Centre National Detudes Spatiales

M3 Systems

François-Xavier Marmet

Nicolas Capet

Lionel Ries

Willy Vigneau

Nabil Jardak

Denis Laurichesse

Cédric Rouch

Gaël Scot

Marion Aubault

Jacques Beas-Garcia

Joël Dantepal

A user computing device, method and computer program to display a view to the user are provided. The invention allows a user to display a number of different views with photorealistic rendering of how the view should look like at a view time, based solely on view position, and descriptors of the view. In an aspect, the invention deduces from view position and view time the view descriptors (weather parameters, traffic parameters . . . ); selects, in a collection of images, an image of the view based on view position; modifies the image to match descriptors of the view (for example, by adding a rain effect if the image in the collection is under sunshine and the view should be displayed under rain). Thus, the invention allows displaying photorealistic images of how a view should look like at any time.

Dynamic StreetView with view images enhancement

A Global Navigation Satellite System (GNSS) positioning techniques is provided. A method to improve the time required to compute a position measurement in a GNSS receiver, and the time required to make this position measurement accurate is also provided. The method comprises computing a snapshot PVT (Position Velocity and Time) measurement, and use it to reduce the time required to acquire new signals to compute a conventional PVT measurement. A receiver implementing the method is further provided.

Self-assisted fast acquisition and first fix for a standalone GNSS receiver

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.

Receiver-independent spoofing detection device

An antenna assembly configured to transmit terrestrial positioning signals from a relay platform having a frame of reference, the transmit being in at least a first mode with a radiating pattern having at least a main lobe having a narrow aperture in a plane and a wide aperture in a plane. A relay platform comprising a receiver of a synchronization signal, a transmitter of positioning signals to an area of service comprising a number of rovers, and an antenna assembly configured to produce a radiating pattern adapted to transmit the positioning signals as a function of the environment of the relay platform and the rovers. In a number of embodiments the relay platforms may be organized in a network of platforms, possibly of masters and slaves that receive feed-back from the rovers in the AoS so as to optimize the configuration of the antenna elements dynamically to optimize the QoS of positioning based on a number of selected quality indexes.

Relay platform for transmitting positioning signals to rovers with an optimized radiation pattern

A terminal to calculate a position and detect spoofing, the terminal includes a receiver of first signals, notably signals of a GNSS type, from first sources, to compute a first information relative to its position, as for instance a pseudo range measurement, an ephemeris, a navigation message, spatial coordinates or temporal coordinates, and to calculate a position; a receiver of a second signal of a non-RF and non-GNSS type from a second source, notably from an optical display, the second signal comprising a second information transmitted using a predetermined encoding format to retrieve said second information; a processing logic configured to detect spoofing by comparing the first and second information. The associated transmitters, authentication server and spoofing detection methods are also provided.

Device and method to detect spoofing of a terminal

A positioning device includes a first GNSS receiver; a communication link configured to receive a spatial position, code measurements and carrier phase measurements of a second GNSS receiver; an input interface to a processing logic, the processing logic being configured to: calculate a position of the first positioning device from communicated data; and to estimate one or more parameters representative of multipath at the position of the first positioning device; wherein the communication link is configured to communicate to a second positioning device the parameters representative of multipath at the position of the first positioning device. Described developments comprise the use of multipath severity indicators, the determination of relative distances between receivers, validity conditions in time and/or space of multipath, various embodiments in a train or in a group of vehicles. Software aspects are discussed.

Multipath management for global navigation satellite systems

There is disclosed a system for locating an object on a surface waveguide. The surface waveguide is made of one or more 1D wires and/or 2D waveguides comprising conductive elements arranged in patterns. Emitters with known positions can couple with receivers coupled with the surface waveguide. The position of receivers can be determined, for example by multilateration or signal strength indication. Conductive elements can be sprayed or sewed or otherwise deposited onto surfaces such as a ground floor, a sidewalk or a road lane. Described developments comprise the use of absorbers, protective layers, unidirectional emitters, contactless coupling, and various arrangements comprising frequency-selective layers, arrangements in lattices, trellis or anisotropic surfaces. Signal processing aspects and software embodiments are also described.

Positioning system

An add-on device configured to reduce the power level of reflected paths of GNSS signals reaching a GNSS receiver's antenna, the associated GNSS receiver set, some equipment embedding the add-on device, and the associated method to reduce the power level of reflected GNSS signals are provided. The GNSS signals are transmitted according to a first polarization, and the add-on device comprises a material configured to be transparent to the first polarization and to reflect GNSS signals polarized according to a second polarization orthogonal to the first polarization.

GNSS antenna add-on

A navigation system using Visible Light Communications (VLC), the associated transmitters and receivers, the navigation system comprising a plurality of VLC transmitters (to) and one or more GNSS receiver (), each of the VLC transmitters being configured to transmit a positioning signal comprising a navigation message including time information, where the time information is a transmission time of a specific part of said navigation message derived from a GNSS reference time. The receivers () according to the invention are configured to calculate a position from either VLC pseudo ranges, GNSS pseudo ranges, or a combination thereof. The associated methods for transmitting positioning signals in a navigation system according to the invention, and for determining a position from a plurality of positioning signals transmitted by said navigation system.

Visible light communication based positioning

A device for handling multipath of a G.N.S.S. signal, is configured to: determine a spatial position, a clock time and measured multipath parameters comprising a relative delay and relative amplitude; communicate to a remote server the spatial position, clock time and multipath parameters; and receive processed multipath parameters as determined by the remote server. Systems comprising a plurality of such devices and their variants are described. Further aspects are described, in particular the exclusion of one or more satellites, the use of threshold schemes, pull/push modes, configurable refresh rates, quantization of positions, activation of additional sensors, filtering options, determination of merit factors for example as a function of the number of satellites in view and/or of signal-to-noise ratio, peer-to-peer schemes, as well as graphical display, audible sound or haptic feedbacks.

Multipath management in global navigation satellite systems

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

A GNSS receiver, and an associated method are presented for calculating a position from positioning signals transmitted by a plurality of GNSS transmitters. For example the receiver compsises a first and a second signal acquisition elements having different polarizations, the receiver being configured to process the signals received on the first signal acquisition element to calculate first pseudo range measurements, and the signals received on the second signal acquisition element to calculate second pseudo range measurements and associated quality indicators. The receiver further comprises a calculation circuit configured to select at least one of the second pseudo range measurements depending on the quality indicators, and compare it with the corresponding first pseudo range measurement, and select at least three first pseudo range measurements based on the comparison results to calculate a position.

Multipath mitigation in a GNSS radio receiver

The invention discloses an antenna assembly comprising one or more sensors, possibly a fish-eye camera which produces images of the sky above the antenna, said images being processed to identify open sky and occulted sky areas, said identification being used to generate an antenna gain pattern shape wherein null zones are placed on the occulted sky areas, so as to eliminate the GNSS signals which are affected by multipath reflection. The antenna assembly of the invention may be used with any GNSS receiver of the prior art. No specific data on the location of the receiver or its orientation is needed to perform the method of the invention, while in some embodiments, it may be useful to send some information on the number of satellites in view in the open sky.

Growing community of inventors

Muret, France

François-Xavier Marmet