STScI Observatory Support 
STScI Home NASA Home AURA Home
Observatory Support
News and Advisories
Frequently Asked Questions
User Support
The Observatory Science Group (OSG) lies within the Science Support Division (SSD) at the Space Telescope Science Institute, and provides general support of HST as a productive observatory. This domain currently involves three main responsibilites:
  • Maintaining calibration parameters and throughput data for HST and its Science Instruments.
  • Supporting science through focal plane calibrations, SI aperture position determinations, and analysis of telescope pointing.
  • Monitoring focus variations and dependencies.
Further related duties include the Data Quality Coordinating Committee, an initiative to increase the scientific productivity of HST users by improving the data assessment, processing, calibration, and archiving functions.

New! Information for GOs on assessing roll accuracy in HST observations
New! HST Focus in Year 2000 (906K pdf file)
New! Memo on Focus entering SMOV (547K pdf file)

- News and Advisories  (last updated 8 Feb 2001)
New news and information.

Resources and Services
  • Pointing and Aperture Information
  • Focus and the OTA
  • Calibration Operations and Data (CDBS)

Please note: for most questions concerning the actual calibration of your particular
instrument's data, please see the appropriate instrument's Web Page.

- Reports  (last updated 8 Feb 2001)
References to documents and reports concerning the general calibration, focus / OTA,
and pointing / focal plane analyses for the Hubble Space Telescope.

- Frequently Asked Questions
Answers to questions concerning CDBS data, SIAF data, OTA, and pointing calculations.

- User Support
Information on contacts who can handle your questions and concerns.

Instruments - | - STScI

Questions? Send e-mail to

7 July 1998

Copyright Notice