Abstract: The present invention relates to a method for locating an aircraft (Ak), the said aircraft (Ak) being equipped with at least one device for sending and receiving ADS-B signals, a set of ADS-B communication beacons being deployed on the ground, the position of each of the said ADS-B beacons being known, the said locating method comprising: a step of calibrating the time biases of the ADS-B beacons with a view to correcting the synchronization discrepancies when sending, by means of the calculation of the time discrepancy existing between the ADS-B beacons (B1, B2) upon reception of downgoing ADS-B signals sent by a set of aircraft equipped with at least one device for sending ADS-B signals; a step of calculating the pseudo-distances between the said aircraft (Ak) and the said ADS-B beacons deployed on the ground, on the basis of the upgoing ADS-B signals.

Abstract: A method of detecting interference in a satellite radio-navigation signal, calculates an item of information representative of the slope of the correlation function correlating the said signal with a local spreading code. The correlation function has substantially the theoretical form of an isosceles triangle, with the slope being estimated on any one of the equal-length sides of the isosceles triangle. The method further includes comparing the item of information with a detection threshold configured at least as a function of a target signal-to-noise ratio.

Abstract: A method for compressing a wide band satellite radio-navigation signal is disclosed. The wide band signal is compressed in order to transmit it on a narrow band channel. A correlation function is calculated for the spreading code of the compressed satellite radio-navigation signal.

Abstract: Method of detecting interference in a satellite radio-navigation signal determines the temporal position for which the correlation between the signal and a local spreading code offset by the position is maximum, calculating an information item representative of the intercorrelation between a first measurement of the correlation of the signal with a local spreading code at a first temporal position advanced relative to the temporal position of the maximum by a duration greater than the duration of a slot of the spreading code and a second measurement of the correlation of the signal with a local spreading code at a second temporal position delayed relative to the temporal position of the maximum by a duration greater than the duration of a slot of the spreading code, and comparing the item with a detection threshold configured at least as a function of the ratio of the powers of the signal and of the interference.

Abstract: Method of detecting interference in a satellite radio-navigation signal, characterized in that it comprises the following steps: Calculating an item of information representative of the slope of the correlation function correlating the said signal with a local spreading code, the said correlation function having substantially the theoretical form of an isosceles triangle, the said slope being estimated on any one of the equal-length sides of the said isosceles triangle; and Comparing the said item of information with a detection threshold configured at least as a function of a target signal-to-noise ratio.

Abstract: Method of detecting interference in a satellite radio-navigation signal, characterized in that it comprises the following steps: determining a first temporal position for which the correlation between the said signal and a local spreading code, offset by the said position, is maximum; determining a plurality of measurements of correlation between the said signal and a local spreading code offset by a plurality of secondary temporal positions, the said plurality of secondary temporal positions and the said first temporal position being regularly spaced; determining, for a plurality of correlation measurement pairs formed by two measurements at two consecutive temporal positions, the phase difference between the two correlation measurements of the said pair; calculating an item of information representative of the standard deviation of the said phase difference; and comparing the said item of information with a detection threshold configured at least as a function of the ratio of the powers of the signal and

Abstract: Station for receiving satellite radio navigation signals having first wideband transmission means that are suited to receiving a specific signal transmitted by a transmitter/receiver and extracting therefrom at least one user radio navigation signal, first centralized signal processing means that are suited to determining a measurement of pseudo distance and centralized calculation means for calculating navigation information (PVT), the reception station having a first reference channel for receiving radio navigation signals having a directional antenna for forming a channel, second means for processing the radio navigation signal received by said directional antenna for forming a channel and a calculation unit that is suited to performing an improvement in reliability, an integrity check and authentication of said navigation information (PVT).

Abstract: Dual-frequency receiver for satellite-based positioning, comprising a main measurement channel and a secondary channel for a calculation for correction of ionospheric propagation robust to differential errors linked to the local reception environment of the signals. Each channel comprises a code generator, a carrier phase generator, integrators, phase and code discriminators, a code phase numerically-controlled oscillator, a carrier phase numerically-controlled oscillator, carrier phase loop matched filtering means, and code phase loop matched filtering means. The receiver further including: means for determining the respective phase errors in the main and secondary channels comprising means of interspectral correlation of the signals of the main and secondary channels already correlated by the local code, after frequency compensation of the relative Doppler shifts of the signals; and respective feedback loops for the code and carrier phase errors in the main and secondary channels.

Abstract: The invention relates to a method for compressing a wide band satellite radio-navigation signal in order to transmit it on a narrow band channel and to a method for calculating the correlation function of the spreading code of a satellite radio-navigation signal compressed by application of the compression method.

Abstract: Method for determining navigation parameters of an aircraft, characterized in that it consists at least in determining the geographic speed {right arrow over (V)}, expressed in a given local fixed coordinate system {{right arrow over (i)}, {right arrow over (j)}, {right arrow over (k)}}, based on the measurements m, of carrier phase increments ??i of the radio navigation signals originating from a plurality of radio navigation satellites in sight of said aircraft, each of said measurements mi constituting an estimate of the relative speed of said aircraft relative to said satellite projected onto the sight axis linking the aircraft to the satellite, each of said measurements m, being compensated by the apparent radial speed of the satellite.

Abstract: The present invention relates to a device for eliminating the perturbation signals received by a reference GNSS station. The device has means for receiving a signal of interest that is transmitted via a satellite. It likewise has means for receiving the perturbation signals, said means including means for receiving said perturbation signals that are isolated from the signal of interest. It also has means for subtracting the perturbation signals from the signal of interest, said means including means for estimating the differential transfer function W between the reception channel for the signal of interest and the reception channel for the perturbation signals, so as to perform coherent subtraction of said signals.

