11.1 Introduction to the ACS

The Instrument Configurations and Operating Modes described in this chapter are used for the Visit and Exposure Specifications. The legal Visit and Exposure Specifications entries are discussed in the following sections. More complete descriptions of Instrument Configurations, Modes, Apertures, Spectral Elements, etc. are available in the ACS Instrument Handbook.

Many of the Optional Parameters have default values. In such cases an Optional Parameter entry in these Specifications is necessary only if it is desired to override the default value. In the STScI proposal system, the physical units of Optional Parameter quantities are always implicit and should never be entered by the observer.

The following tables list the permitted Instrument Configurations, Operating Modes, Apertures, Spectral Elements, and Optional Parameters for the ACS.

Table 11.1: Supported Instrument Parameters for the ACS

Config	Mode	Aperture	Spectral Elements	Optional Parameters
ACS/WFC	ACCUM	WFC, WFC-FIX, WFC1, WFC2, WFC1-CTE, WFC1-FIX, WFC2-FIX WFCENTER, WFC1-512, WFC1-1K, WFC1-2K, WFC1-IRAMP, WFC1-MRAMP, WFC2-MRAMP, WFC2-ORAMP, WFC1-IRAMPQ, WFC1-MRAMPQ, WFC2-ORAMPQ	See Table 11.2.	CR-SPLIT, GAIN, AUTOIMAGE, FLASH
ACS/SBC	ACCUM	SBC, SBC-FIX	See Table 11.5.