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Access to VIRGO data

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Where can we get VIRGO data?

The best place to start is to go to the public SOHO data archive where most data from this wonderful spacecraft can be found.

How do we read the data?

There are up to now three kind of file:
  • YYMMDD_1.DO1
  • YYMMDD_1.PO1
  • YYMMDD_1.S02
  • YYMMDD_1.LO1
  • The YYMMDD_1.DO1 is related to the data acquired on the day DD/MM/YY by the Diarad instrument (radiometer). One data per 3 minutes.

    The YYMMDD_1.PO1 is related to the data acquired on the day DD/MM/YY by the PMO6 instrument (radiometer). One data per 3 minutes.

    The YYMMDD_1.S02 is related to the data acquired on the day DD/MM/YY by the SPM instrument (3-color radiance instrument). One data per 1 minute at 402 nm, 500 nm and 862 nm.

    The YYMMDD_1.L01 is related to the data acquired on the day DD/MM/YY by the LOI nstrument (16-pixel instrument at 500 nm). One data per 1 minute/pixel at 500 nm.

    The data can be read with IDL using the fits routines that can be found on the net (if you have any trouble please let me know). The typical code to be
    used is the following:

    IDL> outdata=readfits('YYMMDD_1.L00',header_name,/exten)
    IDL> keyword=ftget(header_name,outdata,'keyword')

    These two statements should allow one to derive the required data according to the keywords. Hereafter is the name of the keywords and their description.
     

    DIARAD 2 keywords:

  • SOLAR_CT: Solar constant
  • STATUS : Status of the instrument
  • PMO6 2 keywords:

  • PMO6_VA: Solar constant A
  • PMO6_VB: Solar constant Back-up
  • SPM 9 keywords:

  • RED: red photmeter (802 nm)
  • GREEN: green photometer (500 nm)
  • BLUE: blue photometer (402 nm)
  • DQ1: ?
  • BCKUP: ?
  • DQ2: ?
  • MODE: ?
  • SEQ: ? A
  • CTINST: name of the active instrument (the whole instrument is doubled)
  • LOI 20 keywords:

    PIXEL1 to PIXEL 16: 16 pixels of the array photodiode
    QFLAGSC: Quality flag of the 1 to 12 pixels
    QFLAGGU: Quality flag of the 13 to 16 pixels (associated with the guiding)
    DIAM_EW: EW diameter of the solar image
    DIAM_NS: NS diameter of the solar image

    If you have any questions related to the VIRGO instrument, I will be happy to oblige. How does it sound?
     

    Last updated by Thierry Appourchaux on November 15, 2004