Impact of segmentation errors and detector quantization on nonsolar planet detection using a space-based adaptive optical telescope

摘要

Abstract: This study examines the impact of optical aberration and detector spatial quantization on the detection of nonsolar earth-like planets. It describes the use of a Lyot coronagraph/CCD based system implemented on a space-based segmented telescope platform. The coronagraph consists of a cross shaped apodizer in the first focal plane followed by a 75% transmission circular corner Lyot stop at the pupil plane. At the final focus plane, a 2D CCD focal plane array is introduced. The pixel elements on the CCD are varied in size to examine the degrading aspects of finite spatial quantization. Performance results are described in terms of three detectability metrics evaluated for various star-to-planet separations. Robustness of these metrics to segmentation phasing and tilt errors in the primary mirror are discussed. The effect of planet placement within a pixel on signal variability and the utility of detectability metrics is also examined.!3