CR-SPLIT: Division of a CCD exposure into shorter exposures to be used for cosmic ray rejection
CTE: Charge transfer efficiency
CVZ: Continuous viewing zone
DN: Data number
ETC: Exposure Time Calculator. ETCs are Web-based tools which can be accessed through the ACS Web pages.
ERO: Early release observations
FGS: Fine Guidance Sensors
FOS: Faint Object Spectrograph
FOV: Field of view
FTP: File Transfer Protocol. Basic tool used to retrieve files from a remote system. Ask your system manager for information about using FTP.
FUV: Far ultraviolet (~912 to 2000 Å)
FWHM: Full width at half maximum
GALEX: Galaxy Evolution Explorer
GHRS: Goddard High-Resolution Spectrograph
GO: General Observer
GSC: Guide Star Catalog
GSCII: Guide Star Catalog II
GTO: Guaranteed Time Observer
Help Desk: Facility for getting help on HST related topics via email. help@stsci.edu.
HRC: High Resolution Channel
HST: Hubble Space Telescope
IDT: Investigation Definition Team
IR: Infrared
IRAF: Image Reduction and Analysis System. The environment in which STSDAS operates.
ISR: Instrument Science Report
IUE: International Ultraviolet Explorer Satellite
K: Degree Kelvin
L-flats: Low Frequency Variations Flats
LMC: Large Magellanic Cloud
MAMA: Multi-Anode Microchannel Array
MCP: Microchannel Plate
MPP: Multi Pinned Phased, a CCD mode that reduces dark current rate
NICMOS: Near-Infrared Camera and Multi-Object Spectrograph
NUV: Near ultraviolet (~2000 to 4000 Å)
OTA: Optical Telescope Assembly
PASP: Publications of the Astronomical Society of the Pacific
PC: Program Coordinator
Phase I proposal: A proposal for observing time on HST
Phase II program: An approved HST program; includes precise detail of how program is to be executed
PI: Principal investigator
P-flats: pixel-to-pixel high-frequency flats
PRF: Pixel Response Function
PSF: Point-spread function.
PyRAF: version of IRAF implemented in the Python language
QE: Quantum Efficiency
QEH: Quantum Efficiency Hysteresis
Quadrant: Section of detector that is read-out by an amplifier. For WFC, there are 4 amplifiers, two for each detector, so each amplifier reads one 2048 x 2048 pixel quadrant.
RA: Right Ascension
RAS: HST simulator used in ground tests to accurately simulate the full field OTA illumination, and is used to calibrate HST instruments. Also know as RAS/HOMS, the Refractive Aberrated Simulator/Hubble Opto-Mechanical Simulator.
reference file: data file containing ACS parameters or calibration information which is used by the calibration pipeline
rms: Root mean square
RQE: Responsive Quantum Efficiency
SAA: South Atlantic anomaly
SBC: Solar-Blind Channel
SDSS: Sloan Digital Sky Survey
SITe: Scientific Image Technologies; company that designed the ACS CCDs
SLIM: Slitless Spectroscopy Simulator
SMOV: Servicing Mission Observatory Verification
S/N: Signal-to-noise ratio
SNAPSHOT: Short exposures taken during unused blocks of telescope time.
ST-ECF: Space Telescope European Coordinating Facility
STAN: Space Telescope Analysis Newsletter
STIS: Space Telescope Imaging Spectrograph
STScI: Space Telescope Science Institute
STSDAS: Space Telescope Science Data Analysis System. The complete suite of IRAF data analysis and calibration routines used to process HST data.