Abstract: Disclosed is a positioning system including: several inertial measurement units; at least one common sensor, providing a measurement of a positioning parameter of a system; for each inertial measurement unit, a navigation filter configured to: a) determine an estimate of the positioning parameter, on the basis of an inertial signal provided by the inertial measurement unit; and to b) correct the estimate, as a function of the measurement and of a correction gain that is determined on the basis of an augmented variance higher than the variance of a measurement noise of a common sensor; and—at least one fusion module determining a mean of the estimates, the mean being not reinjected at the input of the navigation filters. Also disclosed is an associated positioning method.

Abstract: Disclosed is a bathymetric system including a multi-beam emitting and receiving device attached to a carrier vehicle, configured, in a first recurrence, to measure the amplitude of a first plurality of beams reflected off the seabed, and a computer to determine three-dimensional spatial coordinates of a first scan swath. In a second recurrence, the device emits a second incident beam and measures the amplitude of a second plurality of beams reflected off the seabed, the computer determines the three-dimensional spatial coordinates of a second scan swath, so that at least one probe point of the first scan swath is redundant with a probe point of the second scan swath, and the computer calculates an altitude variation of the carrier vehicle using altitude variations of the at least one redundant probe point between the first recurrence and the second recurrence.

Abstract: Disclosed is a hybrid inertial measurement system including a cold atom interferometric inertial sensor having a laser source generating a sequence of laser pulses towards a cold atom burst and a conventional inertial sensor attached to the inertial reference frame of the interferometric inertial sensor. The hybrid system includes a signal processing system suitable for receiving an inertial measurement signal from the conventional inertial sensor and for generating in real time a non-linear frequency modulation signal, the feedback loop electronic system being configured to modulate in real time the central optical frequency of the laser according to the modulation signal, such that the cold atom interferometric inertial sensor generates a first hybrid inertial measurement signal by atomic interferometry corrected for the relative movements of the inertial reference frame.

Abstract: Disclosed is a bathymetric system including a multi-beam emitting and receiving device attached to a carrier vehicle, configured, in a first recurrence, to measure the amplitude of a first plurality of beams reflected off the seabed, and a computer to determine three-dimensional spatial coordinates of a first scan swath. In a second recurrence, the device emits a second incident beam and measures the amplitude of a second plurality of beams reflected off the seabed, the computer determines the three-dimensional spatial coordinates of a second scan swath, so that at least one probe point of the first scan swath is redundant with a probe point of the second scan swath, and the computer calculates an altitude variation of the carrier vehicle using altitude variations of the at least one redundant probe point between the first recurrence and the second recurrence.

Abstract: Disclosed is a positioning system including: several inertial measurement units; at least one common sensor, providing a measurement of a positioning parameter of a system; for each inertial measurement unit, a navigation filter configured to: a) determine an estimate of the positioning parameter, on the basis of an inertial signal provided by the inertial measurement unit; and to b) correct the estimate, as a function of the measurement and of a correction gain that is determined on the basis of an augmented variance higher than the variance of a measurement noise of a common sensor; and —at least one fusion module determining a mean of the estimates, the mean being not reinjected at the input of the navigation filters. Also disclosed is an associated positioning method.

Abstract: Disclosed is a hybrid inertial measurement system including a cold atom interferometric inertial sensor having a laser source generating a sequence of laser pulses towards a cold atom burst and a conventional inertial sensor attached to the inertial reference frame of the interferometric inertial sensor. The hybrid system includes a signal processing system suitable for receiving an inertial measurement signal from the conventional inertial sensor and for generating in real time a non-linear frequency modulation signal, the feedback loop electronic system being configured to modulate in real time the central optical frequency of the laser according to the modulation signal, such that the cold atom interferometric inertial sensor generates a first hybrid inertial measurement signal by atomic interferometry corrected for the relative movements of the inertial reference frame.

Abstract: A system and a method for the navigation of a mobile vehicle, suitable for determining and displaying a safe navigation zone for the mobile vehicle. The navigation system includes a dead reckoning navigation system (10), a calculator (50), a storage memory (60), an embedded sensor (20), and an electronic mapping system (70). The calculator (50) is suitable for calculating an estimated position of the mobile vehicle from speed and/or acceleration measurements and a comparison of the measurement of an environmental parameter with a geographical database. The calculator (50) is suitable for calculating the probability density of the presence of the mobile vehicle around each point on the map in order to deduce a safety zone (12) corresponding to a presence probability higher than, or equal to, a pre-determined threshold p.

Abstract: A system and a method for the navigation of a mobile vehicle, suitable for determining and displaying a safe navigation zone for the mobile vehicle. The navigation system includes a dead reckoning navigation system (10), a calculator (50), a storage memory (60), an embedded sensor (20), and an electronic mapping system (70). The calculator (50) is suitable for calculating an estimated position of the mobile vehicle from speed and/or acceleration measurements and a comparison of the measurement of an environmental parameter with a geographical database. The calculator (50) is suitable for calculating the probability density of the presence of the mobile vehicle around each point on the map in order to deduce a safety zone (12) corresponding to a presence probability higher than, or equal to, a pre-determined threshold p.

