Design of integrated searching and tracking optical systems based on freeform mirrors

Target searching and tracking photoelectric systems are widely used in civil and military fields. Achieving both efficient search and fine-observation imaging while minimizing the volume and weight of the system is the most concerning problem. In this paper, a dual-mode integrated optical system is proposed, which shares large size components between large field of view (FOV) search module and high-resolution tracking module by using the Biconic Zernike freeform mirrors. Compared with the traditional searching and tracking system utilizing multi-camera matching, this scheme significantly reduces the volume and weight of the remote sensing payload. At the orbit altitude of 500 km, this proposed system has a swath of 87.5 km with a ground resolution of 10 m in search mode. In tracking mode, it can observe an area of 19 km² with a ground resolution of 1 m. It can meet the requirements of wide-area search and focus tracking simultaneously, providing a feasible scheme for the lightweight design of space optical cameras.