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ISDCCDCI
INTEGRAL Science Data Centre
Glossary of ISDC Terms

This page is a list, in alphabetical order and with explanations, of acronyms and technical terms frequently used at the ISDC.


Jump to a Letter or an Acronym  

ACA
The Automatic Calibration Analysis (ACA) is designed as an automatic process within the ISDC ScW Pipeline to simplify routine calibrations.
AO
The release of an INTEGRAL Announcement of Opportunity (AO) informs the astronomical community that prospective INTEGRAL observers are now welcome to submit their proposals to the ISOC.
ARF
The Ancillary Response Function (ARF) expresses the effective area of the instrument in surface units (cm2) as a function of photon energy.
CCB
The Configuration Control Board (CCB) is composed of three ISDC staff members which decide the modifications to be done in response to the received software problem reports (SPR) and software change requests and extra wishes (SCREW).
CFITSIO
C FITS Input/Output (CFITSIO) is a software library for reading and writing data files in FITS format from within C.
Co-I
A Co-Investigator (Co-I) is a person among the group of scientists which is involved, together with the Principal Investigator (PI), in a given observing proposal.
CTS
The Coding and Testing Standards (CTS) define in detail how the ISDC software shall be written and tested.
CVS
The Concurrent Version System (CVS) is a version control system used to maintain a software repository including past versions, information about who modified them and when, and so on.
DAL
The Data Access Layer (DAL) is a software library used to manipulate (create, write, read and manage) scientific data.
DAL3
The 3rd level of the Data Access Layer (DAL3) is an INTEGRAL specific software library built on top of the common DAL (2nd level). It has the purpose to simplify and standardize access to the data in the course of the scientific analysis.
DOL
The Data Object Location (DOL) specifies the location of a DAL object, both by the FITS file name and its extension. For instance, ``/isdc/dev/xxx.fits[2]'' is a DOL, while ``xxx.fits'' is simply the name of a FITS file.
ESAC
The European Space Astronomy Centre (ESAC), previously called VILSPA, near Madrid, Spain is the new location of the INTEGRAL Science Operations Centre (ISOC).
FITS
The Flexible Image Transport System (FITS) is a data format widely used in astronomy. It can store multi-dimensional arrays (1-D spectra, 2D images or 3-D data cubes) and 2-dimensional tables. A single FITS file can contain multiple data sets, each in a separate extension (e.g. ``xxx.fits[1]'' is the extension No. 1 of the ``xxx.fits'' file).
FOV
The Field of View (FOV) of a coded-mask instrument is usually divided in two distinct parts: the Partially Coded FOV (PCFOV) and the Fully Coded FOV (FCFOV).
FTE
A Full Time Equivalent (FTE) denotes a job for a single person working at full-time or for a group of part-time workers doing together an equivalent work.
FTOOLS
FTOOLS is a general package of software to manipulate FITS files.
fv
The fits viewer (fv) is an interactive program with a graphical user interface for viewing, plotting and editting any FITS file.
GTI
A Good Time Interval (GTI) is a part of an observation defined as being of good quality according to the value of one or several parameters (e.g. background level, temperature of the instrument, etc.)
GUI
Graphical User Interface (GUI)
HK
Housekeeping (HK) data consist of technical information related to the instruments, as for instance instrumental temperatures or voltages.
IBIS
The Imager on Board the INTEGRAL Spacecraft (IBIS) is a coded mask instrument designed for high angular resolution (12 arcmin, but source location down to 1 arcmin) imaging in the energy range from ~20 keV to ~10 MeV. Its total field of view is ~30 x 30 degrees with an uniform sensitivity within the central ~10 x 10 degrees.
IBAS
The INTEGRAL Burst Alert System (IBAS) is designed to detect and locate gamma-ray bursts in the field of view of the instruments within a few seconds.
IJD
The INTEGRAL Julian Date (IJD) is the fractional number of days since January 1st, 2000 in terrestrial time (TT) expressed by a double precision real (IJD = JD - 2,451,544.5).
INTEGRAL
The INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) is a mission of the European Space Agency (ESA). The INTEGRAL satellite was launched by a Russian PROTON rocket on October 17, 2002.
IRAF
The Image Reduction and Analysis Facility (IRAF) is a general purpose software system for the reduction and analysis of astronomical data. IRAF is written and supported by a group of the National Optical Astronomy Observatories (NOAO) in Tucson, Arizona.
