MWIR imaging experiments with large F-number optics on LEO spacecraft

To determine the feasibility of spacecraft imaging in the mid-infrared region (3.0–5.0 μm) utilizing large F-number optics, we create a radiometric simulation of a low-Earth orbit (LEO) extended object, imaging background and noise, in order to predict the signal-to-noise ratio of such objects as viewed from a telescope during the daytime and terminator, etc. We find that the observation of Space Station and other extended targets utilizing large F-number optics for MWIR imaging is possible, given the right conditions. We have developed a large F-number infrared camera with cold stop matched, which is successfully applied to acquire LEO extended object images taken by a 1.23 m telescope. We get clear images of International Space Station, Tian-gong, etc. and our proposed the infrared imaging technology can be demonstrated to greatly improve the imaging ability of current ground-based Optoelectric (OE) telescope for the detection of space activities.