P. Hickson et Eh. Richardson, A CURVATURE-COMPENSATED CORRECTOR FOR DRIFT-SCAN OBSERVATIONS, Publications of the Astronomical Society of the Pacific, 110(751), 1998, pp. 1081-1086
Citations number
13
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Publications of the Astronomical Society of the Pacific
Images obtained by drift-scanning with a stationary telescope are affe
cted by the declination-dependent curvature of star trails. The image
displacement due to curvature and drift-rate variation increases with
the angular field of view and can lead to significant loss of resoluti
on with modern large-format CCD arrays. We show that these effects can
be essentially eliminated by means of an optical corrector design in
which individual lenses are tilted and decentered. A specific example
is presented of a four-element corrector designed for the Large-Zenith
Telescope. The design reduces curvature errors to less than 0.'' 074
over a 10' x 20' field of view centered at 49 degrees declination. By
changing the positions and tilts of the lenses, the same design can al
so be used for any field centers between 0 degrees and +/-49 degrees.