Possible design of an editable plaintext table containing WCS information

This design presumes that the detailed nature and interpretation of the root keywords is stored in some other data structure. De Clarke's FITS keyword database is such an example.

Here follows a draft schematic for the contents of the FITS header:

TableName: DEI_WCS

TableTypes: CCDPOS AMPPOS CTYPE CRPIX CRVAL CDELT PC CUNIT \
RADECSYS EQUINOX MJD_WCS DOMAIN PROJP

ROW: 1 1 { RA---TAN DEC--TAN } { 1. 1. } { 180. 45. } { 0.0001 0.0001 } \
{ 1. 0. 0. 1. } { deg deg } FK5 2000.0 { } FITS_PIX { }

ROW: 1 1 { RA---TAN DEC--TAN } { 1. 1. } { 180. 45. } { 0.0001 0.0001 } \
{ 1. 0. 0. 1. } { deg deg } GAPPT { } 50283.00 FITS_PIX { }

ROW: 1 1 { RA---SIN DEC--SIN } { 1. 1. } { 180. 45. } { 0.0001 0.0001 } \
{ 1. 0. 0. 1. } { deg deg } FK4 1950.0 { } FITS_PIX { }

ROW: 2 2 { GLON-TAN GLAT-TAN } { 1. 1. } { 180. 45. } { 0.0001 0.0001 } \
{ 0.86 0.5 -0.5 0.86 } { deg deg } { } { } { } FITS_PIX { }

ROW: 2 2 { ELON-TAN ELAT-TAN } { 1. 1. } { 180. 45. } { 0.0001 0.0001 } \
{ 0.86 0.5 -0.5 0.86 } { deg deg } { } {1997.} { } FITS_PIX { }

ROW: Guide 2 { DEIMASKX DEIMASKY } { 1. 1. } { .045 .31 } { 0.001 0.001 } \
{ 1. 0. 0. 1. } { m m } SLITMASK { } { } CCD_PIX { }

ROW: Guide 2 { DEWARFPX DEWARFPY } { 1. 1. } { .010 .008 } \
{ 0.000015 0.000015 } { 1. 0. 0. 1. } { m m } DEWAR_FP { } { } CCD_PIX { }

ROW: 8 2 { DEWARFPX DEWARFPY } { 1. 1. } { 180. 45. } { 0.00001 0.00001 } \
{ 1. 0. 0. 1. } { m m } DEWAR_FP { } { } CCD_PIX { }

ROW: { } { } { DEWARFPX DEWARFPY } { 0. 0. } { 180. 45. } { 8000. 8000. } \
{ 1. 0. 0. 1. } { m m } DEWAR_FP { } { } SLITMASK { }

ROW: { } { } { RA---TAN DEC--TAN } { 0. 0. } { 180. 45. } { 0.25 0.25 } \
{ 1. 0. 0. 1. } { deg deg } FK5 2000.0 { } SLITMASK { }

ROW: { } { } { DEIMASKX DEIMASKY } { 180. 45. } { 0. 0. } { 4. 4. } \
{ 1. 0. 0. 1. } { m m } FK5 2000.0 { } RA--DEC- { }
The semantics of the keywords/columns which are not derived from the draft WCS standard document are described in this data dictionary.

Take special note of the PROJPn keyword here. In all other cases the dimensionality of the inputs can be determined from the keyword database. This is not so for PROJPn.


Back to the WCS table idea page.
Back to the DEIMOS home page.
Steve Allen <sla@ucolick.org>
$Date: 1996/08/19 06:11:11 $