Abstract: A method and a device for the filtering of alerts originating from a collision detection system of an aircraft makes it possible, by proposing a novel condition for alert disabling, to avoid an abnormal drop of an aircraft in the case of a CFIT (controlled flight into terrain) by authorizing the output of the alert when this novel condition is not complied with. This novel condition relies on a method for thresholding the angle of approach of the aircraft (FPA for flight path angle) as a function of the altitude of the aircraft with respect to the runway and of the angle of approach specified for each runway and which is recovered via the terrain database.

Abstract: A method and a device for protecting an aircraft in the flight phase, said aircraft exhibiting several configurations of slats and flaps, comprises the following steps: determining, for at least one configuration of slats and flaps, of a limit angle of incidence beyond which the aircraft runs a risk of stalling, determining a gain factor as a function of the normal acceleration of the aircraft, comparing the current angle of incidence of the aircraft with the limit angle of incidence weighted by the gain factor, and, emission of an alert indicating that the aircraft runs a risk of stalling, if the current angle of incidence of the aircraft is greater than the limit angle of incidence weighted by the gain factor.

Abstract: A method and a device for the filtering of alerts originating from a collision detection system of an aircraft makes it possible, by proposing a novel condition for alert disabling, to avoid an abnormal drop of an aircraft in the case of a CFIT (controlled flight into terrain) by authorizing the output of the alert when this novel condition is not complied with. This novel condition relies on a method for thresholding the angle of approach of the aircraft (FPA for flight path angle) as a function of the altitude of the aircraft with respect to the runway and of the angle of approach specified for each runway and which is recovered via the terrain database.

Abstract: System for detecting wake turbulence (SDWT) of a first aircraft, which can be embedded onboard a second aircraft, comprising: first means (DET1) for determining the roll (Roll2) of the second aircraft; second determination means (DET2) of an envelope (CRollRef) of reference roll curves which is representative of a wake turbulence created by the first aircraft; means (COMP) for comparing, over a sliding window, the roll (Roll2) of the second aircraft and the envelope (CRollRef) of reference roll curves; and alarm means (AL) for forewarning the pilot of the second aircraft of the detection of wake turbulence of the first aircraft when the said comparison is below a resemblance threshold (SS).

Abstract: A method and a device for protecting an aircraft in the flight phase, said aircraft exhibiting several configurations of slats and flaps, comprises the following steps: determining, for at least one configuration of slats and flaps, of a limit angle of incidence beyond which the aircraft runs a risk of stalling, determining a gain factor as a function of the normal acceleration of the aircraft, comparing the current angle of incidence of the aircraft—with the limit angle of incidence weighted by the gain factor, and, emission of an alert indicating that the aircraft runs a risk of stalling, if the current angle of incidence of the aircraft is greater than the limit angle of incidence weighted by the gain factor.

Abstract: Method, device and item of equipment for filtering alarms originating from a windshear detection system embedded in an aircraft being able to emit an alarm. The aircraft has at least one sensor allowing the acquisition of a flight parameter. The device includes: units for the calculation of the second derivative of the flight parameter, units for the calculation of the absolute value of the second derivative of the flight parameter, units for the comparison of the absolute value of the second derivative of the flight parameter with a threshold C1, units for evaluating whether the absolute value of the second derivative of the flight parameter exceeds the threshold C1 over a duration greater than a time threshold T, and units for suppressing the alarm originating from the windshear detection system.

Abstract: System for detecting wake turbulence (SDWT) of a first aircraft, which can be embedded onboard a second aircraft, comprising: first means (DET1) for determining the roll (Roll2) of the second aircraft; second determination means (DET2) of an envelope (CRollRef) of reference roll curves which is representative of a wake turbulence created by the first aircraft; means (COMP) for comparing, over a sliding window, the roll (Roll2) of the second aircraft and the envelope (CRollRef) of reference roll curves; and alarm means (AL) for forewarning the pilot of the second aircraft of the detection of wake turbulence of the first aircraft when the said comparison is below a resemblance threshold (SS).

Abstract: The present invention relates to a frequency shifter in an optical path containing a pulsed laser source, and it is characterized in that it comprises at least one frequency shifter (12, 13) containing an optical propagation medium, the optical path length of which is modified according to the desired frequency shift during at least one pulse among n consecutive pulses from the laser, where n?1.

Abstract: The invention relates to a device for measuring a Doppler frequency shift, including an optical signal channel delivering a signal light beam illuminating a reference medium; and a reference channel delivering a reference light beam for detecting the Doppler frequency shift. The frequency shift is determined from the difference in frequency between the light signal illuminating the reference medium and the light beam returned by the reference medium. The device includes at least two light radiation sources, preferably lasers, with one light radiating source generating the light beam for the signal channel and the other source generating the light beam for the reference channel.

Abstract: The invention relates to a method, a device and an item of equipment for filtering alarms originating from a windshear detection system embedded in an aircraft being able to emit an alarm. The aircraft has at least one sensor allowing the acquisition of a flight parameter. The device according to the invention includes: means (302), (402) for the calculation of the second derivative of the flight parameter, means (303), (403) for the calculation of the absolute value of the second derivative of the flight parameter, means (304), (404) for the comparison of the absolute value of the second derivative of the flight parameter with a threshold C1, means for evaluating whether the absolute value of the second derivative of the flight parameter exceeds the threshold C1 over a duration greater than a time threshold T, and means for suppressing the alarm originating from the windshear detection system (350), (450).

Abstract: The present invention relates to a frequency shifter in an optical path containing a continuous laser source, and it comprises at least two frequency shift modules placed in parallel and each containing an optical propagation medium, the optical path length of which is modified according to the desired frequency shift, each of these modules being controlled separately, this shifter comprising a switch (14) which is connected to the outputs of these modules and is controlled so as to choose, at each instant, the module providing the desired frequency shift, the switch delivering, at its output, a continuous optical beam whose frequency is adjusted by contiguous sections.

