Thales

Sextant Avionique

Patrice Guillard

Alain Renard

Sébastien Legoll

Nicolas Martin

Jacques Coatantiec

David Depraz

Jean-Luc Sicre

The general field of the invention is that of resonating or vibrating devices. One of the tricky points with this type of device is that of correctly measuring the vibration frequency in a disturbed environment. The analysis system according to the invention is based on the use of the Hilbert transform of a function U representative of the position A of the vibrations of the device. More precisely, in its basic version, the analysis system comprises means making it possible to realize the second derivative of the function U denoted U, the Hilbert transform of the function U denoted V, the second derivative of this transform denoted Vas well as a function equal to this latter function being mathematically equal to the function with &#x3c9;the instantaneous angular frequency of U, &#x3c1;the instantaneous amplitude of U, &#x3c1;the second derivative of said instantaneous amplitude and being representative of the square of the resonant angular frequency &#x3a9; of the vibrating device. Several variants of this initial device are proposed.

System for analysing the frequency of resonating devices

Described is a device for receiving radio-navigation signals by satellite, said received signals being transmitted at a carrier frequency. The device includes at least means for generating a local signal at a local frequency and a tracking device including a feedback loop called carrier loop for phase-locking the local frequency on the carrier frequency. The loop includes a hardware portion and a software portion. The software portion performs the functions of discrimination of the phase of the correlated signal and filtering of said phase. The software portion also includes correlation functions mainly dependent on the linear variation coefficients between the local phases &#x3c6;delivered after each basic computation cycle. The device makes it possible to increase the loop band and the dynamic stability without changing the pre-detection band and the workload of the software.

Device for receiving satellite signals including a phase loop with delay compensation

A signal measurement and processing device includes two systems allowing a signal and its opposite to be simultaneously received at the input and two signals able to take polynomial form, as a function of the input signals, to be returned. The device includes means for performing a weighted sum and difference of the two output signals in such a manner that at least the weighted sum is independent to a first order of the variations in the input signals. This processing operation is particularly well adapted to systems subjected to spurious effects such as thermal drifts.

Signal processing device for systems in differential configuration

The invention relates to an internal platform hybridized with a GPS receiver. The hybridization is achieved through a Kalman filter through which a new hybrid position D-HYB is estimated on the basis of a noted deviation between pseudo-distance measure by the receiver between the receiver and the various satellites and corresponding distances computed by the inertial platform between the platform and the same satellites. In this filtering, the distance increment from one measurement instant to the next instant, between the pseudo-distance previously measured by the receiver on a satellite axis of a deviation and the new pseudo-distance measured by the receiver on a satellite axis of a deviation and the new pseudo-distance measured by the receiver on this axis, is the phase variation &#x394;&#x3a6;=&#x3a6;(t)&#x2212;&#x3a6;I (t&#x2212;1) of a digital oscillator between the two measurement instants, this variation being referred to distance along the satellite axis. The oscillator is that which makes it possible to slave the local carrier frequency in the receiver to the carrier frequency received from the satellite. Application to the measurement of position.

Hybrid inertial navigation system with improved integrity

Aircraft piloting aid system using a head-up display

Method of air navigation assistance for guiding a moving vehicle towards

Receiver for determining a position on the basis of satellite networks

This receiver comprises a signal processor using the correlation of the received composite signal with early/late, locally generated pseudo-random codes. The code generator sends its signals to a delay line whose evenly spaced out outputs (E2, E1, P, L1, L2) are combined according to the relationship:

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Valence, France

Patrice Guillard