Interaction of exposure time and system noise with angle-of-arrival measurements

摘要

Abstract: The interaction of exposure time and system noise with angle-of-arrival measurements taken with the Atmospheric Turbulence Measurement and Observation System (ATMOS) is presented. Of particular interest is the effect at short exposure times when viewing stellar images. Both measurements and simulated results at various exposure times are shown. An analysis is discussed of the effect on the variance of angle-of-arrival data for short exposures when the frame rate produces 'dead' time between samples. The dependency of the exposure time/system noise interaction on deriving accurate transverse coherence length (r$-o$/) and power spectral densities (PSD) of angle-of-arrival from centroid measurements using the ATMOS is presented.!