[fitsbits] Extended Comment Period on 2 FITS Proposals

[John E. Davis]

On Tue, 02 Nov 2004 17:39:17 -0500, Bob Garwood <bgarwood at nrao.edu>
wrote:
>I think it would be more useful in that case if the TDIM values for that 
>column could be expressed as a column itself instead of a keyword.  e.g. 
>if the variable column in question is column 05 then somewhere you'd 
>have another column with a TTYPE value of "TDIM05".

For what it is worth, the Chandra HRC-S QEU files (in the CALDB)
contain binary tables with columns such as:

   TFORM1  = '1I      ' /Integer*2 (short integer)
   TTYPE1  = 'REGIONID' /Label for column 1
   TFORM2  = '23E     ' /Real*4 (floating point)
   TTYPE2  = 'ENERGY  ' /Label for column 2
   TFORM3  = '1PE(44574)' /Real*4 (floating point), variable length
   TTYPE3  = 'QEU     ' /Label for column 3
   TFORM4  = '1PE(44574)' /Real*4 (floating point), variable length
   TTYPE4  = 'SYS_MIN ' /Label for column 4
   TFORM5  = '32A     ' /Character string
   TTYPE5  = 'TDIM3   ' /Label for column 5
   TFORM6  = '1J      ' /Integer*4 (long integer)
   TTYPE6  = '2CRPX3  ' /Label for column 6
   TFORM7  = '1J      ' /Integer*4 (long integer)
   TTYPE7  = '2CDLT3  ' /Label for column 7
   TFORM8  = '1E      ' /Real*4 (floating point)
   TTYPE8  = '2CRVL3  ' /Label for column 8
   TFORM9  = '1J      ' /Integer*4 (long integer)
   TTYPE9  = '3CRPX3  ' /Label for column 9
   TFORM10 = '1J      ' /Integer*4 (long integer)
   TTYPE10 = '3CDLT3  ' /Label for column 10
   TFORM11 = '1E      ' /Real*4 (floating point)
   TTYPE11 = '3CRVL3  ' /Label for column 11
[...]

This binary table structure specifies that column 3 contains a set of
images stored in the heap, with the dimensions of each image given by
the corresponding row of column 5.  Note also that the coordinate
system information of the images are given by the other columns.

--John