Glossary and
Acronym List

The following terms and acronyms are used in this Handbook.

 

ACCUM: Accumulate readout mode for NICMOS observations.

ACS: Advanced Camera for Surveys.

ACQ: Observing mode in which the brightest source is located in a sub-array and the telescope is repositioned to place the source behind the coronagraphic hole.

A-D: Analog to digital.

ADC: Analog to digital converter.

ADU: Analog digital unit; 1 ADU = 1 DN.

ASCS: Aft Shroud Cooling System.

APT: The Astronomer’s Proposal Tool.

Breathing: Short term focus oscillations due to thermal variations on an orbital time scale.

BRIGHTOBJ: Bright object observing mode.

CALNICA: Primary NICMOS calibration task.

CALNICB: Secondary NICMOS calibration task used after CALNICA on those exposures which comprise an association.

CCD: Charge-coupled device. Solid-state, light detecting device.

CDBS: Calibration Data Base System; system for maintaining reference files and tables used to calibrate HST observation datasets.

Chop: A spatial offset of up to 1440 arcsec of the aperture with respect to the target, intended for the measurement of the background at one or more locations significantly removed from the target pointing.

COS: Cosmic Origins Spectrograph.

COSTAR: Corrective Optics Space Telescope Axial Replacement.

CP: Call for Proposals.

CPL: Capillary Pumped Loop.

CR: Cosmic Ray.

CVZ: Continuous Viewing Zone.

CP: Contact Scientist.

Dither: A small spatial offset (no more than 40 arcsec) of the position of the target in the aperture between successive observations.

DN: Data Number.

Drizzle: A technique (and STSDAS task) for the linear image reconstruction of dithered images.

DSS: Digitized Sky Survey.

DQ: Data Quality.

DQE: Detector Quantum Efficiency.

ESM: Electronic Support Module.

ETC: Exposure Time Calculator.

FAQ: Frequently Asked Questions.

FDA: Field Divider Assembly.

FET: Field Effect Transistor.

FGS: Fine Guidance Sensors.

FITS: Flexible Image Transport System. A generic IEEE- and NASA-defined standard used for storing image data.

FOC: Faint Object Camera.

FOM: Field Offset Mirror (or mechanism).

FOS: Faint Object Spectrograph.

FOV: Field Of View.

FPA: Focal Plane Array.

FSW: Flight Software.

FTP: File Transfer Protocol; basic tool used to retrieve
files from a remote system.

FWHM: Full Width at Half Maximum.

GHRS: Goddard High Resolution Spectrograph.

GO: General Observer.

GS: Guide Star.

GSC: Guide Star Catalog.

GSFC: Goddard Space Flight Center.

GTO: Guaranteed Time Observer.

HOST: HST Orbital Systems Test.

HSP: High Speed Photometer.

HST: Hubble Space Telescope.

ICD: Interface Control Document; defines data structures used between software or systems to ensure compatibility.

IDT: Instrument Development Team.

IR: Infrared.

IRAF: Image reduction and analysis system. The system on which STSDAS is built.

IRAS: Infrared Astronomical Satellite.

ISR: Instrument Science Report.

Jansky: The standard flux unit for NICMOS documentation and software.
1 Jy = 1.0 â 10-26 W/m2/Hz = 1.0 â 10-23 erg/s/cm2/Hz.

Jy: Jansky.

K: Degrees Kelvin.

LSF: Line Spread Function.

MLI: Multi-Layer Insulation.

MOS: Multi-Object Spectroscopy.

Mosaic: A single image produced by combining the multiple images contained in a NICMOS associated data set; this combination is done by the STSDAS task calnicb.

MULTIACCUM: Multiple-accumulate readout mode for NICMOS observations.

MultiDrizzle: Automates and simplifies the detection of cosmic rays and the combination of dithered observations using the Python scripting language and PyRAF (Koekemoer et al., 2002 HST Calibration Workshop, p337).

NCC: NICMOS CryoCooler.

NCS: Nicmos Cooling System.

NICMOS: Near-Infrared Camera and Multi-Object Spectrometer.

NIR: Near Infrared.

NUV: Near ultraviolet.

OPUS: OSS and PODPS Unified Systems.

OSS: Observation Support System.

OTA: Optical Telescope Assembly.

OTFR: On-The-Fly Reprocessing.

PACOR: Packet process.

POD: Packetized Observation Data.

PAM: Pupil Alignment Mirror (or mechanism).

PC: Program Coordinator.

PCE: Power Conversion Electronics.

PED: Proposal editor.

Phase I: The process of submitting a proposal for HST observations.

Phase II: The process of designing accepted HST observing proposals.

PI: Principal Investigator.

PODPS: Post-Observation Data Processing System.

PSF: Point Spread Function.

QE: Quantum Efficiency.

RA: Right Ascension.

RMS: Root Mean Square.

RTO: Reuse Target Offset.

SAA: South Atlantic Anomaly.

SAM: Small Angle Maneuver.

SAMP-SEQ: Pre-defined sample sequence (readout times) for NICMOS observations.

SLTV: System Level Thermal Vacuum (testing phase).

SM: Servicing mission.

SMOV: Servicing Mission Orbital Verification.

S/N: Signal-to-Noise ratio. Also seen as SNR.

SSR: Solid State Recorder.

STAN: Space Telescope Analysis Newsletter.

StarView: The user interface to the HST data archive.

ST-ECF: Space Telescope European Coordinating Facility.

STIS: Space Telescope Imaging Spectrograph.

STScI: Space Telescope Science Institute.

STSDAS: Space Telescope Science Data Analysis System. The complete suite of data analysis and calibration routines used to process HST data.

TAC: Telescope Allocation Committee.

TEC: Thermal Electrically Cooled shells.

TinyTim: Program which produces simulated HST point spread functions.

URL: Uniform resource locator; address for WWW.

UV: Ultraviolet.

VCS: Vapor Cooled Shield.

WFPC: Wide Field/Planetary Camera.

WFPC2: Wide Field Planetary Camera 2; replacement for WF/PC installed during first servicing mission of December 1993.

WWW: World Wide Web; hypertext-oriented method for finding and retrieving information over the Internet.

YSO: Young Stellar Object.