Abstract: An acoustic positioning device includes an acoustic emitter and receiver. The device emits a sequence of at least one first acoustic signal (S1) and one second acoustic signal (S2), separated by a time interval T, and to receive and measure the arrival phase ?1 of S1 and the arrival phase ?2 of S2. The device measures a relative displacement between the acoustic emitter and the acoustic receiver and determines the approximate difference (R2?R1)AUX between the distance R1 traveled by S1 between the acoustic emitter and receiver, and the distance R2 traveled by S2 between the acoustic emitter and the acoustic receiver, and calculates the relative displacement (R2?R1) between the acoustic emitter and the acoustic receiver as a function of the approximate difference (R2?R1)AUX, of the time interval T and of the arrival phases ?1, ?2 respectively of S1 and of S2.

Abstract: A hybrid navigation device includes at least one auxiliary sensor adapted to deliver at least one auxiliary signal and a plurality of hybrid navigation systems, each including at least one inertial navigation system and one calculator configured to form an hybrid signal at the output of each hybrid navigation system. The hybrid navigation device includes a module for the detection of good operating condition and the weighting of the hybrid navigation systems, the module being configured to receive the at least one auxiliary signal, and the hybrid signals of each hybrid navigation system, respectively, to deduce therefrom an indicator of good operating condition and a weighting coefficient for each hybrid navigation system, and to calculate a weighted hybrid signal as a function of the hybrid signals and of the weighting coefficients of each hybrid navigation system, respectively.

Abstract: An acoustic positioning device includes an acoustic emitter and receiver. The device emits a sequence of at least one first acoustic signal (S1) and one second acoustic signal (S2), separated by a time interval T, and to receive and measure the arrival phase ?1 of S1 and the arrival phase ?2 of S2. The device measures a relative displacement between the acoustic emitter and the acoustic receiver and determines the approximate difference (R2?R1)AUX between the distance R1 travelled by S1 between the acoustic emitter and receiver, and the distance R2 travelled by S2 between the acoustic emitter and the acoustic receiver, and calculates the relative displacement (R2?R1) between the acoustic emitter and the acoustic receiver as a function of the approximate difference (R2?R1)AUX, of the time interval T and of the arrival phases ?1, ?2 respectively of S1 and of S2.

Abstract: A positioning system has at least one underwater apparatus, which includes an acoustic receiver and a computer. The system includes a base station placed in the sea environment, the base station transmitting an acoustic signal received by the acoustic receiver, wherein the acoustic receiver includes a hydrophone, the base station includes at least two acoustic transmitters forming an antenna, the distances between the acoustic transmitters of the antenna being known and the transmitters being synchronized therebetween. According to the invention, the computer includes an element for calculating differences in arrival time and differences in phases of acoustic signals coming from the base station transmitters, and an element for calculating the possible geometric loci of the position of the apparatus relative to the base station and to the orientation thereof, and the position of the underwater apparatus is predetermined from these possible geometric loci.

Abstract: A hybrid navigation device includes at least one auxiliary sensor adapted to deliver at least one auxiliary signal and a plurality of hybrid navigation systems, each including at least one inertial navigation system and one calculator configured to form an hybrid signal at the output of each hybrid navigation system. The hybrid navigation device includes a module for the detection of good operating condition and the weighting of the hybrid navigation systems, the module being configured to receive the at least one auxiliary signal, and the hybrid signals of each hybrid navigation system, respectively, to deduce therefrom an indicator of good operating condition and a weighting coefficient for each hybrid navigation system, and to calculate a weighted hybrid signal as a function of the hybrid signals and of the weighting coefficients of each hybrid navigation system, respectively.

Abstract: A synthetic antenna sonar system, includes: a sonar provided with emission elements and reception elements, the reception elements including a composite physical antenna having N transducers, the sonar being located on a mobile carrier; an inertial unit arranged on the carrier and suitable for measuring instantaneous position and orientation informations of the carrier; a common clock supplying a temporal signal enabling the synchronization of both the inertial unit and the sonar; elements for determining the instantaneous speed of the carrier, the determined speed feeding the inertial unit to correct the drift thereof; and micronavigation elements enabling an image of the seafloor to be obtained through formation of the synthetic antenna channels from K sonar operation recurrences, considering that the physical antenna movement during the carrier displacement is fully known from the informations measured by the inertial unit.

Abstract: A positioning system has at least one underwater apparatus, which includes an acoustic receiver and a computer. The system includes a base station placed in the sea environment, the base station transmitting an acoustic signal received by the acoustic receiver, wherein the acoustic receiver includes a hydrophone, the base station includes at least two acoustic transmitters forming an antenna, the distances between the acoustic transmitters of the antenna being known and the transmitters being synchronized therebetween. According to the invention, the computer includes an element for calculating differences in arrival time and differences in phases of acoustic signals coming from the base station transmitters, and an element for calculating the possible geometric loci of the position of the apparatus relative to the base station and to the orientation thereof, and the position of the underwater apparatus is predetermined from these possible geometric loci.

Abstract: A synthetic antenna sonar system, includes: a sonar provided with emission elements and reception elements, the reception elements including a composite physical antenna having N transducers, the sonar being located on a mobile carrier; an inertial unit arranged on the carrier and suitable for measuring instantaneous position and orientation informations of the carrier; a common clock supplying a temporal signal enabling the synchronization of both the inertial unit and the sonar; elements for determining the instantaneous speed of the carrier, the determined speed feeding the inertial unit to correct the draft thereof; and micronavigation elements enabling an image of the seafloor to be obtained through formation of the synthetic antenna channels from K sonar operation recurrences, considering that the physical antenna movement during the carrier displacement is fully known from the informations measured by the inertial unit.