Abstract: A method for estimating the motion of a carrier with respect to an environment in relation to which the carrier is moving. The carrier bearing a navigation sensor and a vision sensor producing images of the environment. In the images acquired by the vision sensor, the characteristic elements of the images representing characteristic elements of the environment are identified. At least one condensed measurement is calculated as a function of characteristic elements of at least two images acquired at different instants. The motion of the carrier by a navigation filter is estimated, as a function of navigation measurements carried out and as a function of the condensed measurement. The condensed measurement is calculated as a function furthermore of a priori estimation of the motion, as provided by the navigation filter.

Abstract: A method for calibrating spatial errors induced by phase biases having a detrimental effect on the measurements of phase differences of radio signals received by three unaligned receiving antennas of a vehicle. An inter-satellite angular deviation of a pair of satellites is estimated in two different ways: on the basis of the respective positions of the vehicle and of the satellites to obtain a theoretical inter-satellite angular deviation; and on the basis of the respective directions of incidence of the satellites relative to the vehicle, which are determined from phase measurements, to obtain an estimated inter-satellite angular deviation. The space errors are estimated on the basis of said theoretical and estimated inter-satellite angular deviations. Also, a method and system for estimating the attitude of a vehicle, in particular a spacecraft.

Abstract: A method for estimating the motion of a carrier with respect to an environment in relation to which the carrier is moving. The carrier bearing a navigation sensor and a vision sensor producing images of the environment. In the images acquired by the vision sensor, the characteristic elements of the images representing characteristic elements of the environment are identified. At least one condensed measurement is calculated as a function of characteristic elements of at least two images acquired at different instants. The motion of the carrier by a navigation filter is estimated, as a function of navigation measurements carried out and as a function of the condensed measurement. The condensed measurement is calculated as a function furthermore of a priori estimation of the motion, as provided by the navigation filter.

Abstract: A method of controlling the attitude of a satellite in orbit around a celestial body. The attitude of the satellite being controlled by a momentum storage device and controllable surfaces of the satellite configured to create desaturation torques in the storage device by using solar pressure. The controllable surfaces are arranged on solar panels mobile in rotation around an axis Y. At least one electric thruster configured to control the orbit of the satellite also controls the attitude of the satellite. The orientation of the electric thruster is controlled to activate the electric thruster with a thrust direction deliberately not aligned with a center of mass of the satellite to create desaturation torques in the storage device along axis Y. The controllable surfaces are controlled to create desaturation torques of the storage device in a plane orthogonal to the Y axis.

Abstract: A method for calibrating spatial errors induced by phase biases having a detrimental effect on the measurements of phase differences of radio signals received by three unaligned receiving antennas of a vehicle. An inter-satellite angular deviation of a pair of satellites is estimated in two different ways: on the basis of the respective positions of the vehicle and of the satellites to obtain a theoretical inter-satellite angular deviation; and on the basis of the respective directions of incidence of the satellites relative to the vehicle, which are determined from phase measurements, to obtain an estimated inter-satellite angular deviation. The space errors are estimated on the basis of said theoretical and estimated inter-satellite angular deviations. Also, a method and system for estimating the attitude of a vehicle, in particular a spacecraft.

Abstract: A method of controlling the attitude of a satellite in orbit around a celestial body. The attitude of the satellite being controlled by a momentum storage device and controllable surfaces of the satellite configured to create desaturation torques in the storage device by using solar pressure. The controllable surfaces are arranged on solar panels mobile in rotation around an axis Y. At least one electric thruster configured to control the orbit of the satellite also controls the attitude of the satellite. The orientation of the electric thruster is controlled to activate the electric thruster with a thrust direction deliberately not aligned with a center of mass of the satellite to create desaturation torques in the storage device along axis Y. The controllable surfaces are controlled to create desaturation torques of the storage device in a plane orthogonal to the Y axis.

