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. Farfield optimization eliminates the need for a wave-front sensor or gap sensors since it does not require any near-field measurements, but uses simple measures of the point-spread function as figures of merit. The simplex function minimization algorithm is used to configure iteratively the segmented mirror toalignment. We present results of computer simulations to demonstrate the application 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 mirror alignment is fairly insensitive to the speed of drifting turbulence and aligns a segmented mirror active optical system with adequate correction bandwidth in a few seconds.