title: Determination of the Hubble Space Telescope effective conic-constant error from direct image measurements.
abstract: Direct measurement of discernible features in the Hubble Space Telescope (HST) imagery has enabled a self-consistent determination to be made of the effective conic constant of HST images taken with planetary camera 6 (PC-6) of the wide field and planetary camera. Before being corrected for the contribution from PC-6, the conic constant is - 1.01429 +/- 0.0002. The correction for PC-6 is less accurately determined but probably lies between -0.0002 and 0.0004. As a result the HST optics are characterized best by a conic constant of - 1.0140 +/- 0.0003 as obtained from direct image measurements.
authors.forename: A B
authors.initials: AB
authors.lastname: Meinel
authors.forename: M P
authors.initials: MP
authors.lastname: Meinel
authors.forename: D H
authors.initials: DH
authors.lastname: Schulte