Fig. 1. Sketch maps of (a) single aperture imaging, (b) direct imaging and (c) indirect imaging of OSA

Fig. 2. Abbe imaging principle of (a) single aperture system and (b) OSA system

Fig. 3. Relationship between filling factor and MTF

Fig. 4. (a) Two-mirror OSA system; (b) MTFs before and after compensation

Fig. 5. Restored image (a) without and (b) with aberration correction

Fig. 6. Imaging plan

Fig. 7. Aperture structure

Fig. 8. Optical design of (a) four-aperture optical system and (b) single aperture system in Zemax

Fig. 9. Horizontal and vertical direction MTF of two sets of optical systems

Fig. 10. Simulation results of (a) OSA system imaging, (b) single aperture system imaging, (c) equivalent system imaging, and (d) fusion image