Abstract: 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.

Abstract: 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 ?local 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.

Abstract: 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.

Abstract: The general field of the invention is that of devices for receiving radio-navigation signals by satellite, said received signals being transmitted at a carrier frequency, said device including 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, said loop including 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. In the various devices according to the invention, the software portion also includes correlation functions mainly dependent on the linear variation coefficients between the local phases ?local delivered after each basic computation cycle. The proposed 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.

Abstract: The general field of the invention is that of signal measurement and processing devices comprising 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 according to the invention comprises 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.

Abstract: 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.

Abstract: 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 ??=?(t)??I (t?1) of a digital oscillator between the two measurement instants, this variation being referred to distance along the satellite axis.

Abstract: The invention relates to an inertial system hybridised with a GPS receiver. Said hybridisation is carried out by Kalman filtering, by means of which is a new hybrid position D HYB is estimated from a deviation observed (Yo) between (i) pseudo-distances measure by the receiver between the receiver and the different satellites and (ii) the corresponding distances calculated by the inertial system between the system and the same satellites. In the aforementioned filtering, the distance increment from one measuring time to the next, between (i) the pseudo-distance previously measured by the receiver on a satellite axis in order to observe a deviation and (ii) the new pseudo-distance measured by the receiver on said axis, is the phase variation &Dgr;&PHgr;=&PHgr;i(t)−&PHgr;i(t-1) of a digital oscillator between the two measuring times, said variation being brought along the length of the satellite axis in terms of distance.

Abstract: The invention relates to systems for aiding the piloting of aircraft, mainly for take-off and landing under poor conditions of visibility.In order to benefit from the contribution of head-up displays, which exhibit symbols for the artificial horizon line, aircraft longitudinal attitude and ground speed vector, without using an IRS inertial unit to supply the heading and attitude information, it is proposed to use a non-inertial AHRS unit associated with a compass, and periodically to correct the information which it supplies, in order to exhibit the attitude symbols with the aid of the corrected information rather than the raw information from the AHRS unit. The correction is given by two GPS receivers (GPS1, GPS2) associated with antennas (A1, A2) on the top of the aircraft, an interferometric measurement of radiofrequency carrier phase being made to determine a direction vector of the aircraft.

Abstract: A method of air navigation for guiding a moving vehicle toward a moving target. Both the moving vehicle and the moving target use satellite positioning receivers. Instead of transmitting the position computed by the target to the vehicle, only the pseudo-range and pseudo-velocity measurements between the target and the satellites are transmitted by radio to the vehicle. The pseudo-range, pseudo-velocity and measuring time measurements of the moving vehicle are carried out. The vehicle then determines the satellites used by both the vehicle and target. The target then subtracts for each of the satellites the pseudo-range and pseudo-velocity measurements determined by the vehicle from those received by the target and computes on the basis of these answers, relative speed vectors between the vehicle and the target. This is particularly useful for airplanes or helicopters landing on the decks of ships, a rendezvous in the air, at sea or in space and homing vehicles onto a marker.

Abstract: A receiver for determining position based on GPS satellites and GLONASS satellites. The receiver architecture includes a radio reception chain with an antenna, frequency conversion circuits, an analogue/digital converter operating at very high rate for the GLONASS pathway, and a signal processing circuit with several general-use channels capable of receiving both GPS signals and GLONASS signals. This circuit uses a programmable pseudo-random code generator and a phase servocontrol loop which uses a local oscillator to produce a local transposed carrier frequency; this oscillator is controlled in such a way as to be able to impose a start frequency for the acquisition of a satellite signal.

Abstract: 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:c=E2-2E1+2L1-L2before being sent to one of the correlators (C2) while the other (C1) receives the punctual signal (P). This especially reduces the positional error due to the multiple-path delays.