The CDS quicklook data structure

All the information contained in the FITS data files is loaded into an IDL structure, here called the quicklook data structure.

will show the top level structure: 

** Structure <408be008>, 54 tags, length=4966176, refs=1:
   QL_ID           DOUBLE       9.6443517e+08
   QL_NO           INT             19
   HDRTEXT         STRING    Array[492]
   HEADER          STRUCT    -> HDRX Array[1]
   DETDATA         FLOAT     Array[72, 120, 143]
   DETDESC         STRUCT    -> NISX3 Array[4]
   BACKGROUND      STRUCT    -> CDS_BACK_120 Array[1]
   WAVECAL         STRUCT    -> NIS_WAVECAL Array[1]
   DEL_TIMEDATA    DOUBLE    Array[120]
   DEL_TIMEDESC    STRUCT    -> AUX1 Array[1]
   INS_XDATA       FLOAT     Array[120]
   INS_XDESC       STRUCT    -> AUX1 Array[1]
   INS_YDATA       FLOAT     Array[120]
   INS_YDESC       STRUCT    -> AUX1 Array[1]
   OPSLBITSDATA    BYTE      Array[120]
   OPSLBITSDESC    STRUCT    -> AUX1 Array[1]
   OPS_LDATA       INT       Array[120]
   OPS_LDESC       STRUCT    -> AUX1 Array[1]
   OPSRBITSDATA    BYTE      Array[120]
   OPSRBITSDESC    STRUCT    -> AUX1 Array[1]
   OPS_RDATA       INT       Array[120]
   OPS_RDESC       STRUCT    -> AUX1 Array[1]
   SLITBITSDATA    BYTE      Array[120]
   SLITBITSDESC    STRUCT    -> AUX1 Array[1]
   SLIT_POSDATA    INT       Array[120]
   SLIT_POSDESC    STRUCT    -> AUX1 Array[1]                               
   MIR_POSDATA     BYTE      Array[120]
   MIR_POSDESC     STRUCT    -> AUX1 Array[1]
   .
   .
   .
   .

whereas

will show most of the details needed for data analysis. 

** Structure HDRX, 76 tags, length=664:
   ANGLE           DOUBLE           0.0000000
   CATEGORY        STRING    'Science'
   CMP_NAME        STRING    ''
   CMP_NO          LONG                 1
   COMP_ERR        BYTE         0
   COMP_ID         LONG                 1
   COMP_OPT        LONG                 0
   DATASRC         STRING    '0'
   DATE            STRING    '1998-04-13'
   DATE_END        STRING    '1996-04-29T03:14:03.318Z'
   DATE_OBS        STRING    '1996-04-29T02:36:29.678Z'
   DETECTOR        STRING    'NIS'
   DW_ID           LONG                28
   EV_ENAB         BYTE         0
   EXPCOUNT        LONG               120
   EXPTIME         FLOAT           15.0000
   .
   .
   .

Many routines are provided to make retrieval of information from the QLDS easier and more intuitive.

So

and give the same result, but the latter is supposed to be easier to remember!

A thorough 'surf' through the details of the QLDS is possible using

Be prepared for a bit of a wait while it loads.