Field Correctors for Wide-Field CCD Imaging with Ritchey-Chretien Telescopes

Abstract

view Abstract Citations (3) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Field Correctors for Wide-Field CCD Imaging with Ritchey-Chretien Telescopes Epps, Harland W. ; Fabricant, Daniel Abstract The increasing availability of large format CCDs has made it possible to construct imaging arrays covering a 5 to 10 cm square format at moderate cost. In an era of 8 to 10 m telescopes, these large imaging arrays may extend the scientific usefulness of 1 to 2 m class telescopes, particularly if excellent image quality can be maintained across the large field of view. Many of these telescopes have Ritchey-Chretien optics with dominant off-axis image aberrations of field curvature and astigmatism. We briefly review the literature of one and two element refractive correctors for Ritchey-Chretien telescopes, and present variants optimized for CCD imaging. We describe a new family of two element field correctors that can provide excellent images (≤0.2") over a field diameter exceeding 0.5°. These new correctors have five appealing features: (1) they are compact, (2) they use only spherical surfaces, (3) they are constructed from fused silica, with high transmission over the entire optical band, (4) ghost images are well controlled, and (5) one of the corrector elements can serve as the dewar vacuum window to minimize the number of glass-air surfaces. We present two element corrector designs for the 1.2 m telescope at the Whipple Observatory and the 2.4 m Hiltner Telescope at the Michigan-Dartmouth-M.I.T. Observatory, and describe how to design such a corrector with a modern optical design program. Publication: The Astronomical Journal Pub Date: January 1997 DOI: 10.1086/118266 Bibcode: 1997AJ....113..439E Keywords: INSTRUMENTATION: CAMERAS full text sources ADS |