Spitzer Documentation & Tools
IRAC Instrument Handbook

Appendix E.          Acronyms

ADC

Analog-to-Digital Converter

AOR

Astronomical Observation Request - an individual observation.

AORKEY

Astronomical Observation Request Key - a unique numerical identification of an observation.

AOT

Astronomical Observation Template - the IRAC observing mode.

BCD

Basic Calibrated Data, the Level 1 data product from each DCE that has been pipeline-processed and is fully calibrated.

CBCD

Corrected Basic Calibrated Data. This should be the starting point for further scientific analysis in

most cases.

Campaign

Unbroken time period when an instrument is powered on. Most instrument IRAC campaigns are

expected to be on the order of one week in length.

CTE

Charge Transfer Efficiency.

DCE

Data Collection Event, for IRAC a single 256x256 pixel image from a single detector. 

 

DN

Data Number.

FET

Field Effect Transistor.

FOS

    Flight Operations System.

FPA

Focal Plane Assembly, housing one IRAC detector.

InSb

Indium Antimonide, the detector material used in the short wavelength channels of IRAC (1 and

2).

IOC

In-Orbit Checkout, the two-month long testing period of the telescope following its launch.

ISSA

IRAS Sky Survey Atlas.

JPL

Jet Propulsion Laboratory

MIC

Multiple Instrument Chamber.

PAO

Period of Autonomous Operation, the interval between ground contacts for uplinking commands

and downlinking data, normally 12-24 hours.

PCS

Pointing Control System.

PRF

Point Response Function. The PRF is essentially the convolution of a box the size of the image

pixel with the PSF.

ROIC

Read-Out Integrated Circuit. It is the chip that contains the multiplexer (column and row scanners

and the buses), the unit cell amplifiers, and the output amplifiers. The chip containing the detector

diodes is bonded to it. It is often called simply the “mux."

SAO

Smithsonian Astrophysical Observatory, Cambridge, MA.

SSC

Spitzer Science Center, Caltech, Pasadena, CA.

Si:As

Arsenic-doped Silicon, the detector material in the IRAC long-wavelength channels (3 & 4).

SV

Science Verification, a 35-day period after the IOC during which the science instruments and their observational modes were commissioned.

SWIRE

Spitzer Wide Area Infrared Survey.

WCS

World Coordinate System.