Some embodiments of the invention relate to methods carried out by an NSS receiver and/or a processing entity capable of receiving data therefrom, for estimating parameters derived from NSS signals useful to determine a position, and for estimating an expected accuracy. The method comprises receiving input data comprising NSS signals observed by the NSS receiver and/or information derived from said NSS signals; operating an estimation process, hereinafter referred to as “estimator”, using state variables and computing the values of its state variables based on the received input data; obtaining a combination of residuals from the estimator, each residual being associated with at least one observed NSS signal; and estimating an expected accuracy based on the combination of residuals and/or information derived therefrom. Systems and computer programs are also disclosed. Some embodiments may for example be used for safety-critical applications such as highly automated and autonomous driving.

A vehicle positioning method includes obtaining satellite filtering parameters and satellite data, the satellite data comprising at least one of (i) a pseudo range observation value or (ii) a Doppler observation value indicating a Doppler effect. The method further includes determining a first parameter correction amount corresponding to the vehicle at a first time point to obtain positioning information of the vehicle at the first time point. The method further includes determining a second parameter correction amount corresponding to the vehicle at the second time point according to a constraint matrix corresponding to the motion state of the vehicle, and obtaining positioning information of the vehicle at the second time point by modifying the positioning information at the first time point using the second parameter correction amount.

Method, systems, and computer-readable media containing instructions which, when executed by a computing device, cause it to receive data from an inertial measurement unit, including GPS data, velocity data, and bearing data, receive data from a digital magnetic compass, including bearing data, receive data from a Doppler sensor, including velocity data and distance data, determining whether GPS location data is in consensus with a previous derived multi-source reckoning system location, determining a consensus distance value from a weighted average of data from the inertial measurement unit and the Doppler sensor, determine a consensus heading value from a weighted average of data from the inertial measurement unit and the digital magnetic compass, determine a consensus geolocation value from a weighted average of data from the inertial measurement unit and the previous derived multi-source reckoning system location, and determine a derived multi-source reckoning system location.

According to certain embodiments, a method performed by a wireless device comprises receiving Assisted-Global Navigation Satellite System (A-GNSS) information in system information broadcast by a network, receiving signals from a set of GNSS satellites (the set of GNSS satellites comprises at least three GNSS satellites), and determining a location of the wireless device using the A-GNSS information and information received in the signals from the set of GNSS satellites. The method further comprises determining Doppler time and frequency offsets compared to a network satellite. The Doppler time and frequency offsets are determined based on the location of the wireless device. The method further comprises initiating a connection process with the network satellite by transmitting a random access signal with pre-compensated time and frequency, the pre-compensated time and frequency based on the determined Doppler time and frequency offsets.

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.

Methods, apparatuses and/or articles of manufacture, which may be employed in a mobile device and/or in a location server, enable acquisition assistance at the mobile device. In at least one implementation, which is not intended to limit claimed subject matter, acquisition assistance may include expected Doppler frequency shift and expected code phase in the case of a particular Global Navigation Satellite System (GNSS) satellite vehicle, as well as a search window for each of these, and a confidence value. The confidence value may indicate the likelihood of detecting signals from the satellite vehicle at the current expected location of the mobile device and within the given search windows and may enable one or more of faster location estimation, reduced battery consumption, and detection of weaker satellite signals.

A satellite system operates at altitudes between 100 and 350 km relying on vehicles including a self-sustaining ion engine to counteract atmospheric drag to maintain near-constant orbit dynamics. The system operates at altitudes that are substantially lower than traditional satellites, reducing size, weight and cost of the vehicles and their constituent subsystems such as optical imagers, radars, and radio links. The system can include a large number of lower cost, mass, and altitude vehicles, enabling revisit times substantially shorter than previous satellite systems. The vehicles spend their orbit at low altitude, high atmospheric density conditions that have heretofore been virtually impossible to consider for stable orbits. Short revisit times at low altitudes enable near-real time imaging at high resolution and low cost. At such altitudes, the system has no impact on space junk issues of traditional LEO orbits, and is self-cleaning in that space junk or disabled craft will de-orbit.

An assisted satellite positioning system based on detecting signals from a number of satellites includes: (a) a mobile receiver; and (b) a base station communicating with the receiver over a low-power wireless communication network, the base station providing ephemeris data of a selected number of the satellites, but not all, using a compressed data format. The ephemeris data may include data concerning doppler frequency variations or elevation variations of the selected satellites over a predetermined time interval. The doppler frequency variations and the elevation variations may be represented in the compressed format by coefficients of a polynomial function of time. The polynomial function may be weighted to have lesser relative errors in larger doppler frequencies than lesser doppler frequencies, or to have lesser relative errors in lesser elevations than larger elevations. In one implementation, the low-power wireless communication network—such as a LoRa network—that has a range of at least 10 miles.

Methods, devices, systems, media, and receivers for processing GNSS signals are described. One aspect of the present disclosure provides a method for processing satellite signals of a Global Navigation Satellite System (GNSS), the method comprising: receiving a first GNSS signal transmitted in a first GNSS operational band by a satellite of the GNSS and a second GNSS signal transmitted in a second GNSS operational band by the satellite; tracking the first GNSS signal; generating, from the tracking of the first GNSS signal, tracking parameters for the first GNSS signal; and decoding, at least based on the tracking parameters for the first GNSS signal, the second GNSS signal, wherein the first GNSS operational band is one of L1 band, L2 band or L5 band, and the second GNSS operational band is L6 band.

A device and the associated method for detecting spoofing of GNSS signals are provided. The device includes an RF chain to acquire and down convert a signal comprising one or more GNSS signals transmitted by GNSS sources, each of the GNSS signals comprising a navigation message modulated by a spreading code associated to a related GNSS source, an analog to digital converter, to digitize the down converted signal, and a computer logic, to: calculate over a grid of spreading code phase delays and Doppler shifts, cross-correlation functions between the digitized signal and locally generated replicas of the signal, for one or more of the spreading codes, identify cross-correlation peaks, and analyze the cross-correlation peaks to detect spoofing situations.