abstract: Described is a generalized approach for integer parameter estimation, especially in the context of Global Navigation Satellite Systems (GNSS). The problem solved is the case where a definitively correct integer solution cannot be identified for all ambiguity parameters in a reliable way. The proposed solution is to apply a linear transformation to the ambiguities (multiply with a matrix) such that the images of the first and the second candidate (or more) are identical. That way, from the first and second (and possibly more) candidates of the integer least-squares solution, a subset of ambiguity combinations is derived that can be fixed. Thus, it is no longer necessary to choose between the solutions as they coincide for the new ambiguities. The advantage of this approach is maximizing all information still available when finally deriving additional parameters such as position, clock error, atmospheric errors and/or time correlated noise.

Abstract: A differential global positioning system (DGPS) processor can include an almost fixed integer ambiguity (AFIA) module for generating in real-time a multiple dimensional state vector of integer ambiguities and multiple dimensional corrections. The AFIA module can use double difference (DD) measurements for pseudo-range (PR) and carrier phase (CP) pairs generated from at least three global positioning system (GPS) receivers. A DGPS processor can be included in a high data rate real time attitude determination (RTAD) system to achieve high heading accuracy with high integrity.

Abstract: A linear least squares (LLS) estimator provides a low complexity estimation of the location of a mobile terminal (MT), using one of the fixed terminals (FTs) as a reference FT to derive a linear model. A method for selecting a reference FT is disclosed, which improves the location accuracy relative to an arbitrary approach to selecting the reference FT. In addition, a covariance-matrix based LLS estimator is proposed in line-of-sight (LOS) and non-LOS (NLOS) environments to further provide accuracy, taking advantage of the correlation of the observations. Different techniques for selecting the reference FT under non-LOS (NLOS) conditions are disclosed. A map-based two-stage LLS estimator assists in selecting the reference FT under NLOS conditions.

Abstract: A wireless communication device uses a time-invariant delay-Doppler channel response estimate for received signal demodulation. The device provides coherent signal demodulation by accounting for frequency and time selectivity in a land-based mobile communication environment, which arise mainly because of delay and Doppler shifts, respectively. In one embodiment, the wireless communication device includes a channel estimator that estimates channel response in a wireless communication network by estimating a delay-Doppler response of a wireless communication channel to obtain a delay-Doppler channel response estimate and converting the delay-Doppler channel response estimate to a time-varying channel response estimate, e.g., a time-varying frequency or impulse response. The delay-Doppler response may be estimated in a continuous or discrete domain.