12.1 Introduction to WFC3
HST observations with WFC3 are specified using the Astronomer's Proposal Tool (APT), and this article provides instructions for completing those observations.
Boldface type indicates the name of an APT parameter or a value for a parameter.
Black text indicates an important note.
Magenta text indicates available but unsupported parameters (requires prior approval from STScI).
Red text indicates restricted parameters (for STScI use only).
Brown text indicates text file parameters.
Items in brackets - <value> - are required values.
Items in square brackets - [<value>] - are optional.
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 12.1 lists the permitted WFC3 Instrument Configurations, Operating Modes, Apertures, Spectral Elements, and Optional Parameters.
Table 12.1: Supported Instrument Parameters for WFC3
CR-SPLIT, BIN, FLASH,
SAMP-SEQ, NSAMP, GAIN
Version Cycle 30 August 2022
Fix links in Table 12.1