IREM
The INTEGRAL Radiation Environment Monitor (IREM) is mounted on the INTEGRAL spacecraft for continuous monitoring of the ionizing radiation in space.
ISDA
The ISOC Science Data Archive (ISDA) was opened to external users on 14 July 2005. It can be accessed at: http://integral.esac.esa.int/isda.
ISDC
The INTEGRAL Science Data Centre (ISDC) is the link between the scientific output of the instruments on board INTEGRAL and the astronomical community. It has the task to receive, analyse and archive all INTEGRAL data and to distribute them to the observers worldwide. The ISDC is located in Versoix, near Geneva, Switzerland.
ISGRI
The INTEGRAL Soft Gamma-Ray Imager (ISGRI) is the top layer of the IBIS detection plane. It consists of an array of 128 x 128 Cadmium Telluride (CdTe) square pixels (4 mm x 4 mm each) and covers the energy range from ~20 keV to a few hundred keV.
ISOC
The INTEGRAL Science Operations Centre (ISOC) is responsible for the definition of scientific operations including the instrument configuration for each observation, the mission planning and the implementation of the observing programme. The ISOC is moved from ESTEC to ESAC near Madrid, Spain.
ISSW
Instrument Specific Software (ISSW) denotes software executables written by the instrument teams to be integrated in the ISDC data analysis system.
ISWT
The INTEGRAL Science Working Team (ISWT) has the task to maximize the scientific return of the INTEGRAL mission. Its members are the scientists which are the most involved in the development of the INTEGRAL mission (e.g. PIs of the instruments and mission scientists).
JEM-X
The Joint European X-Ray Monitor (JEM-X) consists of two identical coded mask instruments designed for X-ray imaging in the range of 3-35 keV with an angular resolution of 3 arcmin.
MOC
The Mission Operations Centre (MOC) is responsible for spacecraft operations and maintenance tasks. It performs the uplink of the observation plan to the satellite in orbit, gathers the raw science data from INTEGRAL and sends them to the ISDC. The MOC is located at ESOC, the European Space Operations Centre, in Darmstadt, Germany.
MR
The Monthly Report (MR) of the ISDC is an internal review on what happened during the last month and on the work which was achieved.
NRT
Near Real Time (NRT) data handling is performed continuously at nearly the same speed as the data flow arrives at the ISDC.
OBT
The On-Board Time (OBT) is expressed by an 63-bit integer in units of 2-20 seconds.
OCA
The Off-line Calibration Analysis (OCA) is performed interactively at the ISDC to complete the automatic calibration analysis (ACA).
OMC
The Optical Monitoring Camera (OMC) for INTEGRAL is an optical (500-850 nm and V filter) CCD (1024 x 2048 pixels) camera with a field of view of 5 x 5 degrees. It can detect optical counterparts of the prime targets of IBIS and SPI up to a visual magnitude of mV = 19.7.
OG
An Observation Group (OG) is defined as a collection of science windows (ScW) belonging to the same observation. ScWi and OGi (i=1, 2 or 3) characterize different levels i of the processing steps the data have undergone.
OSA
The Off-line Scientific Analysis (OSA) comprises all advanced scientific analyses performed interactively by astronomers worldwide.
OSim
The Observation Simulator (OSim) is a software package developed by the ISDC to simulate INTEGRAL observations. It is able to simulate IBIS, SPI and JEM-X scientific data.
OSM
The Operation Status Monitoring (OSM) is performed at the ISDC to monitor the housekeeping data, the science data and the auxiliary data. There is an automatic OSM within the ScW pipeline and an interactive OSM with some utility programs and several displays.
OTE
The Observation Time Estimator (OTE) is a tool developed at the ISOC to allow proposers to estimate the appropriate observation time for their proposal.
PI
The Principal Investigator (PI) of a proposal or of an observation is the person representing a group of scientists (the Co-Is) submitting all together a proposal for an observation.
PICsIT
The Pixellated CsI Telescope (PICsIT) is the bottom layer of the IBIS detection plane. It consists of an array of 64 x 64 scintillators of Caesium Iodide (CsI) and covers the energy range from ~150 keV to ~10 MeV.