Abstract: The invention relates to a Doppler frequency shift measuring device of the optical type comprising an optical signal channel delivering, through a polarization-splitting coupler, through a bidirectional signal port of the coupler, a signal light beam illuminating a reference medium, the coupler receiving, through said bidirectional port, a backscattered light beam returned by the reference medium; a reference channel providing a reference light beam for detection of the Doppler frequency shift, the frequency shift being determined by the frequency shift between the light signal illuminating the reference medium and the light beam returned by the reference medium. The reference light beam is applied to a reference port of the polarization-splitting coupler, said coupler delivering, at a port, a beat signal between the frequency of the reference light beam applied to the port and the frequency of the backscattered light beam applied to the port, possibly containing the Doppler shift.

Abstract: The invention relates to a device for remote measurement of the properties of the atmosphere, more particularly a device used to detect atmospheric turbulence. The device operates on the lidar principle, using the backscattering of a laser beam by the air. The device comprises a laser emission source (1), optical means (5) for collecting a backscattered beam (3) that is backscattered by targets illuminated by the emission source (1), the backscattered beam (3) being substantially centerd about the wavelength of the emission source (1), and means (9) for generating interference fringes (24) resulting from the backscattered beam (3). The device also includes a spatial filter (11) allowing only a central spot of the interference fringes to be seen and, at the center of the spatial filter (11), a mask for blocking off the center of the central spot and more particularly the Mie line of the backscattered beam.

Abstract: The invention relates to an optical measurement device designed notably to evaluate the velocity of an aircraft by detection of a Doppler shift. The device for measurement by optical probe comprises at least two light beams of different wavelengths ?1 , ?2, denoted as first beam and second beam, the device illuminating a reference medium MILREF (60) by the first beam and receiving a light echo Sr reflected back by the reference medium, and the device comprising: an optical coupler COUPL (70) receiving, on the one hand, the light echo Sr reflected back by the reference medium MILREF and, on the other, the second beam, the coupler delivering a resultant wave Or comprising the second beam and the light echo Sr; an optical amplification unit AMPLI (80), of bandwidth Bopt, receiving the resultant wave Or and delivering an amplified resultant wave Ora.

Abstract: The invention relates to a Doppler frequency shift measuring device of the optical type comprising an optical signal channel delivering, through a polarization-splitting coupler, through a bidirectional signal port of the coupler, a signal light beam illuminating a reference medium, the coupler receiving, through said bidirectional port, a backscattered light beam returned by the reference medium; a reference channel providing a reference light beam for detection of the Doppler frequency shift, the frequency shift being determined by the frequency shift between the light signal illuminating the reference medium and the light beam returned by the reference medium. The reference light beam is applied to a reference port of the polarization-splitting coupler, said coupler delivering, at a port, a beat signal between the frequency of the reference light beam applied to the port and the frequency of the backscattered light beam applied to the port, possibly containing the Doppler shift.

Abstract: The invention relates to a device for measuring a Doppler frequency shift, comprising: an optical signal channel (60) delivering a signal light beam illuminating a reference medium; a reference channel (80) delivering a reference light beam for detecting the Doppler frequency shift, the frequency shift being determined from the difference in frequency between the light signal illuminating the reference medium and the light beam returned by the reference medium, characterized in that it includes at least two light radiation sources (SL1, SL2), preferably lasers, one light radiating source generating the light beam for the signal channel and the other source generating the light beam for the reference channel.

Abstract: The present invention relates to a frequency shifter in an optical path containing a continuous laser source, and it comprises at least two frequency shift modules placed in parallel and each containing an optical propagation medium, the optical path length of which is modified according to the desired frequency shift, each of these modules being controlled separately, this shifter comprising a switch (14) which is connected to the outputs of these modules and is controlled so as to choose, at each instant, the module providing the desired frequency shift, the switch delivering, at its output, a continuous optical beam whose frequency is adjusted by contiguous sections.

Abstract: The present invention relates to a frequency shifter in an optical path containing a pulsed laser source, and it is characterized in that it comprises at least one frequency shifter (12, 13) containing an optical propagation medium, the optical path length of which is modified according to the desired frequency shift during at least one pulse among n consecutive pulses from the laser, where n?1.

Abstract: The invention relates to an optical measurement device designed notably to evaluate the velocity of an aircraft by detection of a Doppler shift. The device for measurement by optical probe comprises at least two light beams of different wavelengths ?1, ?2, denoted as first beam and second beam, the device illuminating a reference medium MILREF (60) by the first beam and receiving a light echo Sr reflected back by the reference medium, and the device comprising: an optical coupler COUPL (70) receiving, on the one hand, the light echo Sr reflected back by the reference medium MILREF and, on the other, the second beam, the coupler delivering a resultant wave Or comprising the second beam and the light echo Sr; an optical amplification unit AMPLI (80), of bandwidth Bopt, receiving the resultant wave Or and delivering an amplified resultant wave Ora.

Abstract: The invention relates to a device for remote measurement of the properties of the atmosphere, more particularly a device used to detect atmospheric turbulence. The device operates on the lidar principle, using the backscattering of a laser beam by the air. The device comprises a laser emission source (1), optical means (5) for collecting a backscattered beam (3) that is backscattered by targets illuminated by the emission source (1), the backscattered beam (3) being substantially centred about the wavelength of the emission source (1), and means (9) for generating interference fringes (24) resulting from the backscattered beam (3). The device also includes a spatial filter (11) allowing only a central spot of the interference fringes to be seen and, at the centre of the spatial filter (11), a mask for blocking off the centre of the central spot and more particularly the Mie line of the backscattered beam.