Centre National Detudes Spatiales

Thales

M3 Systems

Centre National De La Recherche Scientifique

Onera

Institut Superieur De L'aeronautique Et De L'espace

Lionel Ries

François-Xavier Marmet

Michel Monnerat

Willy Vigneau

Nabil Jardak

Jean-Luc Issler

Christophe Macabiau

Olivier Julien

Thibaud Calmettes

Laurent Lestarquit

Thomas Grelier

Benjamin Gadat

Denis Laurichesse

Nelson Fonseca

Nicolas Capet

Nicolas Van Wambeke

Damien Kubrak

Hervé Aubert

Gaël Scot

Guillaume Carrie

Stéphane Corazza

Olivier Pascal

Jacques Beas-Garcia

Philippe Paimblanc

Marion Aubault

Sami Hebib

Jose-Angel Avila-Rodriguez

Guenter W Hein

Sébastien Rougerie

Marion Roudier

Anchalee Puengnim

François Vincent

Paul Thevenon

Michel Bousquet

Géraldine Artaud

Vincent Calmettes

Herve Aubert

Thibauld Calmettes

Stéphanie Bidon

Jean-Rémi De Boer

Olivier Desenfans

Stéphane Cozzazza

The invention discloses a positioning device configured to acquire its own GNSS position, the GNSS positions of rovers in an area around the positioning device and the relative positions of the positioning device to the rovers. The positioning device is configured to calculate a best-fit position based on this data and their confidence indexes. The positioning devices may communicate directly or through a navigation assistance centre. The best-fit position may be provided with indexes of confidence, availability and integrity. In some embodiments, the positioning device of the invention may be robust enough to generate commands to the driving controls of an autonomous vehicle.

Collaborative improvement of a vehicle's positioning

The invention discloses an improved GNSS receiver which determines a location of the receiver by combining a first location determined either from the standard PVT of a multi-frequency receiver and/or from a positioning aid like a map matching algorithm, inertial navigation system, WiFi localization system or other, and a second location determined by integrating the velocity from the standard PVT. The combination is based on a duty cycle or a combination of the duty cycle with a weighting of the error budgets of the first position and the second location. The improved receiver is preferably based on a standard receiver with an add-on software module which receives and processes data transmitted from the standard receiver by, for example, NMEA messages. The improved receiver allows a determination of a more precise and smoother trajectory in a simple way.

GNSS receiver using a combination of velocity integration and precise point positioning

A GNSS receiver and the associated method, for calculating an unbiased position and time measurement from a plurality of satellite positioning signals, the receiver comprising: A GNSS receiver further comprising a second computer logic configured to calculate a second unbiased position and time from the first position and time, and the second signal processing signals.

GNSS receiver with an improved capability to resolve sub-carrier tracking ambiguities

The invention discloses a receiver of GNSS positioning signals which has embedded computer logic to select between a first operating mode, which uses all available frequencies, and a second operating mode, which uses only part of the available frequencies but in combination with available correction data. The selection is based on a comparison of an index of quality of reception at the receiver and a computed or predicted precision/confidence level of the corrections. A plurality of corrections types are possible, including a type using a local model and a type using collaborative corrections. In some embodiments, a selection and/or a combination of a plurality of local models may be made to optimize the accuracy of the corrections.

GNSS receiver with an on-board capability to implement an optimal error correction mode

The positioning signals broadcast by the GNSS constellations on civilian frequencies are likely to be counterfeited, while the use of authentic signals is becoming increasingly critical for certain applications. According to the invention, the authentication of GNSS signals is performed by analysis of consistency between the measurements of parameters characteristic of the signals (direction of arrival, amplitude, phase) and their state model, said state model taking account of an emulation by software and electronic means of displacements of the phase centre of the antenna and/or of the main lobe of the radiation pattern. Advantageously, these displacements are generated by a pseudo-random code. Advantageously, the analysis of consistency between measurements and models is a multiple-criterion analysis, the combination of criteria being chosen as a function of a reception quality indicator and/or of a presumed location.

Method for authenticating signals received from a constellation of satellites

A GNSS receiver comprising a circuit configured to receive a positioning signal comprising a carrier modulated by a subcarrier and a PRN code; a subcarrier and code tracking loop, comprising a first discrimination circuit, configured to calculate a first pseudo range from said received positioning signal and a first reference signal; a code tracking loop, comprising a second discrimination circuit, configured to calculate a second pseudo range from said received positioning signal and a second reference signal; and a calculation circuit configured to evaluate a difference between said first pseudo range and said second pseudo range, and to modify the output of the first discrimination circuit accordingly. The invention further addresses a method for calculating a pseudo-range in such a GNSS receiver.

