In astronomical imaging, the errors in the wave-front slope are a significant cause of aberrations in the detected image. We investigate how the slope can be estimated optimally using an intensity measurement of the propagated wave front. We show that the optimal location for detection of wave-front tilt is the focal plane, and we quantify the error in using defocused images, such as would be obtained from a curvature sensor, for estimating the wave-front tilt. The effect of using broadband light is also quantified.
© 2002 Optical Society of America
Original Manuscript: February 7, 2001
Revised Manuscript: July 26, 2001
Manuscript Accepted: September 19, 2001
Published: April 1, 2002
Marcos A. van Dam and Richard G. Lane, "Tip/tilt estimation from defocused images," J. Opt. Soc. Am. A 19, 745-752 (2002)