How to Use this Handbook

This handbook was created to help users process and analyze data from the Advanced Camera for Surveys (ACS) which was installed on-board the Hubble Space Telescope (HST) during the 2002 servicing mission (SM3B). It is presented as an independent and self-contained document, designed for users familiar with HST data but new to ACS. Users who wish to find more general data analysis information, including instructions for retrieving data from the HST Archive, a description of HST file formats, and details regarding data analysis software supported by STScI, are referred to a companion volume, the Introduction to HST Data Handbooks.

For information about geometric distortion and drizzling ACS data, please refer to the DrizzlePac website.

Since many of the instrument characteristics may be revised over a short time frame, readers are advised to consult the ACS website ( for the latest information regarding ACS performance and calibration.

STSDAS and PyRAF are soon to be deprecated, and are now only recommended/supported where necessary, specifically for use in slitless spectroscopy in aXe. Their usage in aXe will be deprecated in the future, as well. All other data processing described herein now uses Python available via the STScI AstroConda channel website.