Abstract

Astronomers have long known that the resolution in ground-based astronomy is almost always limited by aberrations introduced by the atmosphere. Over the years, researchers have developed a variety of clever pre- and post-detection approaches for correcting these effects. A strong argument can be made for pre-detection correction. It can be shown that the Modulation Transfer Function (MTF) will achieve a maximum at each spatial frequency when the system is unaberrated [1]. Aberrations can only modulate object spatial-frequency information to reduced levels. This modulation could be perfectly inverted in the absence of noise. However, detection of the imagery always introduces noise and inversion schemes result in noise amplification. Therefore, when it can be successfully accomplished, pre-detection correction is preferable to post-detection correction with regard to signal-to-noise ratio.

© 1996 Optical Society of America