XTENSION= 'BINTABLE' / binary table extension BITPIX = 8 / 8-bit bytes NAXIS = 2 / 2-dimensional binary table NAXIS1 = 3330 / width of table in bytes NAXIS2 = 68 / number of rows in table PCOUNT = 0 / size of special data area GCOUNT = 1 / one data group (required keyword) TFIELDS = 33 / number of fields in each row COMMENT wcsbth() ignores all of the above keywords except for TFIELDS which it COMMENT only considers to be advisory. In fact, TFIELDS here is incorrect COMMENT (deliberately) since WCS keywords are present below for column numbers COMMENT greater than 33. COMMENT ----------------------------------------------------------------------- COMMENT Use 'tofits' (supplied) to convert this file to FITS format via COMMENT sed '/^END$/q' bth.keyrec | tofits COMMENT ----------------------------------------------------------------------- COMMENT COMMENT WARNING WARNING WARNING COMMENT ------------------------- COMMENT This header has been developed for test purposes. It contains a mix COMMENT of WCS keywords whose presence within a single FITS header extends or COMMENT violates the FITS WCS standard. COMMENT COMMENT The main extension to the standard is the presence of image header COMMENT keywords in what is meant to be a binary table extension header. The COMMENT usage notes for wcsbth() in wcshdr.h explains how it interprets these COMMENT keywords. COMMENT COMMENT ----------------------------------------------------------------------- COMMENT ======================================================================= COMMENT COMMENT The primary image header keywords define a coordinate representation COMMENT using AIPS-convention WCS keywords. As it happens, no binary table COMMENT image array inherits these keywords and consequently they define an COMMENT "unattached" representation, one that is not associated with any COMMENT particular table column(s). Human intervention is required to form COMMENT such an association based on a priori knowledge. COMMENT COMMENT An old FITS WCS interpreter that only understood the AIPS convention COMMENT would most likely be confused by this header because NAXIS = 2 (above) COMMENT is fixed for a binary table. wcsbth() ignores NAXIS and deduces that COMMENT there are four coordinate axes by looking at the highest axis number COMMENT encoded in the WCS keywords themselves. COMMENT COMMENT An old FITS WCS interpreter also would not recognize the new WCSNAMEa COMMENT keyword, though its presence should not cause it any harm. It is set COMMENT here solely for identification purposes. COMMENT COMMENT This representation contains only standard image header keywords, but COMMENT their use in a binary table header is non-standard. COMMENT COMMENT ----------------------------------------------------------------------- COMMENT The following keyrecord is not part of the AIPS convention. WCSNAME = 'AIPS convention: TAN projection' / Name of this coordinate system CRPIX1 = 513.0 / Pixel coordinate of reference point CRPIX2 = 513.0 / Pixel coordinate of reference point CRPIX3 = 1025.0 / Pixel coordinate of reference point CRPIX4 = 1.0 / Pixel coordinate of reference point CDELT1 = -0.10 / x-scale CDELT2 = 0.10 / y-scale CROTA2 = 15.0 / Bulk image rotation CTYPE1 = 'RA---TAN' / Right ascension in a gnomonic projection CRVAL1 = 150.0 / Right ascension at the reference point CTYPE2 = 'DEC--TAN' / Declination in a gnomonic projection CRVAL2 = -30.0 / Declination at the reference point EPOCH = 2000.0 / Equinox of equatorial coordinates CDELT3 = 62.5e3 / Frequency scale CTYPE3 = 'FREQ ' / Frequency axis CRVAL3 = 1.3945e9 / Reference frequency VELREF = 258 / Barycentric radio velocity ALTRPIX = 0.0 / Alternate reference pixel (not handled) ALTRVAL = 0.0 / Alternate reference value (not handled) RESTFREQ= 1.42040575e9 / HI rest frequency CDELT4 = 1.0 / Stokes