Thales

Sextant Avionique

Bernard Fouilland

Nicolas Martin

Alain Renard

Christophe Gorecki

Vincent Maurice

Hervé Guichon

Rodolphe Boudot

Eric Kroemer

Patrick Vieux

The invention relates to a process for fabricating a microcell for a caesium atomic micro-clock having an inversion temperature above 80&#xb0; C., comprising a step of generating a caesium vapor by heating a caesium-containing pellet, the buffer gas used containing neon and helium.

Caesium atomic micro-clock microcell buffer gas mixture

This acquisition method is provided for acquiring a satellite signal emitted by a radio navigation satellite, the satellite signal containing a cyclic pseudo-random identification code specific to the satellite. The acquisition method includes the generation of a local code producing a replica of the identification code, and the production of a combined correlation (EDDC) of a received signal with the local code, the combined correlation corresponding to the linear combination of a first double delta correlation and of a second narrow correlation.

Method for acquiring a satellite radio navigation signal and satellite radio navigation receiver applying this method

A satellite-based positioning system reception device comprises a function for detecting false lock-ons based on a linear combination of complex signals arising from correlation pathways between a signal received from a satellite and a prompt local code and a plurality of local codes shifted by determined delays with respect to the prompt local code. An advantage is that the function for detecting false lock-ons makes it possible to remedy the false lock-ons due to multi-path phenomena.

Satellite-based positioning system reception device comprising a function for detecting false lock-ons

The disclosure pertains to receivers for positioning by satellite. To reduce the harmful effects of the paths reflected on the GPS measurement of position which should take account only of the path of the radiofrequency signals in direct line of sight, a method is proposed enabling the elimination of the influence of the multiple paths by simple extrapolation computation. Measurements are made by correlation with four pseudo-random codes E1, E2, L1, L2 that are replicas of a code received from a satellite. A first set of measurements of correlation energy values and of time received is carried out with the codes E1, L1 corresponding to an advance and a delay d with respect to a punctual code and a second set of measurements is carried out the codes E2, L2 corresponding to an advance and a delay k.d (k being different from 1 and 0). By linear extrapolation, a deduction is made therefrom of the measurements for k=0, which no corresponds to the case where the multiple paths have no effect. The disclosed method and circuit can be implemented with only one servo-control loop or with two independent loops.

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Fauconnieres, France

Bernard Fouilland