DST format

One of the foreign formats is called the `Figaro format'-in fact it is Figaro's old DST format. These days Figaro uses NDF format, but that was the case only since version 3.0.

Like NDF, DST is a specification of an HDS object hierarchy. Only the hierarchy is different, the same information is in different places.

The NDF shown in the section on the NDF format would look in DST format like this:

A_FILE  <FIGARO>

   Z              <IMAGE>         {structure}
      UNITS          <_CHAR*32>      'A/D numbers per exposure'
      LABEL          <_CHAR*32>      'OBJECT - DARK'
      FLAGGED        <_LOGICAL>      TRUE
      DATA(310,19)   <_REAL>         1655.552,1376.111,1385.559,1746.966,
                                     ... 1513.654,1465.343,1446.902,*,*,*,*,*
      ERRORS(310,19) <_REAL>        9.330093,4.624712,1.043125,3.801913,
                                     ... 16.92331,11.49692,10.9114,0,0,0,0,0

   X              <AXIS>          {structure}
      LABEL          <_CHAR*32>      'Estimated wavelength'
      UNITS          <_CHAR*32>      'microns'
      DATA(310)      <_REAL>         1.85115,1.852412,1.853675,1.854938,
                                     ... 2.237606,2.238869,2.240132,2.241395

End of Trace.

DST stores errors instead of variances. There is no `a_file.Y' structure, since the second axis has default pixel coordinates. In DST format only non-default axes must actually exist.

There is also no quality array, instead the data array has bad values interspersed with good values. This is not a property of the DST format itself, but the way the format conversion treats a quality array.