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Optics for Astrometry:a quick introduction

William F. van Altena

Yale UniversityBasic Astrometric Methods

Yale University

July 18-22, 2005

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Filters and windows -1

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Filters and windows - 2

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Filters and focal length

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Filters and focal length

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Filter flatness

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Filter flatness

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The Seidel Aberrations

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First-order theory

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S1 - Spherical aberration

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S1 and lens shape

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S1 and the caustic curve

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S1 and the HST

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S1 and astrometry

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S2 - Coma

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S2 - zonal variation

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S2 - minimizing coma

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S2 and astrometry

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S3 - Astigmatism

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S3 and image shape

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S3 and astrometry

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S4 - Field Curvature

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S5 - OFAD

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S5 and field stops

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S6 - Chromatic aberration

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Reflecting telescopes

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Conic sections

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Aberrations in reflectors

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The sagittal depth

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Spherical aberration

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Higher-order aberrations - 1

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Higher-order aberrations -2

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Two-mirror telescopes

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Normalized parameters

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Reflector types

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Angular aberrations

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Classical Cass & the R-C

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Optical alignment errors

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Tilt and Decenter

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Despace

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Alignment error example

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Relative aberrations

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“Sky errors”

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Useful relations

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Tangent point location

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Astrometric correction formulae