CALACS Design: Lessons Learned from CALSTIS

This report documents the basic design of those parts of CALSTIS relevant for CALACS. A listing of the basic calibration steps required for ACS and a comparison of ACS with STIS provide the basis for determining what functionality needs to be retained or used from CALSTIS. Although CALSTIS provides a solid foundation for CALACS design, ACS data requires changes in how memory is managed along with new functionality to interpret the complex ACS associations. These changes are highlighted in the description of the overall design of CALACS, with its 5 tasks: CALACS, ACSCCD, ACS2D, ACSREJ, and ACSSUM. The HSTIO changes necessary to support this new pipeline and the implementation plan with testing schedule complete the description of how CALACS will be created from CALSTIS.