13.1 Introduction to WFC3

The Instrument Configurations and Operating Modes described in the following section are used to define exposures on the Visit and Exposure Specifications. The legal Visit and Exposure Specifications entries are summarized in the following sections. More complete descriptions of Instrument Configurations, Modes, Apertures, Spectral Elements, Detector Characteristics, etc. are available in the WFC3 Instrument Handbook.

Note that many of the Optional Parameters have default values; in such cases, an entry for an Optional Parameter in the Visit and Exposure Specifications is necessary only if it is desired to override the default value. The physical units of Optional Parameter quantities are always implicit and should never be entered by the observer.

Table 13.1 lists the permitted WFC3 Instrument Configurations, Operating Modes, Apertures, Spectral Elements, and Optional Parameters.

Table 13.1: Supported Instrument Parameters for WFC3

Config	Mode	Aperture	Spectral Elements	Optional Parameters
WFC3/UVIS	ACCUM	See Table 13.2: Apertures for WFC3/UVIS	See Table 13.5	CR-SPLIT, BIN, INJECT , FLASH
WFC3/IR	MULTI ACCUM	See Table 13.3: Apertures for WFC3/IR	See Table 13.6	SAMP-SEQ, NSAMP