Abstract: A method for correcting the thermoelastic effects on performance parameters of a telescope on board a space satellite, comprises a first step prior to the flight of the satellite consisting in determining, a priori, a correction of the thermoelastic effects by using a prior model of variations of the thermoelastic effects on the orbital scale and an algorithm for determining correction fed by programming data of the space satellite, and a second step carried out in flight, based on the correction determined a priori, consisting in establishing control messages of correction means for correcting the performance parameters of said telescope.

Abstract: A method is provided for the real-time determination of signals to be summed from signals representative of an image portion which are respectively received from detectors belonging to the same optical sensor, the detectors being organized in a matrix formed by rows and columns, the signals to be summed being received on the same column. The method also determines the time during which the detectors must acquire the signals to be summed. The method determines a value representative of a modulation transfer function of at least one lens and/or at least one mirror placed upstream of the optical sensor, and a signal-to-noise ratio of the image portion, based on a location of one of the detectors and on a signal representative of an image portion obtained from the detectors. This representative value is dependent on the number. The method searches for the number and the time maximizing the representative value.

Abstract: An optical monitoring device for an optical imaging system having a focal plane, an optical axis and an entry pupil, forming an image of a scene substantially at infinity on an image detector disposed substantially in the focal plane, comprises: a virtually point-like emission source at the periphery of the detector and substantially in the focal plane; a reflecting element with a plane surface upstream of the imaging system relative to the direction of light rays coming from the scene, and according to a position and inclination where a monitoring image of the source produced by the optical system and reflected by the reflecting element is substantially in the focal plane on a detection element connected to a monitoring image analyzer allowing potential optical defects to be identified; the reflecting element having an annular shape allowing passage of light rays coming from the scene and passing through the entry pupil.

Abstract: The general field provided is that of telescopes comprising an optical system and wavefront-analyzing placed in the focal plane of the optical system. The optical system comprises focusing optics and magnifying optics, the magnifying optics comprising a deformable mirror, the deformation of which is controllable. The telescope comprises monitoring the deformable mirror, comprising a source placed so that the image of the source, after reflection from the deformable mirror, is focused on the wavefront-analyzing. The monitoring comprises a movable mirror having two positions, a rest position and a monitoring position. The source may either be placed in the intermediate focal plane of the focusing optics, or at the focal point of a monitoring mirror, or even in the vicinity of the focal plane of the optical system.

Abstract: An optical monitoring device for an optical imaging system having a focal plane, an optical axis and an entry pupil, forming an image of a scene substantially at infinity on an image detector disposed substantially in the focal plane, comprises: a virtually point-like emission source at the periphery of the detector and substantially in the focal plane; a reflecting element with a plane surface upstream of the imaging system relative to the direction of light rays coming from the scene, and according to a position and inclination where a monitoring image of the source produced by the optical system and reflected by the reflecting element is substantially in the focal plane on a detection element connected to a monitoring image analyzer allowing potential optical defects to be identified; the reflecting element having an annular shape allowing passage of light rays coming from the scene and passing through the entry pupil.

Abstract: A method is provided for the real-time determination of signals to be summed from signals representative of an image portion which are respectively received from detectors belonging to the same optical sensor, the detectors being organized in a matrix formed by rows and columns, the signals to be summed being received on the same column. The method also determines the time during which the detectors must acquire the signals to be summed. The method determines a value representative of a modulation transfer function of at least one lens and/or at least one mirror placed upstream of the optical sensor, and a signal-to-noise ratio of the image portion, based on a location of one of the detectors and on a signal representative of an image portion obtained from the detectors. This representative value is dependent on the number. The method searches for the number and the time maximizing the representative value.

Abstract: A method for correcting the thermoelastic effects on performance parameters of a telescope on board a space satellite, comprises a first step prior to the flight of the satellite consisting in determining, a priori, a correction of the thermoelastic effects by using a prior model of variations of the thermoelastic effects on the orbital scale and an algorithm for determining correction fed by programming data of the space satellite, and a second step carried out in flight, based on the correction determined a priori, consisting in establishing control messages of correction means for correcting the performance parameters of said telescope.

Abstract: The multispectral filter for an image detection device comprises a prismatic plate (85) comprising a first internal face (86) and a second external face (87), the first and the second faces (86, 87) being inclined with respect to one another by an angle ?, and comprises at least two different spectral bands (91, 92, 93, 94) deposited either on the first or the second face (86, 87) of the prismatic plate (85), the various spectral bands (91, 92, 93, 94) being spaced a predetermined distance (D) apart. Application to multispectral imagers, in particular to Off Axis imagers. This filter allows the suppression of the ghost images (or spurious echoes) generated at the focal plane of a multispectral imager.

Abstract: The multispectral filter for an image detection device comprises a prismatic plate (85) comprising a first internal face (86) and a second external face (87), the first and the second faces (86, 87) being inclined with respect to one another by an angle ?, and comprises at least two different spectral bands (91, 92, 93, 94) deposited either on the first or the second face (86, 87) of the prismatic plate (85), the various spectral bands (91, 92, 93, 94) being spaced a predetermined distance (D) apart. Application to multispectral imagers, in particular to Off Axis imagers. This filter allows the suppression of the ghost images (or spurious echoes) generated at the focal plane of a multispectral imager.