Abstract: An optical device for a system presenting collimated images using a spherical mirror. The optical device makes it possible to present the user with an image corrected of off-centring distortion of a second kind due to an off-axis spherical mirror. In order to do this the optical device includes a tubular mirror whose optical characteristics ensure a high-quality image and correction of the off-centering distortion. The tubular mirror has a surface generated by the translation of a plane curve (a circular arc) along another plane curve (also a circular arc). The optical device is especially applicable to helmet sights for an aircraft pilot.

Abstract: The present invention relates to the management, on board an aircraft, of the aeronautical digital telecommunications networks ACARS and ATN. It covers a method for automatic choice of the transmission sub-network of the ACARS or ATN networks which is most appropriate for the exchange of digital messages with the ground, taking account of the capabilities of the equipment of the aircraft, of that existing on the ground in the area overflown, of the costs and of the reliabilities of the possible links, and of the preferences of the pilot, of his airline and of the control services.

Abstract: This method meets the constraints dictated by the instructed values of turning radius and by the instructed values of direction of approach in terms of route or course to be maintained at the obligatory points of passage. It includes, at the obligatory starting and arrival points of passage, in determining the turning paths that meet the instructed turning radius at these points. These turning paths are located, at each of the obligatory points of passage, on a pair of circles that are tangential to the points of passage, according to the instructed direction of approach valid at this point and oriented in this direction. Once these turning paths have been determined, a selection is made, from among them, according to simple rules, of an initial homing turning path and a final capture path that can be connected by a rectilinear linking path to go from the obligatory starting point of passage to the obligatory arrival point of passage while seeking the shortest possible distance of travel.

Abstract: A process for real-time reconfiguring of trajectories or airborne vehicles in order to adapt a mission to suit a new situation that has arisen through the occurrence of a disrupting event. The process updates real-time context data modified by the occurrence of the disrupting event and analyzes the new real-time context thus obtained in order to select a predefined reconfiguration method chosen from a set of different predefined methods stored in memory, each of these methods directly translating operational strategies customarily employed by aircrew in a given real-time context so as to determine a new trajectory which best suits the current real-time context.

Abstract: A method for position determination with the aid of GPS satellites, including reception processing of a GPS satellite signal L2 modulated by an encrypted code Y having a key not available from the GPS satellite, so as to assess a delay of the signal L2 with respect to the signal L1 and to deduce therefrom the magnitude of the ionospheric effect so as to take account thereof and improve the accuracy of the location finding.

Abstract: A simplified-fitting modular helmet resistant to aerodynamic stresses. The helmet has a base helmet and module, and includes between these two parts two lateral linking devices and an upper linking device. The linking devices include a finger secured to the module inserted into a socket secured to the base helmet and latchable in the assembled position of the helmet by a device of the quarter of a revolution type. The lateral fingers permit a small lateral clearance between the two parts of the helmet. Such a helmet may find particular application as an aircraft pilot helmet.

Abstract: A power supply device (201) for a light box (102) is provided for the backlighting of liquid crystal display screens. The device (201) includes a regulating DC/DC converter (204) of the booster type, powered directly by a 28-volt power supply so as to deliver directly a 50-volt stabilized DC voltage for powering the light box (102). The converter (204) includes an output diode (208) which protects the device. An energy reserve is obtained via a capacitor (209) supplied directly with the 50-volt voltage. A second converter (111) with galvanic isolation provides a set of supply voltages to electronic control cards (103) of display screens illuminated by the light box (102). A link between the light box (102) and the control cards (103) is effected by a galvanic isolation device (210). The device (201) makes it possible to increase the efficiency of the power supply so as to decrease weight, volume and cost thereof.

Abstract: An optical system for presenting an image to a user. The system includes an image source and an optical channel transmitting the image to the user's eye. It also includes an illumination of the ocular fundus and an imaging of the illuminated ocular fundus, both using part of the optical channel. The system enables an analysis of the eye retina observing an image. It also enables depending on the eye position, an adaptation of the visual image presented. If the system is partially mounted in a headset, it enables the presentation of the image to a mobile user.