A comparison of optical architectures for constrained long-range imaging

Long-range airborne full-motion-video systems require large apertures to maximize multiple aspects of system performance, including spatial resolution and sensitivity. As systems push to larger apertures for increased resolution and standoff range, both mounting constraints and atmospheric effects limit their effectiveness. This paper considers two questions: first, under what atmospheric and spectral conditions does it make sense to have a larger aperture; second, what types of optical systems can best exploit movement-constrained mounting? We briefly explore high-level atmospheric considerations in determining sensor aperture size for various spectral bands, following with a comparison of the swept-volume-to-aperture ratio of Ritchey-Chretien and three-mirror-anastigmat optical systems.