PIF
The Pixel Illumination Factor (PIF) is a number between 0 and 1, which expresses the theoretical degree of illumination of each pixel of the detector plan of a coded-mask instrument. The PIF is used to derive the spectrum of sources observed with a coded-mask instrument and is calculated on the basis of the position and the relative intensity of each source in the field of view.
PIL
The Parameter Interface Layer (PIL) is a ISDC software library which accesses and manages input parameters for the analysis executables. The purpose of PIL is to enable ISDC applications to access IRAF compatible parameter files.
PGT
The Proposal Generation Tool (PGT) is a tool developed at the ISOC to prepare INTEGRAL proposals. It has to be downloaded in order to run on the proposer's machine.
PP
The Preprocessing (PP) is the first data processing step at the ISDC after data receipt (DR). Its main job is to reformat, sort and reorganise the telemetry data into FITS data files corresponding to distinct science windows (ScW).
QLA
The Quick-Look Analysis (QLA) is a scientific analysis performed at the ISDC within a few hours of data receipt. It consists of comparing the INTEGRAL data with the expected position and flux of known sources, in order to rapidly detect bright transient sources, large flux changes in known sources and instrument anomalies.
RIL
The Reporting Interface Layer (RIL) is a ISDC software library which handles the reporting of errors, warnings, alerts and general log messages.
RMF
The Redistribution Matrix File (RMF) is an instrumental response file that describes how photons of different energy are redistributed into the various energy channels of the instrument.
ROOT
ROOT (its not an acronym) is an object-oriented data analysis framework developed at CERN. It is based on C++ and is designed to handle and analyse large amounts of data in a very efficient way. ISDC ROOT and AstroROOT are extensions to ROOT developed at the ISDC for specific tasks.
RP
The Reference Platform (RP) denotes the configuration of hardware and operating system software on which all other software is expected to execute.
RSDC
The Russian (INTEGRAL) Science Data Centre (RSDC) is based in Moskow.
SA
The Standard Analysis (SA) is an automatic scientific analysis performed at the ISDC within three weeks of data receipt. It results in deconvolved images of the gamma-ray sky, spectra of individual sources and light-curves of variable objects.
SCREW
Software Change Requests and Extra Wishes (SCREW) can be proposed by software developers to modify or add something to existing ISDC software.
ScW
A Science Window (ScW) is a unit of continuous observing time used by the ISDC sytem to archive and process data. It is the basic unit of INTEGRAL observations and corresponds, under normal dithering operations, to a pointing or a slew of the spacecraft. A ScW usually groups more than hundred distinct data structures describing different types of data, for instance event lists or histograms.
SLALIB
SLALIB (its not an acronym) is a software library used by writers of positional-astronomy applications. Most SLALIB routines are concerned with astronomical position and time, but a number have wider trigonometrical, numerical or general applications.
SPI
The Spectrometer on INTEGRAL (SPI) is a coded mask instrument designed for high energy resolution (2 keV at 1 MeV) spectroscopy of gamma-ray sources in the 20 keV to 8 MeV range. It consits of an array of 19 hexagonal high-purity Germanium detectors. The field of view is of 16° in diameter with an angular resolution of 2°.
SPR
Software Problem Reports (SPR) are evaluated and discussed by the ISDC configuration control board (CCB).
TAC
The Time Allocation Committee (TAC) evaluates the quality of each proposal and defines which observations will actually be performed by the INTEGRAL satellite.
TBC
To Be Confirmed (TBC)
TBD
To Be Defined (TBD)
TBW
To Be Written (TBW)
TIMM
The INTEGRAL Mass Model (TIMM) is a detailed Monte Carlo based simulation of the INTEGRAL spacecraft and its scientific instruments. It is used to estimate the response of INTEGRAL to the particle flux it will encounter in orbit.
TM
The Telemetry (TM) denotes the whole data stream sent to earth by the INTEGRAL spacecraft.
TOO
A Target of Opportunity (TOO) is a special type of observation, which is only performed in the case of a particular event. A trigger for a TOO observation could be, for instance, a supernova explosion or an outburst in a flaring source.
TVP
The Target Visibility Predictor (TVP) is a tool developed at the ISOC to allow proposers to check the time periods during which a given target (source) can be observed by INTEGRAL.
UM
The User Manual (UM) describes a given tool and explains how to use it.