LBT Data Archive: keyword definitions

The LBT data archive needs some reliably-specified information in the image headers to know how to keep track of the data and where to send it amongst the distributed archive machines in the US, Germany, and Italy. The primary FITS header keywords needed, and their specification, include:

  • PARTNER - Specified the partner or partners for whom the data were taken
  • OBSERVER - Name of the responsible person at the telescope when data were taken
  • IMAGETYP or DATATYPE - Identifies data as either science data (OBJECT, or SCIENCE) or calibration (DARK, BIAS, etc.)
  • PI_NAME - Identifies the project principle investigator (arbitrary user-defined string)
  • PROPID - String identifying the project to the PI (arbitrary user-defined string)
  • OBJECT - Identifies the name of the source being observed (arbitrary user-defined string)

PARTNER

The PARTNER Keyword tells the archive how to distribute the data across the mirrors in Germany and Italy. This keyword can assume any of the following single string values:

Primary partners: OSURC, LBTB, INAF, AZ

Telescope Commissioning and Technical Obs: LBTO

Instrument Engineering and Commissioning: COMMISSIONING (the instrument is specified in the INSTRUME keyword)

Calibration data (darks, twilight flats, etc.): CALIBRATION

Unspecified default: NOPARTNER

Science Demonstration Time: LBTSDT

Implementation of the PARTNER string must follow these rules:

  • The default is NOPARTNER
  • Must be able to be set in the UI and scripting, with script values overriding the UI
  • ALL CAPS in the image headers, but optionally should accept any capitalization in UI/scripts
  • Accept comma-separated (no spaces) multiple partners, e.g.: OSURC,INAF, with any combination of valid single partner identifiers
  • Data labeled NOPARTNER will be held undistributed until properly identified

A complete set of the data taken at the LBT is kept in two locations, at the telescope and in Tucson, and on three machines, two at the LBT and one in Tucson. The PARTNER keyword will be used to determine distribution of the data to the archive mirrors in Germany and Italy as:
  • Germany mirror: receives all LBTB and LBTSDT data, plus COMMISSIONING data from Lucifer and Linc, and all CALIBRATION data from all partner observing blocks.
  • Italy mirror: receives all INAF and LBTSDT data, COMMISSIONING data from LBC, and all CALIBRATION data from all partner observing blocks.

OBSERVER

The current implementation of the string in the OBSERVER keyword in LBC data has taken the place of PARTNER (through March 2010), but this must be corrected. Implementation in LUCIFER and subsequent instrumentation at the LBT should follow these rules:

  • The default is the instrument name
  • Must be set either within the UI or on start-up of the UI, but not in scripts
  • Arbitrary string, can include comma-separated values but no spaces
  • The responsible observer present at the telescope should set this to their name

The intent is to identify at least the lead observer present at the telescope. If questions arise when the PI is working on the data, they will know who to contact for observing-related information.

IMAGETYP (DATATYPE)

All calibration data (arcs, flats, bias, darks) taken during science observations will be distributed to all mirrors and available to all partners without restriction. The primary way this is defined in the image headers is with the FITS standard keyword IMAGETYP (can optionally use DATATYPE instead of IMAGETYP) keyword. The IMAGETYP keyword is set following these rules:

  • Valid entries: OBJECT, SCIENCE, SKY, STD, FOCUS, BIAS, DARK, ZERO, FLAT, ARC, COMP, CALIB, ILLUM, and FRINGE
  • Header values should be in ALL CAPS
  • The default is OBJECT
  • Should be set automatically based on instrument configuration, although this would not cover all possibilities. A sufficient subset would be if a blank filter or shutter remains closed then set to DARK, if open and (e.g. for LUCIFER or MODS) a calibration unit is in, set to CALIB, otherwise set to OBJECT
  • Able to set in UI and scripts to override the automatic setting. For example, the observer needs to be able to differentiate between science targets and calibration data (e.g. photometric imaging standards or telluric spectroscopic standards) with the scripts prepared in advance of the observations

PI_NAME

The intent of the PI_NAME string is to identify at least the principle investigator (PI) of the science project for which these data are being taken. Access to data in the archive can be controlled at a level below PARTNER by using the PI_NAME. Implementation of the PI_NAME string at the LBT should follow these rules:

  • The default is NOTSPECIFIED
  • Must be able to be set in scripts, overriding values (optionally) set in the UI
  • Arbitrary string, can include comma-separated values but no spaces
  • The person leading this science project should set this to their name

PROPID

The intent of the PROPID string is identify the observer program ID approved from any TAC partner. It's strong correlated with the PI-NAME keyword. This is included as a convenience for the investigators in retrieving related data from the archive, and allow people or group of working retrieve directly their own data. Implementation of the PROPID string at the LBT should follow these rules:

  • The default is NOTSPECIFIED
  • Must be able to be set in scripts, overriding values (optionally) set in the UI
  • Arbitrary string, can include comma-separated values but no spaces
  • The TAC or person leading this science project should set this to some unique identifier for this project

OBJECT

The OBJECT string identifies the source being observed in sufficient detail to ....

  • The default is NOTSPECIFIED
  • Set based on entry in a user-supplied catalog of sources
  • Must be able to be set in scripts, overriding any current value from a catalog or in the UI
  • Arbitrary string, can include comma-separated values but no spaces
  • The person leading this science project should set this appropriate for the source being observed

-- DavidThompson - 18 Mar 2010
Topic revision: r6 - 06 May 2010, DavidThompson
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