Anew High Speed Two-Dimensional Ccd Atmospheric Turbulence Monitor

A new atmospheric turbulence monitor utilizes relative motion between dual images of a single star, formed by two subapertures of a Schmidt-Cassegrain telescope, to calculate Fried's atmospheric seeing parameter, r0. Dual images are formed on a two-dimensional CCD array, and intensity at each pixel location is digitized for calculations by the host computer. Flexibility in frame rate, exposure time, and data processing are incorporated into the system design through extensive use of programmable array logic, state machines, and microcomputer control. The equipment eliminates many problems characteristic of current systems which use one-dimensional detectors and a single image.