Abstract: A constellation of satellites comprising at least two satellites in the same orbit is used to measure atmospheric wind speeds by means of a spatial wind lidar; each satellite carries a Doppler lidar, with a fixed sight axis. The orbit is a polar or quasi-polar orbit, with an orbital altitude from 350 to 500 km. The sight angles and the distribution of the satellites in the orbit are chosen so that the tracks on the surface of the Earth of the sight axes of the satellites of the constellation are substantially coincident over half of the surface of the Earth and regularly distributed over the other half of the surface of the Earth.

Abstract: A constellation of satellites comprising at least two satellites in the same orbit is used to measure atmospheric wind speeds by means of a spatial wind lidar; each satellite carries a Doppler lidar, with a fixed sight axis. The orbit is a polar or quasi-polar orbit, with an orbital altitude from 350 to 500 km. The sight angles and the distribution of the satellites in the orbit are chosen so that the tracks on the surface of the Earth of the sight axes of the satellites of the constellation are substantially coincident over half of the surface of the Earth and regularly distributed over the other half of the surface of the Earth.

Abstract: The invention concerns a method and an apparatus for processing alphanumeric and graphics information recorded in page form on a system to create a data base which can be searched and edited, wherein the following steps take place automatically:A) determination of digitized page images;B) a first phase of processing digitized page images providing: verification that these pages are sequential, determination of the characteristic elements on each page, determination of the angle of deviation, mask formation, window formatting, alignment correction, identification of characteristic elements, image segmentation; recording in separate files the digitized page images, the digital image entities and the digitized segmented images accessible for editing;C) a second processing phase consisting of optical character recognition of the components relative to the alphanumeric data from the segmented images and recording the data in a file to create a data base which can be searched.

Abstract: A method and apparatus to perform the observation and imaging from a space vehicle by scanning of a celestial body with reference to a scanning axis, forming successively two signals corresponding to the scanning in a given directional series of a line or band including ground area, detecting in each of these signals a characteristic transition representative of a given characteristic point of this line or band of ground, reading the relative position of these transitions in these signals, and determining an angular velocity of the space vehicle from any divergence between these relative positions while taking into account the time interval separating the instants where each of these transitions appeared in the aforementioned formed signals.