Abstract: A method for the acquisition of images by a spacer airborne optical instrument, comprises the following steps: a) acquisition, by the instrument, of a first image having a first field of view including the projection on the ground of the optical axis of the instrument and delimited by a first field edge, the first image being sampled spatially with a first sampling step; b) acquisition, by the same instrument, of a second image having a second field of view not including the projection on the ground of the optical axis of the instrument and extending beyond the first field edge, the second image being sampled spatially with a second sampling step greater than the first sampling step. Space or airborne optical instruments and an image acquisition system for implementing the method are provided.

Abstract: A method for the acquisition of images by a spacer airborne optical instrument, comprises the following steps: a) acquisition, by the instrument, of a first image having a first field of view including the projection on the ground of the optical axis of the instrument and delimited by a first field edge, the first image being sampled spatially with a first sampling step; b) acquisition, by the same instrument, of a second image having a second field of view not including the projection on the ground of the optical axis of the instrument and extending beyond the first field edge, the second image being sampled spatially with a second sampling step greater than the first sampling step. Space or airborne optical instruments and an image acquisition system for implementing the method are provided.

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: 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: In the field of optic instruments comprising at least one optical architecture, a photoreception assembly and means for acquisition and analysis of the images arising from the said photoreception assembly, the acquisition and analysis means comprising an algorithm of phase diversity type, an optical architecture comprises an optical plate of low or zero optical power arranged in the vicinity of the photoreception assembly and disposed so as to form on all or part of the said assembly a first focused image and a second image defocused by a first predetermined value and shifted by a second predetermined value with respect to the first image. The optic instrument can advantageously be a space telescope.

Abstract: Optical devices can comprise a deformable mirror and a system for deforming said mirror. A deformation system comprises a first mechanical structure comprising a first surround, one or more electromechanical actuators attached to the first mechanical structure, a second mechanical structure comprising a substantially planar bottom and a second surround, both deformable, the bottom being attached to the first surround, the second surround being attached to the surround of the mirror, a rigid stud being attached to the bottom, substantially planar and centerd on the bottom, the electromechanical actuator or actuators exerting predetermined forces or bending moments on the stud so as to generate a particular distribution of the bending moments on the surround of the mirror, deforming it according to a geometrical form representative or of one or more predetermined geometrical aberrations.

Abstract: A scanning multispectral telescope comprises an optical architecture arranged so as to focus the image of an object in the vicinity of a photodetection assembly, the area of focus being an image plane. The photodetection assembly comprises a number of parallel rows of photodetectors, each row being dedicated to a particular spectral band, each spectral band being centered on a mean wavelength. The telescope comprises means for acquiring and analyzing the images obtained from the rows of photodetectors using a phase diversity algorithm. Finally, the telescope comprises optical or mechanical means arranged in such a way that at least one of the rows of photodetectors is offset by a fraction of the mean wavelength which corresponds to it on an axis perpendicular to the image plane.

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: In the field of optic instruments comprising at least one optical architecture, a photoreception assembly and means for acquisition and analysis of the images arising from the said photoreception assembly, the acquisition and analysis means comprising an algorithm of phase diversity type, an optical architecture comprises an optical plate of low or zero optical power arranged in the vicinity of the photoreception assembly and disposed so as to form on all or part of the said assembly a first focused image and a second image defocused by a first predetermined value and shifted by a second predetermined value with respect to the first image. The optic instrument can advantageously be a space telescope.

Abstract: In the field of optical checking of optical instruments of telescope type, an instrument comprises an optical objective, a photo-detection housing arranged at the focus of said optical objective and at least one light source arranged in the vicinity of said photo-detection housing, the optical pupil of the optical objective having a first diameter. The checking means comprise a plane mirror having a second diameter that is smaller than the first diameter and means to arrange the plane mirror such that the image of the light source given by the optical objective and reflected by said plane mirror is focused on the photo-detection housing, means for analyzing said image received making it possible to determine the optical quality of the telescope. The plane mirror may be associated with an autonomous checking bench. It may also form part of the telescope and be incorporated into the protection hood for the optic.

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: Optical devices can comprise a deformable mirror and a system for deforming said mirror. A deformation system comprises a first mechanical structure comprising a first surround, one or more electromechanical actuators attached to the first mechanical structure, a second mechanical structure comprising a substantially planar bottom and a second surround, both deformable, the bottom being attached to the first surround, the second surround being attached to the surround of the mirror, a rigid stud being attached to the bottom, substantially planar and centred on the bottom, the electromechanical actuator or actuators exerting predetermined forces or bending moments on the stud so as to generate a particular distribution of the bending moments on the surround of the mirror, deforming it according to a geometrical form representative or of one or more predetermined geometrical aberrations.

Abstract: In the field of optical checking of optical instruments of telescope type, an instrument comprises an optical objective, a photo-detection housing arranged at the focus of said optical objective and at least one light source arranged in the vicinity of said photo-detection housing, the optical pupil of the optical objective having a first diameter. The checking means comprise a plane mirror having a second diameter that is smaller than the first diameter and means to arrange the plane mirror such that the image of the light source given by the optical objective and reflected by said plane mirror is focused on the photo-detection housing, means for analyzing said image received making it possible to determine the optical quality of the telescope. The plane mirror may be associated with an autonomous checking bench. It may also form part of the telescope and be incorporated into the protection hood for the optic.

Abstract: A scanning multispectral telescope comprises an optical architecture arranged so as to focus the image of an object in the vicinity of a photodetection assembly, the area of focus being an image plane. The photodetection assembly comprises a number of parallel rows of photodetectors, each row being dedicated to a particular spectral band, each spectral band being centred on a mean wavelength. The telescope comprises means for acquiring and analyzing the images obtained from the rows of photodetectors using a phase diversity algorithm. Finally, the telescope comprises optical or mechanical means arranged in such a way that at least one of the rows of photodetectors is offset by a fraction of the mean wavelength which corresponds to it on an axis perpendicular to the image plane.

Abstract: An optical space observation system comprises a primary mirror, a secondary mirror, a supporting base containing the primary mirror, on which a mechanical structure bearing a support of the secondary mirror is positioned, and an optical measurement means, said mechanical structure comprising a plurality of mechanical arms. The system also has a system comprising a plurality of actuators positioned on the supporting base, said actuators being connected to the lower ends of said mechanical arms and the upper ends of said mechanical arms being connected to the support of the secondary mirror on the periphery of the support. A space telescope is intended to be loaded in a launcher and put into orbit. The invention is intended in particular for a telescope having a deployable secondary mirror and means for active control of the optics.