Abstract: An inertial system measures the attitude of an aircraft consisting at least in determining the angle of pitch and/or the angle of heading and/or the angle of roll of the aircraft, each of the said angles of attitude being determined by successive double integration of their second derivative. A pair of accelerometers to determine the angle of pitch being are disposed on either side of the centre of gravity along an axis substantially merged with the longitudinal axis of the aircraft. A pair of accelerometers to determine the angle of heading are disposed on either side of the centre of gravity along an axis substantially merged with the transverse axis of the aircraft. A pair of accelerometers to determine the angle of roll are disposed on either side of the centre of gravity along a vertical axis perpendicular to the plane formed by the other axes.

Abstract: A receiver of satellite signals serving for location (GNSS) adapted to be fixed on a support comprising at least one antenna able to receive the said satellite signals serving for location, the antenna comprising at least two mobile phase centres, determination means for determining a location on the basis of the said satellite signals received, comprises displacement means adapted for displacing the said phase centres, for selecting one of the phase centres and for determining a position of the said selected phase centre with respect to the support.

Abstract: Automatic gain control device for satellite positioning receivers characterized in that it comprises means for estimating the temporal occupancy rate of the pulses within the useful band, closed-loop control of the automatic gain control being applied in an optimal manner as a function of the said temporal occupancy rate, in such a manner as to reduce the influence of the pulsed interference within the band and out-of-band; notably, an AGC decision module returns a control signal for the attention of a non-linear function module applying a given weighting to the signals resulting from a comparison between the power or the amplitude of digitized input signals and a setpoint threshold value CAGC.

Abstract: The present invention relates to a method for locating an aircraft (Ak), the said aircraft (Ak) being equipped with at least one device for sending and receiving ADS-B signals, a set of ADS-B communication beacons being deployed on the ground, the position of each of the said ADS-B beacons being known, the said locating method comprising: a step of calibrating the time biases of the ADS-B beacons with a view to correcting the synchronization discrepancies when sending, by means of the calculation of the time discrepancy existing between the ADS-B beacons (B1, B2) upon reception of downgoing ADS-B signals sent by a set of aircraft equipped with at least one device for sending ADS-B signals; a step of calculating the pseudo-distances between the said aircraft (Ak) and the said ADS-B beacons deployed on the ground, on the basis of the upgoing ADS-B signals.

Abstract: Dual-frequency (L1, L2) receiver for satellite-based positioning, comprising a main measurement channel (L1) and a secondary channel (L2) for a calculation for correction of ionospheric propagation robust to differential errors linked to the local reception environment of the signals, each channel comprising a code generator, a carrier phase generator, integrators, phase and code discriminators, a code phase numerically-controlled oscillator (NCOC), a carrier phase numerically-controlled oscillator (NCOP), carrier phase loop matched filtering means, and code phase loop matched filtering means, comprising, furthermore: means for determining the respective phase errors in the main and secondary channels comprising means of interspectral correlation (INT3, M3) of the signals of the main and secondary channels (L1, L2) already correlated by the local code, after frequency compensation of the relative Doppler shifts of the said signals; and respective feedback loops (B1, B2) for the code and carrier phase error

Abstract: Automatic gain control device for satellite positioning receivers characterized in that it comprises means for estimating the temporal occupancy rate of the pulses within the useful band, closed-loop control of the automatic gain control being applied in an optimal manner as a function of the said temporal occupancy rate, in such a manner as to reduce the influence of the pulsed interference within the band and out-of-band; notably, an AGC decision module (6004) returns a control signal for the attention of a non-linear function module (6006) applying a given weighting to the signals resulting from a comparison between the power or the amplitude of digitized input signals and a setpoint threshold value CAGC (6005).

Abstract: An inertial system measures the attitude of an aircraft consisting at least in determining the angle of pitch and/or the angle of heading and/or the angle of roll of the aircraft, each of the said angles of attitude being determined by successive double integration of their second derivative. A pair of accelerometers to determine the angle of pitch being are disposed on either side of the centre of gravity along an axis substantially merged with the longitudinal axis of the aircraft. A pair of accelerometers to determine the angle of heading are disposed on either side of the centre of gravity along an axis substantially merged with the transverse axis of the aircraft. A pair of accelerometers to determine the angle of roll are disposed on either side of the centre of gravity along a vertical axis perpendicular to the plane formed by the other axes.

Abstract: Method for determining navigation parameters of an aircraft, characterized in that it consists at least in determining the geographic speed {right arrow over (V)}, expressed in a given local fixed coordinate system {{right arrow over (i)}, {right arrow over (j)}, {right arrow over (k)}}, based on the measurements m, of carrier phase increments ??i of the radio navigation signals originating from a plurality of radio navigation satellites in sight of said aircraft, each of said measurements mi constituting an estimate of the relative speed of said aircraft relative to said satellite projected onto the sight axis linking the aircraft to the satellite, each of said measurements m, being compensated by the apparent radial speed of the satellite.

Abstract: A synthetic aperture antenna device for transmitting signals of a system includes a carrier and means for determining its trajectory, and, for each signal respectively associated with a spatial direction, processing means suitable for generating a stationary phase signal over a time window corresponding to the distance traveled by the device throughout the period of coherent integration, before modulation of the received signal, the processing means comprising correction means suitable for correcting the carrier phase of the signal.