Abstract: A method (10) for estimating a carrier's movement relative to an environment (20) with respect to which the carrier moves, the carrier having at least one navigation sensor and one vision sensor producing 2D images of the environment installed, The method (10) includes the following steps: i) (12) identifying, in images acquired by the vision sensor, characteristic elements of the images representing characteristic elements of the environment, ii) (14) calculating, based on characteristic elements of a triplet of images acquired at different times, at least one condensed measurement representative of characteristics of the carrier's movement during the acquisition of the triplet's images, iii) (16) estimating the movement by a navigation filter, based on navigation measurements made by the navigation sensor and on the at least one condensed measurement. A computing device for a navigation system of a carrier is also described.

Abstract: A method (10) for estimating a carrier's movement relative to an environment (20) with respect to which the carrier moves, the carrier having at least one navigation sensor and one vision sensor producing 2D images of the environment installed, The method (10) includes the following steps: i) (12) identifying, in images acquired by the vision sensor, characteristic elements of the images representing characteristic elements of the environment, ii) (14) calculating, based on characteristic elements of a triplet of images acquired at different times, at least one condensed measurement representative of characteristics of the carrier's movement during the acquisition of the triplet's images, iii) (16) estimating the movement by a navigation filter, based on navigation measurements made by the navigation sensor and on the at least one condensed measurement. A computing device for a navigation system of a carrier is also described.

Abstract: The invention relates to a solar control method for spacecraft. The inventive method can be used for the three-dimensional control of a spacecraft (10) comprising a body (12) which is equipped with means of creating internal kinetic moments (14) and bearing two wings (16a, 16b) which are provided with solar panels. The aforementioned wings are disposed symmetrically on either side of the body of the craft (10) and can be oriented independently on the body (12) around a common axis (K). In addition, said wings are provided with elements (18a, 18b) which create a solar pressure force that is offset in relation to the axis of rotation (K) on one wing (16a, 16b) when said wing (16a, 16b) is mispointed around the aforementioned axis (K) in relation to the sun. In order to create a moment that can change the orientation of the craft (10) around a windmill axis (J) which is orthogonal to the mid-plane of the wings (16a, 16b), the wings (16a, 16b) are mispointed in an opposing member.

Abstract: A satellite has a platform of elongated shape in a direction parallel to a roll axis of the satellite. A deployable arm is pivotally carried by a longitudinally extending face of the platform. A solar generator is carried at the end of the arm by a first motor for aiming the generator through a range of 360° about a pitch axis orthogonal to the direction of elongation of the platform. A second motor rotates the solar generator through a limited angular range about an axis that is orthogonal to the pitch axis and parallel to the plane of the generator. The arm, when deployed, moves the solar generator away from on a stored position in contact with the platform in a direction of a yaw axis.

Abstract: An earth orbiting satellite is enabled to assume a "survival mode" of operation in which its x axis is aligned with the sun by observing characteristics of the movement of the frame of the satellite (e.g. its x axis) relative to the sun and performing calculations based on those operations. A more accurate result is achieved if a deliberate offset is introduced between the mean direction of the x axis and the sun's direction. The control arrangement for positioning the x axis with this offset is preferably adaptive, resulting in control of the satellite's thrusters so as to produce oscillation of the x axis in a way which allows suitable measurements to be taken.

Abstract: The attitude of a satellite placed on a non-heliosynchronous earth orbit in a plane that is inclined relative to the equatorial plane of the earth is controlled for efficient use of solar panels and radiators. The satellite has a structure, solar panels apt to be rotated with respect to the structure rotation and two opposed radiators each fixed on one of two opposed faces of the satellite structure which are orthogonal to the rotation axis. One of the radiators has greater emissivity than the other. A yaw axis bound to the structure satellite and orthogonal to rotation axis is aimed towards the earth. The solar panels of the satellite are maintained in an optimum orientation relative to the sun by rotating them. At least during periods of each year when an angle .beta.