Abstract: The invention relates to a self-contained device (4) for blanking out the light rays from at least one star (1), which device (4) comprises means (43) for controlling propulsion means (44) which are in turn capable of moving or halting the device (4) in space and/or on a pseudo-orbit in space around an observation telescope (2) comprising an observation opening (21), characterized in that it comprises a blanking-out screen (40), wherein the means (43) for controlling the propulsion means (44) are further capable of positioning the screen (40) on the sighting axis (3) between the telescope (2) and the star (1) during an observation period such that the light rays from the star (1) are at least partially blanked out during said observation period as far as said observation opening (21) is concerned. The invention further relates to an assembly comprising at least one such device and a method for using said device or said assembly.

Abstract: The invention concerns an observation satellite (1) which is intended to be placed in orbit around a celestial body (2), and which comprises a reflecting device (5), a receiving device (6), a linking mechanical system (19), the whole forming a capture system (3) which is suitable to be able to orient the capture system (3) by gravity gradient in an aiming position in which the electromagnetic radiation corresponding to the information to be captured is received. The invention extends to an observation method and a fleet of such satellites (1).

Abstract: The invention relates to a self-contained device (4) for blanking out the light rays from at least one star (1), which device (4) comprises means (43) for controlling propulsion means (44) which are in turn capable of moving or halting the device (4) in space and/or on a pseudo-orbit in space around an observation telescope (2) comprising an observation opening (21), characterised in that it comprises a blanking-out screen (40), wherein the means (43) for controlling the propulsion means (44) are further capable of positioning the screen (40) on the sighting axis (3) between the telescope (2) and the star (1) during an observation period such that the light rays from the star (1) are at least partially blanked out during said observation period as far as said observation opening (21) is concerned. The invention further relates to an assembly comprising at least one such device and a method for using said device or said assembly.

Abstract: The invention relates to radar interferometry apparatus comprising at least one emitter satellite (E) and a constellation of receiver satellites (S). The receivers are accurately synchronous and their orbits have the same eccentricity which is different from that of the orbit of the emitter. During one orbital period, the satellites travel round a relative ellipse (G) over which they are uniformly distributed. The invention provides applications specifically to measuring ocean currents, measuring world topography, and differential interferometry.

Abstract: A method of geoid measurement and/or earth imaging, characterized in that at least one directional antenna (2) is used to pick up a radio signal from a satellite and reflected on the ground, and said signal is processed using a reference signal that corresponds to the radio signal from the satellite in order to obtain a geodesic measurement and/or an image of the zone (Z) towards which the directional antenna (2) is pointed.