Fabrication and testing of STREEGO: a compact optical payload for earth observation on small satellites

In the framework of an European Space Agency contract, Media Lario Technologies is developing an optical payload for Earth Observation targeted to small satellites. In this paper we present a detailed description of the imager which, by leveraging on aspheric surfaces, bonnet polishing, lightweight materials, an off-the-shelf large format CMOS detector and multispectral filters integrated in the FPA, achieves remarkable image quality with compact volume claim and mass of only 15 kg. The instrument is based on a three mirror anastigmat (TMA) design with an aperture of 200 mm and an F/number of 6. The payload is designed to provide a ground sampling distance (GSD) of 2.75 m for the panchromatic channel at a reference altitude of 600 km, a field of view of 1° and a nominal MTF greater than 60% at Nyquist frequency with a Signal to Noise Ratio (SNR) greater than 100.