Device for tracking a satellite radionavigation signal in a multipath environment

The invention discloses a recovery assistance device for helping in rescuing victims of avalanches, earthquakes or boat capsizes. The device is capable of calculating a position from combinations of a previous position and distances to other devices. Different configurations are possible, with a basic configuration consisting of a smart phone having waveform generation capabilities, processing and GNSS receiving capabilities. The device is programmed to be used in a defined mission by an application. The device can also receive a number of add-ons as a battery add-on, a modem add-on, a sound wave generation add-on, antennas, and protection, possibly waterproof, if adequate. Devices of the same type can be carried by people to be rescued and rescuers. The device is therefore quite versatile and can increase significantly the efficiency of rescue teams in different use case scenarios.

Recovery assistance device, method and system

A receiver, and associated process, for tracking a GNSS positioning signal comprising a carrier modulated by a subcarrier and a spreading code, the receiver comprising:

GNSS receiver calculating a non-ambiguous discriminator to resolve subcarrier tracking ambiguities

A global navigation satellite system ('GNSS') positioning method is provided, based upon a GNSS radio signal that comprises a navigation message transmitted as a succession of data packets. Each data packet is present in the GNSS radio signal as a sequence of symbols obtained by application of a code preceded by a synchronization symbol header. The data packets are organized internally into data fields. At least certain data packets of the succession of data packets contain a synchronization bit field translated by application of the code into a synchronization symbol pattern.

GNSS radio signal for improved synchronization

A method includes estimating the position of the moving object on the basis of the reception of navigation signals emitted by a constellation of satellites, the navigation signals being modulated by a code and the receiver comprising a local replica of the code. The determination of the confidence indicator consists in estimating a speed of displacement of the receiver over an identified trajectory segment, deducing therefrom a Doppler delay function corresponding to the motion of the receiver, in correcting the auto-correlation function of the GNSS navigation signal received from each satellite of the constellation by means of the delay function, in comparing the corrected auto-correlation function with a theoretical auto-correlation function by applying a quadratic criterion corresponding to the confidence indicator.

Method for determining a confidence indicator relating to the trajectory followed by a moving object

In the field of active phase-control antennas, a method is provided for calibrating the phase center of an active antenna including a plurality of sub-elements able to receive a useful signal emitted by a satellite, the calibration being defined as a function of the reception characteristics of a reference signal at the level of each sub-element, the reference signal being emitted by the same satellite on a frequency band substantially equal to the frequency band of the useful signal and whose theoretical reception characteristics are known.

Method for calibrating an active antenna

A radionavigation signal tracking device comprises a first and a second tracking stage for radionavigation signals. The first tracking stage comprises a first carrier phase-locked loop. The latter produces a first error signal arising from a phase difference between the first carrier and its replica. The phase of the replica of the first carrier is adjusted with the first error signal. The second tracking stage comprises a second carrier phase-locked loop. The latter produces a second error signal arising from a difference between the first phase difference and a phase difference between the second carrier and the replica thereof. The phase of the replica of the second carrier is adjusted with the first and second error signals.

Radionavigation signal tracking device

An improved decoding method is provided making it possible to solve the problem of the error floor of a turbo-code or of an LDPC code, or more generally of a correcting code from the family of 'turbo-like codes', while preserving the same spectral efficiency, without any decrease in the useful throughput of the encoded stream. This result is obtained by an identification, on input to the decoder, of the bits on which an error has a strong impact, and a modification of the likelihoods corresponding to these bits so as to improve the convergence of the decoder.

Method of decoding a correcting code, for example a turbo-code, by analysis of the extended spectrum of the words of the code

A global navigation satellite system ('GNSS') positioning method is provided, based upon a GNSS radio signal that includes a navigation message transmitted as a sequence of frames, each frame being composed of a plurality of subframes, each of which contains a first set of ephemeris and clock correction data (DECH) sufficient for computing a satellite position and a satellite clock error. Each subframe furthermore contains a second set of DECH, more compact than the first set of DECH, but sufficient for computing satellite position and satellite clock error to a lesser degree of accuracy, at least two copies of the second set of DECH being present in each subframe, such that the timing difference between two consecutive copies does not exceed 70% of the subframe duration.

GNSS radio signal with an improved navigation message

A method is provided for demodulating a signal carrying a message transmitted by a terrestrial beacon, executed by a system comprising a constellation of satellites suitable for detecting said signal and for repeating it towards receiving stations on the ground, and an analysis module suitable for receiving signals from said stations. Each receiving station transmits the signals that it receives from the satellite to the analysis module, said module realigning said signals in frequency and/or in time relative to one another, combining the realigned signals to generate a synthetic signal having an enhanced signal-to-noise ratio, and determining the content of said message and/or the modulation parameters of said synthetic signal. The method applies notably to the accurate and reliable location of distress beacons by a satellite system.

Method for the coordinated processing of signals transmitted by beacons

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Viviers les Montagnes, France

Lionel Ries