Thales

Christian Mehlen

Jacques Coatantiec

Nicolas Martin

Pierre-Yves Dumas

David Depraz

Denis Bouvet

Nicolas Vercier

Roland Frenkiel

Jean-Baptiste Thevenet

Estelle Pierre

Emmanuel Nguyen

Muhammed Halep

Philippe Laviron

A GNSS signal multipath detection device () for a GNSS receiver () on-board a carrier further comprising one or a plurality of antennas () and comprising:

GNSS signal multipath detection device, and associated carrier geolocation system and multipath detection method

A method for detecting masking of one or more satellites by an obstacle for a GNSS receiver on board a movable carrier, including receiving, for each one of M satellites, a code pseudo-distance measurement and a variation of carrier pseudo-distances, computing of a definite position of the receiver and a computed position of each satellite, detecting a masking of at least one satellite on the basis of the following operations: computing, at a computation instant and for each satellite, of a computed pseudo-distance and a pseudo-distance reconstructed at a previous time, and detecting masking of at least one satellite by analyzing a magnitude, called residue, computed by applying a least squares algorithm.

Method for detecting masking of one or more satellites, electronic detection device and associated computer program product

This detection method is carried out after a phase for acquiring a navigation signal during a convergence phase and comprises at least one of the following steps: &#x2014;determining a plurality of pilot channel periodic correlations and a plurality of data channel periodic correlations, and determining a first value as a function of these periodic correlations; &#x2014;determining a plurality of pilot channel partial correlations, and determining a second value as a function of these partial correlations; &#x2014;determining a plurality of shifted pilot channel correlations, and determining a third value as a function of these shifted pilot channel correlations. The convergence phase further comprises the step for determining a wrong synchronization when at least one of the first value, the second value, and the third value exceeds a predetermined threshold.

Detection method of a wrong synchronization of a receiver with a satellite, associated receiver and computer program product

This method for determining a virtual speed vector includes the steps of acquiring () a sequences of images of the surrounding environment from an image sensor defining an optical projection center that is substantially stationary relative to the mobile engine, analyzing () at least two successive images in order to determine, in each of the two images, a point, called epipole, representing the position in said image of the optical center of the image sensor at the moment of the acquisition of the other image, and for each analyzed image, determining () the position of the epipole of said image on a display usable to pilot the mobile engine and displaying (), on the display, a symbol representative of the virtual speed vector in said position.

Determining method of a virtual velocity vector of a mobile engine, associated computer program product and determining system

A method of calculating a speed of an aircraft, a method for calculating a protection radius, a positioning system and an associated aircraft are disclosed. In one aspect, the method includes obtaining a measured speed of the aircraft and obtaining a measured position of the aircraft, associated with a reliability protection radius related to position. The method also includes calculating, by a correction loop, a corrected speed, wherein the calculation of the corrected speed includes calculating a calculated position by integration of the corrected speed, and correcting the measured speed as a function of a difference between the calculated position and the measured position. The method further comprising calculating a reliability protection radius related to the corrected speed.

Method for calculating a speed of an aircraft, method for calculating a protection radius, positioning system and associated aircraft

A system comprises: onboard a first craft, called host craft, a triplet of antennas comprising a transmitting and receiving antenna and two transmitting antennas, a transmission chain that can be successively coupled to each antenna of the triplet of antennas by a radiofrequency switch, a reception chain that can be coupled to the transmitting and receiving antenna, and a processing device intended to determine a relative angular position between, on the one hand, the host craft and, on the other hand, a plurality of spacecraft, called companion craft, from measurements of path differences performed and transmitted by the companion craft; onboard the companion craft, a transmitting and receiving antenna, a transmission chain and a reception chain coupled to the transmitting and receiving antenna and a measurement device intended to measure path differences between three signals originating from the three antennas of the triplet of antennas of the host craft.

Radiofrequency method and system for determining, by pairs of spacecraft, the relative angular position between a plurality of remote spacecraft

Estimating the speed of an aircraft estimates three components of the speed vector (TAS, AOA, SSA) of an aircraft relative to the surrounding air. The static pressure is estimated on the basis of measurements of geographical altitude. A first intermediate variation of a linear combination of the three components of the speed vector of the aircraft relative to the surrounding air is estimated using explicitly the fact that the pressure measured by the static probe is falsified by a known quantity under the effect of the three components of this speed vector of the aircraft relative to the surrounding air. The process then estimates the three components of the speed vector of the aircraft relative to the air by likening the latter to the speed vector of the aircraft relative to an inertial reference frame and by using inertial measurements. The various estimates are fused to provide a final result.

Method of estimation of the speed of an aircraft relative to the surrounding air, and associated system

Method of estimation of the speed of an aircraft relative to the surrounding air, in a reference frame tied to the aircraft estimates an estimated static pressure on the basis of measurements of geographical altitude. The process then estimates a first intermediate variation of the speed of the aircraft relative to the surrounding air using explicitly the fact that the pressure measured by the static probe is falsified by a known quantity under the effect of the speed of the aircraft relative to the surrounding air. Finally, temporal integration of the first intermediate variation of the speed of the aircraft relative to the surrounding air provides an estimated speed of the aircraft relative to the surrounding air.

A control device (D), for a spacecraft (S) of a group of spacecraft moving in formation, comprises i) an assembly consisting of three antennas (A-A) installed on a face of the spacecraft (S) and capable of emitting and/or receiving first and second RF signals exhibiting first and second frequencies spaced apart by a chosen frequency gap, ii) first measurement means (M) charged with determining first and second differences in path length between antennas (A-A), corresponding to the first frequency and to the frequency gap, on the basis of the first and second signals received by the antennas and originating from another spacecraft, iii) second measurement means (M) charged with delivering measurements of rotation undergone by the spacecraft (S), and iv) processing means (MT) a) charged with coarsely estimating the direction of transmission of the signals received on the basis of first and second initial path length differences, b) with ordering the positioning of the spacecraft (S) so that a chosen axis of a frame of reference tied to said spacecraft is aligned with respect to the coarse direction of transmission, c) with ordering the rotational turning of the spacecraft (S) about the chosen axis, d) with precisely estimating the direction of transmission of the signals emitted by the other spacecraft (Si') on the basis of the rotation measurement and of a measurement of variation of the first path length difference induced by this rotation.

Device for controlling relative position(s) by analyzing dual-frequency signals, for a spacecraft of a group of spacecraft in formation

A control device (D) for a spacecraft of a group of spacecraft intended to travel in a chosen formation comprises i) a set of at least three send/receive antennas (A-A) installed on at least three differently oriented faces of its spacecraft and adapted to send/receive radio-frequency signals, ii) first measuring means (M) responsible for determining the power of the signals received by each of the antennas (A-A) and for delivering sets of powers each associated with one of the other spacecraft of the group, iii) storage means (BD) responsible for storing sets of cartographic data each representative of the normalized powers of the signals received by each of the antennas (A-A) as a function of chosen send directions, and iv) processor means (MT) responsible for comparing each set of powers delivered by the first measuring means (M) to the stored sets of cartographic data in order to estimate each send direction of the signals sent by the other spacecraft of the group with respect to a system of axes fixed with respect to their spacecraft.

Growing community of inventors

Etoile sur Rhone, France

Christian Mehlen