Matra

About: Matra is a based out in . It is known for research contribution in the topics: Signal & Detector. The organization has 1330 authors who have published 1216 publications receiving 17967 citations.

Procédé de mise en oeuvre d'une unité de service de trafic air

Abstract: L'invention concerne un procede de mise en oeuvre de l'unite de service de trafic air (ATSU) qui gere les liaisons entre certains equipements avion et les moyens de communications sol/bord, et dont le systeme d'exploitation (OS) gere les entrees/sorties, l'utilisation des ressources logicielles et materielles, l'enchainement et le cadencement des applications, qui sont des programmes realisant des fonctionnalites du systeme avion, dans lequel on utilise des mecanismes de decoupage de la memoire, et des mecanismes de decoupage de l'unite centrale ; dans lequel on filtre les appels au systeme d'exploitation de maniere a interdire auxdites applications de type AOC (Airline Operational Communication) de perturber le fonctionnement de ladite unite de service de trafic air.

The evolutionary optimisation of shaped and minimum sidelobe radiation patterns for synthetic aperture radars

Abstract: This paper presents a technique of optimising the aperture excitations of a N-element linear array of radiating elements for a spaceborne synthetic aperture radar (SAR), given a required far-field beam shape template. This method uses evolutionary or genetic algorithms to search and locate the best solution to the problem. It outlines how this technique may be applied to different types of space based SAR arrays and the various complications that are encompassed within the optimisation problem due to the real space scenario.

Coarse pointing assembly for the SILEX program, or how to achieve outstanding pointing accuracy with simple hardware associated with consistent control laws

Abstract: Attention is given to the coarse pointing assembly (CPA) for the SILEX program, designed on the basis of 10 years of MATRA experience in very accurate drive mechanisms successfully conducted by the SPOT 1 and 2 flights as well as EURECA IOC. The basic key design feature of the mechanism is a 1200-step stepper motor driven in microstepping with harmonic defects compensation. This allows very low torque noise associated with a high accuracy (0.01 deg). The direct drive principle avoids backlash and permits a linear control of the output shaft of each drive. The only parts susceptible to possible wear are the ball bearings, which have a design margin of greater than 1000 for 10 yr of service life. In order to meet the dynamic performances required by SILEX, a closed loop active damping system is added to each drive unit. Two accelerometers used in a differential way sense the hinge microvibrations and an active damping loop reduces their Q factor down to a few dB. All CPA electrical parts (including motor, optical encoder, and accelerometer) are redundant to avoid single point of failure.