Optomechanical design of a wide-field auroral imager on Fengyun-3D

We present the optomechanical design and development of a wide-field auroral imager (WAI) on board the satellite Fengyun-3D. The optomechanical system of the WAI features a combination of a large field of view and a single-axis scanning mechanism. The combination makes the WAI perform better than its counterparts in temporal resolution in a low Earth orbit. In-orbit tests have verified the survival of WAI in the launching vibration and space environment. It has functioned on-orbit since 2018, with a spatial resolution of ∼10 at the nadir point, at a reference height of 110 km above the ionosphere.