Sample FITS WCS files


Mark Calabretta prepared these sample FITS images for each of the projections described in FITS-WCS Paper II using the same projection parameters as in the paper (where applicable).

Continuum data from the Parkes HIPASS survey (HI radio line) were used with gridding software based on WCSLIB. The particular field chosen contains the southern radio calibration source 1934-638.

Similar image parameters were used for each map; each is 192 x 192 pixels in size with pixel spacing (CDELTi) of 4 arcmin in each direction at the reference point which is at the south celestial pole. The reference pixel (CRPIXj ) was adjusted independently so that each image is centered with pixel coordinate (97,97) at equatorial (J2000) coordinates (18:59:51,-66:15:57), coincident with a 1.5Jy point source.

Because the images are offset some 25° from the reference point, non-linear distortions are clearly evident. An image based on the NCP projection is also included, although because the reference point is at the south celestial pole it is identical to the SIN projection.

The files are offered mainly as test material for software that deals with FITS WCS and may be obtained individually via the links below, or en masse as a 2.4MB compressed tar file.

If you have a FITS image browser registered with your web browser, it should display the images as you click on them.

Zenithal (azimuthal) projections
AZP Zenithal perspective
SZP Slant zenithal perspective
TAN Gnomonic
STG Stereographic
SIN Generalized orthographic
NCP North Celestial Pole (SIN special case)
ARC Zenithal equidistant
ZPN Zenithal polynomial
ZEA Zenithal equal area
AIR Airy's projection
Cylindrical projections
CYP Cylindrical perspective
CEA Cylindrical equal area
CAR Plate carrée
MER Mercator's projection
Pseudo-cylindrical projections
SFL Sanson-Flamsteed
PAR Parabolic projection
MOL Mollweide's projection
Conventional projections
AIT Aitov's projection
Conic projections
COP Conic perspective
COE Conic equal area
COD Conic equidistant
COO Conic orthomorphic
Polyconic projections
BON Bonne's projection
PCO Polyconic projection
Quad-cube projections
TSC Tangential spherical cube
CSC COBE quad-cube
QSC Quadrilateral spherical cube

By Dr. Mark R. Calabretta
Last modified 2005-02-18 by Doug Mink