SEGMENTED MIRROR ALIGNMENT WITH FAR-FIELD OPTIMIZATION IN THE PRESENCE OF ATMOSPHERIC-TURBULENCE

The remote alignment of segmented mirror active optics with far-field optimization is reported. Far-field optimization eliminates the need f or a wave-front sensor or gap sensors since it does not require any ne ar-field measurements, but uses simple measures of the point-spread fu nction as figures of merit. The simplex function minimization algorith m is used to configure iteratively the segmented mirror to alignment. We present results of computer simulations to demonstrate the applicat ion of far-field optimization to the segmented mirror alignment in the presence of atmospheric turbulence. The effects of static as well as dynamic Kolmogorov turbulence (turbulence phase screen drifting across the telescope aperture) are studied. We find that the segmented mirro r alignment is fairly insensitive to the speed of drifting turbulence and aligns a segmented mirror active optical system with adequate corr ection bandwidth in a few seconds.