Image processing for a formation flying synthetic aperture telescope

Small satellites have been used for remote sensing with a spatial resolution of several meters from LEO in recent years. However, it is difficult to increase temporal resolution for LEO remote sensing due to the short orbital period. Therefore, GEO remote sensing which enables observation of high temporal resolution from GEO or its nearby orbit is getting important. In order to obtain enough spatial resolution in GEO remote sensing, an optical system having a diameter of several meters is required because of the diffraction limit. It takes huge cost to realize such a large diameter primary mirror due to manufacturability and required accuracy. To address this problem, we propose a synthetic aperture telescope by small satellites formation flying. The synthetic aperture telescope is composed of several mirror satellites constituting a primary mirror of the telescope and an imaging satellite having a focal plane assembly. By optically synthesizing the light collected by each mirror satellite with the imaging satellite, a virtual large aperture telescope is constructed. In this paper, we assume the observation at near infrared to short wavelength infrared and show the specifications of the system. The apperture telescope and the image processing method used to extract high spatial frequency information from the observed images are also described.