Abstract: The present invention relates to estimating the attitude angles of an aircraft (1). The estimated attitude angles are generated by a device (9) that performs algorithmic integration on inertial measurements indicative of an angular velocity and of a linear acceleration. Horizontal components (34-39) of desired corrections are obtained by a linear combination of two horizontal components (32-33), with cross coefficients between said horizontal axes being continuous variable over time and dependent on the estimated rate of turn. As a result, the estimated attitude angles are stable, and the biases of the gyros continue to be estimated, including during stages during which the aircraft (1) is turning.

Abstract: The invention relates to a method of determining the position of an aircraft by combining inertial data with range data between the aircraft and satellites, in which: a) the range is stored in a FIFO memory so as make delayed range data available at the output from the memory; b) the delayed range data is combined with inertial data to obtain an estimate of position data for the aircraft; and c) a watch is maintained for the appearance of a fault in the range data, and when such a fault is detected, at least some of the data stored in the FIFO memory is modifying so as to be neutralized.

Abstract: A method of determining an angular velocity of an aircraft includes measuring the angular velocity using at least one gyro delivering a measured angular velocity signal affected by stochastic noise; measuring the angular acceleration of the aircraft using at least one accelerometer delivering a signal representing the angular acceleration of the aircraft; and using a filtering complementary in a frequency domain to combine a sum of the measured angular velocity signal and the angular acceleration signal so as to obtain a hybrid estimated angular velocity signal with reduced stochastic noise.

Abstract: The invention relates to a method of determining an estimated speed of an aircraft relative to ground being overflown by the aircraft, in which use is made of the sum of an acceleration measurement of the aircraft plus a difference value, the difference value being obtained from observation data or signals relating to a region of the ground.

Abstract: The invention relates to a method of determining the position of an aircraft by combining inertial data with range data between the aircraft and satellites, in which: a) the range is stored in a FIFO memory so as make delayed range data available at the output from the memory; b) the delayed range data is combined with inertial data to obtain an estimate of position data for the aircraft; and c) a watch is maintained for the appearance of a fault in the range data, and when such a fault is detected, at least some of the data stored in the FIFO memory is modifying so as to be neutralized.

Abstract: A process and device for estimating the vertical speed of a rotary wing aircraft may include integrating the sum of: (1) a first component corresponding to a vertical acceleration measurement and (2) a second component obtained from the difference between: (a) a first value incorporating a barometric measurement and (b) a second value incorporating a previous estimation of the vertical speed. The second component is derived from the difference between the first and second values by clipping this difference to eliminate, as appropriate, the part of the difference which is greater, in absolute value, than a predetermined value.

Abstract: A safe interactive navigation apparatus and method allows the crew of an aircraft to prepare and follow a safe flight plan without relying on instrument flying infrastructure. An aircraft navigation assistance method calculates a continuous, three-dimensional projected path on board the aircraft as a function of data related to the route and characteristics of the aircraft.

Abstract: The invention relates to a method of determining an estimated speed of an aircraft relative to ground being overflown by the aircraft, in which use is made of the sum of an acceleration measurement of the aircraft plus a difference value, the difference value being obtained from observation data or signals relating to a region of the ground.

Abstract: A process and device for estimating the vertical speed of a rotary wing aircraft may include integrating the sum of: (1) a first component corresponding to a vertical acceleration measurement and (2) a second component obtained from the difference between: (a) a first value incorporating a barometric measurement and (b) a second value incorporating a previous estimation of the vertical speed. The second component is derived from the difference between the first and second values by clipping this difference to eliminate, as appropriate, the part of the difference which is greater, in absolute value, than a predetermined value.

Abstract: The invention relates to an aircraft navigation assistance method, whereby a continuous, three-dimensional projected path is calculated on board the aircraft as a function of data relating to the route and characteristics of the aircraft.

Abstract: A process for estimating the vertical speed of a rotary wing aircraft may include integrating the sum of: (1) a first component corresponding to a vertical acceleration measurement and (2) a second component obtained from the difference between: (a) a first value incorporating a barometric measurement and (b) a second value incorporating a previous estimation of the vertical speed. The second component is derived from the difference between the first and second values by clipping this difference to eliminate, as appropriate, the part of the difference which is greater, in absolute value, than a predetermined value.

Abstract: Process and device for estimating at least the vertical speed of an aircraft, in particular of a rotary wing aircraft.

Abstract: The present invention concerns a method and a device (1) operating by intepolation in a discrete spectrum to determine characteristics Pq of a signal s(t,Pq). In accordance with the invention, said device (1) includes means (2, 4, 6, 8, 10, 12) for determining said characteristics Pq from a system of m equations: z(fi)=Fi[w(t).s(t,Pq)].h(f), i varying from 1 through m and m being greater than or equal to 2, wherein: z(fi) is an element of a discrete spectrum obtained by Fourier transformation of the signal s(t,Pq), Fi is a discrete Fourier transform, w(t) is a temporal weighting function, and h(f) is a frequency transfer function of an anti-aliasing filter.

Abstract: The present invention relates to a method and a device for correcting measurement errors of a magnetometer mounted on a vehicle. According to the method, a theoretical corrective model is defined in accordance with the following equation: ##EQU1## where ?A!, ?C!i and Hp are elements to be determined, Hm is the measured field, H the effective field, and ?M! is a transformation matrix, and in which a vector error is defined in accordance with the following equation: ##EQU2## where the square of the error thus defined is determined and the coefficients of the model which minimize the sum of the squares of the error moduli for all the measurements taken are identified.

Abstract: The present invention relates to a method and to a device (1) for correcting measurement errors of a magnetometer (2) mounted on a vehicle (3). According to the invention:a theoretical corrective model [A].Hm+a.Hm'+Hp=[M].H is defined, in which [A], a and H are elements to be determined, Hm is the measured field, Hm' the time derivative of Hm, H the effective field and [M] a transformation matrix;a vector error E=[M].H-([A].Hm+a.Hm'+Hp) is defined;the square of the error thus defined is determined; andthe coefficients of the model which minimize the sum of the squares of the errors for all the measurements taken are identified.