Space-based airglow imaging observation is significant for monitoring global atmospheric waves in the mesopause region. The Time Delay and Integration Charge Coupled Device (TDICCD) is used to capture images of O
2A (0-0) airglow. The required exposure time and the signal-to-noise ratio are calculated, and the latitude-dependent space resolutions are analyzed with a modulation transfer function. Due to the Earth's rotation, for a circular orbit with a height of 700km and an incline angle of 73°, the spatial resolution increases with in creasing latitudes, which is 5.7km near the equator. Based on the above analysis, the instrument's block diagram is also given. Results indicate that the space-based airglow imager can observe atmospheric waves with a vertical wavelength of approximately 10km or longer and with the best horizontal spatial resolution of 0.33km.