increment CTYPE4 = 'STOKES ' / Stokes convention axis (I, Q, U, V) CRVAL4 = 1.0 / Stokes I COMMENT ======================================================================= COMMENT COMMENT This coordinate representation utilizing a PCi_ja matrix expresses the COMMENT above AIPS convention header using standard WCS keywords. This set of COMMENT image header keywords with alternate representation 'I' is defined for COMMENT the purpose of inheritance (below) and so does not result in an COMMENT unattached representation as did the primary image header COMMENT representation above. COMMENT COMMENT This representation contains only standard image header keywords but COMMENT their use in a binary table header is non-standard. COMMENT COMMENT ----------------------------------------------------------------------- WCSAXESI= 4 / Number of coordinate axes CRPIX1I = 513 / Pixel coordinate of reference point CRPIX2I = 513 / Pixel coordinate of reference point CRPIX3I = 1025 / Pixel coordinate of reference point CRPIX4I = 1 / Pixel coordinate of reference point PC1_1I = 0.965925826289 / Coordinate transformation matrix element PC1_2I = 0.258819045103 / Coordinate transformation matrix element PC2_1I = -0.258819045103 / Coordinate transformation matrix element PC2_2I = 0.965925826289 / Coordinate transformation matrix element CDELT1I = -0.1 / [deg] Coordinate increment at reference point CDELT2I = 0.1 / [deg] Coordinate increment at reference point CDELT3I = 62500 / [Hz] Coordinate increment at reference point CDELT4I = 1 / Coordinate increment at reference point CUNIT1I = 'deg' / Units of coordinate increment and value CUNIT2I = 'deg' / Units of coordinate increment and value CUNIT3I = 'Hz' / Units of coordinate increment and value CTYPE1I = 'RA---TAN' / Right ascension, gnomonic projection CTYPE2I = 'DEC--TAN' / Declination, gnomonic projection CTYPE3I = 'FREQ' / Frequency (linear) CTYPE4I = 'STOKES' / Coordinate type code CRVAL1I = 150 / [deg] Coordinate value at reference point CRVAL2I = -30 / [deg] Coordinate value at reference point CRVAL3I = 1394500000 / [Hz] Coordinate value at reference point CRVAL4I = 1 / Coordinate value at reference point LONPOLEI= 180 / [deg] Native longitude of celestial pole LATPOLEI= -30 / [deg] Native latitude of celestial pole RESTFRQI= 1420405750 / [Hz] Line rest frequency RESTWAVI= 0 / [Hz] Line rest wavelength WCSNAMEI= 'AIPS convention: TAN projection' / Coordinate system title EQUINOXI= 2000 / [yr] Equinox of equatorial coordinates SPECSYSI= 'BARYCENT' / Reference frame of spectral coordinates COMMENT ======================================================================= COMMENT Binary table column 33 contains an image array, most of whose WCS COMMENT keywords would be inherited from the preceding image header keywords COMMENT with a = "I" provided that wcsbth() is invoked with an option that COMMENT allows it (i.e. by setting the WCSHDR_ALLIMG flag in its 'relax' COMMENT argument). COMMENT COMMENT Without full inheritance enabled, the presence of a single binary COMMENT table image array keyword, WCSN33I, would not be sufficient to cause COMMENT wcsbth() to create a wcsprm struct for this representation. However, COMMENT with inheritance enabled, WCSN33I is sufficient to trigger this COMMENT mechanism, in which case it overrides WCSNAMEI. COMMENT COMMENT Setting WCSHDR_AUXIMG alone only allows inheritance of the auxiliary COMMENT image header keywords. In this case it would not be sufficient to COMMENT cause wcsbth() to create a wcsprm struct for this representation COMMENT because there are no WCS keywords, either direct or inherited, that COMMENT allow the dimensionality of the coordinate system to be determined. COMMENT COMMENT The keyword is standard but such inheritance is non-standard. COMMENT ----------------------------------------------------------------------- WCSN33I = 'All WCS keywords inherited except for this one' / WCS title COMMENT ======================================================================= COMMENT Binary table column 44 is analogous to column 33 except with extra COMMENT binary table image array keywords that may override the image-header COMMENT equivalent if inheritance is enabled. COMMENT COMMENT wcsbth() would always create at least a 2D coordinate representation COMMENT for column 44, regardless of what other keywords were inherited. If COMMENT WCSHDR_ALLIMG was set, then a 4D representation would be constructed COMMENT from inherited keywords. WCSHDR_AUXIMG would not be sufficient for COMMENT this; however it would cause LONPOLEI and LATPOLEI to be inherited COMMENT (and four others) and these would affect the interpretation of the COMMENT coordinate system. COMMENT COMMENT The keywords are standard but such inheritance is non-standard. COMMENT ----------------------------------------------------------------------- WCSN44I = 'Most WCS keywords inherited' / WCS title 1CTY44I = 'RA---SIN' / Right ascension, orthographic projection 2CTY44I = 'DEC--SIN' / Declination, orthographic projection COMMENT ======================================================================= COMMENT Binary table keywords for the image array in column 77 with alternate COMMENT representation 'B'. COMMENT COMMENT This coordinate representation utilizing a PC (ijPCna) matrix COMMENT expresses the above gnomonic (TAN) projection as a slant zenithal COMMENT perspective projection (SZP) in order to test the reading of a number COMMENT of PVi_ma keywords. It also includes a linear time axis. COMMENT COMMENT This representation contains only standard keywords and usage. In COMMENT particular, it is is self-contained, i.e. no inheritance. COMMENT ----------------------------------------------------------------------- WCAX77B = 4 / Number of coordinate axes 1CRP77B = 513 / Pixel coordinate of reference point 2CRP77B = 513 / Pixel coordinate of reference point 3CRP77B = 1025 / Pixel coordinate of reference point 4CRP77B = 1 / Pixel coordinate of reference point 11PC77B = 0.866025404 / Coordinate transformation matrix element 12PC77B = 0.5 / Coordinate transformation matrix element 21PC77B = -0.5 / Coordinate transformation matrix element 22PC77B = 0.866025404 / Coordinate transformation matrix element 1CDE77B = -0.1 / [deg] Coordinate increment at reference point 2CDE77B = 0.1 / [deg] Coordinate increment at reference point 3CDE77B = -9.635265432e-06 / [m] Coordinate increment at reference point 4CDE77B = 1 / [s] Coordinate increment at reference point 1CUN77B = 'deg' / Units of coordinate increment and value 2CUN77B = 'deg' / Units of coordinate increment and value 3CUN77B = 'm' / Units of coordinate increment and value 4CUN77B = 's' / Units of coordinate increment and value 1CTY77B = 'RA---SZP' / Right ascension, slant zenithal perspective pro 2CTY77B = 'DEC--SZP' / Declination, slant zenithal perspective project 3CTY77B = 'WAVE-F2W' / Vacuum wavelength (linear in frequency) 4CTY77B = 'TIME' / Coordinate type code 1CRV77B = 150 / [deg] Coordinate value at reference point 2CRV77B = -30 / [deg] Coordinate value at reference point 3CRV77B = 0.214982042 / [m] Coordinate value at reference point 4CRV77B = -2000 / [s] Coordinate value at reference point 1V77_1B = 0 / [deg] Native longitude of the reference point 1V77_2B = 90 / [deg] Native latitude of the reference point 1V77_3B = 195 / [deg] alias for LONP77A (has precedence) 1V77_4B = -30 / [deg] alias for LATP77A (has precedence) 2V77_1B = 0 / SZP projection parameter 2V77_2B = 180 / SZP projection parameter 2V77_3B = 45 / SZP projection parameter 4S77_0B = 'UTC' / Coordinate transformation parameter LONP77B = 195 / [deg] Native longitude of celestial pole LATP77B = -30 / [deg] Native latitude of celestial pole RFRQ77B = 1420405750 / [Hz] Line rest frequency RWAV77B = 0.211061141 / [Hz] Line rest wavelength WCSN77B = 'St''d representation: SZP projection' / Coordinate system title 1CNA77B = 'Right ascension (J2000)' / Axis name for labelling purposes 2CNA77B = 'Declination (J2000)' / Axis name for labelling purposes 3CNA77B = 'Wavelength' / Axis name for labelling purposes 4CNA77B = 'Time offset' / Axis name for labelling purposes 3CRD77B = 1e-11 / [m] Random error in coordinate 3CSY77B = 1e-12 / [m] Systematic error in coordinate RADE77B = 'FK5' / Equatorial coordinate system EQUI77B = 2000 / [yr] Equinox of equatorial coordinates SPEC77B = 'BARYCENT' / Reference frame of spectral coordinates SOBS77B = 'TOPOCENT' / Reference frame of spectral observation VSYS77B = 1500 / [m/s] Velocity towards source SSRC77B = 'LSRK' / Reference frame of source redshift ZSOU77B = 0.0025 / Redshift of the source OBSGX77 = -4554231.9 / [m] ITRF observatory X-coordinate COMMENT OBSGEO-Y (below) should be inherited for OBSGY77. OBSGZ77 = -3454035.9 / [m] ITRF observatory Z-coordinate MJDOB77 = 35883.625 / [d] MJD of observation matching DOBS77 MJDA77 = 35883.7 / [d] MJD mid-observation matching DAVG77 DOBS77 = '1957-02-14T15:00:00' / ISO-8601 observation date matching MJDOB77 DAVG77 = '1957-02-14T16:48:00' / ISO-8601 mid-observation date matching MJDA77 COMMENT ======================================================================= COMMENT Pixel list keywords with axes in columns 8, 9 and 10 and alternate COMMENT representation 'P'. COMMENT COMMENT In the IRAF representation, if one CDi_ja (TCDn_ka) keyword is given COMMENT then the default is zero for any that are omitted. CDELTia (TCDLTna) COMMENT and CROTAn (TCROTna) keywords are included for informational purposes COMMENT only and otherwise are to be ignored. COMMENT COMMENT This representation uses the non-standard long form for some pixel COMMENT list keywords with non-blank alternate version specifier (these forms COMMENT are standard for a = ' ' only): COMMENT TCRPXna instead of TCRPna COMMENT TCDn_ka TCn_ka COMMENT TCDLTna TCDEna COMMENT TCUNIna TCUNna COMMENT TCTYPna TCTYna COMMENT TCRVLna TCRVna COMMENT TPVn_ma TVn_ma COMMENT TCNAMna TCNAna COMMENT TCRDEna TCRDna COMMENT TCSYEna TCSYna COMMENT Also, strictly speaking, alternate version codes are not defined for COMMENT TCROTn (e.g. TCROT9P below), and WCSNna should be TWCSna. However, COMMENT these are all considered to be natural extensions that all FITS WCS COMMENT interpreters should support. Apart from that, this representation COMMENT contains standard keywords and usage. In particular, it is is self- COMMENT contained, i.e. no inheritance. COMMENT ----------------------------------------------------------------------- TCRPX8P = 513 / Pixel coordinate of reference point TCRPX9P = 513 / Pixel coordinate of reference point TCRPX10P= 1025 / Pixel coordinate of reference point TCD8_8P = -0.08660254 / Coordinate transformation matrix element TCD8_9P = -0.05 / Coordinate transformation matrix element TCD9_8P = -0.05 / Coordinate transformation matrix element TCD9_9P = 0.08660254 / Coordinate transformation matrix element TC10_10P= -4.565153674e-5 / Coordinate transformation matrix element TCDLT8P = -0.10 / [deg] Coordinate increment at reference point TCDLT9P = 0.10 / [deg] Coordinate increment at reference point TCDLT10P= -4.565153674e-5 / Coordinate increment at reference point TCROT9P = 30.0 / [deg] Bulk image rotation TCUNI8P = 'deg' / Units of coordinate increment and value TCUNI9P = 'deg' / Units of coordinate increment and value TCTYP8P = 'RA---ZPN' / Right ascension, zenithal/azimuthal polynomial TCTYP9P = 'DEC--ZPN' / Declination, zenithal/azimuthal polynomial proj TCTYP10P= 'ZOPT-F2W' / Redshift (linear in frequency) TCRVL8P = 150 / [deg] Coordinate value at reference point TCRVL9P = -30 / [deg] Coordinate value at reference point TCRVL10P= 0.018577089 / Coordinate value at reference point TPV9_1P = 1 / ZPN projection parameter TPV9_3P = 0.333333333 / ZPN projection parameter TPV9_5P = 0.133333333 / ZPN projection parameter TPV9_7P = 0.053968254 / ZPN projection parameter TPV9_9P = 0.021869489 / ZPN projection parameter TPV9_11P= 0.008863236 / ZPN projection parameter TPV9_13P= 0.003592128 / ZPN projection parameter TPV9_15P= 0.001455834 / ZPN projection parameter TPV9_17P= 0.000590027 / ZPN projection parameter TPV9_19P= 0.000239129 / ZPN projection parameter LONP8P = 195 / [deg] Native longitude of celestial pole LATP8P = -30 / [deg] Native latitude of celestial pole RFRQ8P = 1420405750 / [Hz] Line rest frequency RWAV8P = 0.211061141 / [Hz] Line rest wavelength WCSN8P = 'IRAF representation: ZPN projection' / Coordinate system title TCNAM8P = 'Right ascension (J2000)' / Axis name for labelling purposes TCNAM9P = 'Declination (J2000)' / Axis name for labelling purposes TCNAM10P= 'Redshift' / Axis name for labelling purposes TCRDE10P= 5e-11 / Random error in coordinate TCSYE10P= 5e-12 / Systematic error in coordinate RADE8P = 'FK5' / Equatorial coordinate system EQUI8P = 2000 / [yr] Equinox of equatorial coordinates SPEC8P = 'BARYCENT' / Reference frame of spectral coordinates SOBS8P = 'TOPOCENT' / Reference frame of spectral observation VSYS8P = 1500 / [m/s] Velocity towards source SSRC8P = 'LSRK' / Reference frame of source redshift ZSOU8P = 0.00250000001174 / Redshift of the source COMMENT OBSGEO-X (below) should be inherited for OBSGX8. OBSGY8 = 2816758.3 / [m] ITRF observatory Y-coordinate OBSGZ8 = -3454035.9 / [m] ITRF observatory Z-coordinate MJDOB8 = 35883.625 / [d] MJD of observation matching DOBS8 MJDA8 = 35883.7 / [d] MJD mid-observation matching DAVG8 DOBS8 = '1957-02-14T15:00:00' / ISO-8601 observation date matching MJDOB8 DAVG8 = '1957-02-14T16:48:00' / ISO-8601 mid-observation date matching MJDA8 COMMENT ======================================================================= COMMENT COMMENT The following keywords have no alternates; they apply to each COMMENT coordinate representation, even that of the AIPS convention for COMMENT which, strictly, only the DATE-OBS keyword should be recognized. COMMENT COMMENT The keycomments for OBSGEO-Y and OBSGEO-Z have been omitted COMMENT deliberately for test purposes. COMMENT COMMENT ----------------------------------------------------------------------- OBSGEO-X= -4554231.9 / [m] ITRF observatory coordinates OBSGEO-Y= 2816758.3 / OBSGEO-Z= -3454035.9 MJD-OBS = 35883.625 / [d] MJD at start of observation (UTC) MJD-AVG = 35883.700 / [d] MJD mid-observation time (UTC) DATE-OBS= '1957-02-14T15:00:00'/ UTC date corresponding to MJD-OBS DATE-AVG= '1957-02-14T16:48:00'/ UTC date corresponding to MJD-AVG OBSGX99 = -4000000.0 / [m] ITRF observatory X-coordinate END * WCSLIB 4.3 - an implementation of the FITS WCS standard. * Copyright (C) 1995-2007, Mark Calabretta * * This file is part of WCSLIB. * * WCSLIB is free software: you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the * Free Software Foundation, either version 3 of the License, or (at your * option) any later version. * * WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for * more details. * * You should have received a copy of the GNU Lesser General Public License * along with WCSLIB. If not, see . * * Correspondence concerning WCSLIB may be directed to: * Internet email: mcalabre@atnf.csiro.au * Postal address: Dr. Mark Calabretta * Australia Telescope National Facility, CSIRO * PO Box 76 * Epping NSW 1710 * AUSTRALIA * * Author: Mark Calabretta, Australia Telescope National Facility * http://www.atnf.csiro.au/~mcalabre/index.html * $Id: bth.keyrec,v 4.3 2007/12/27 05:38:33 cal103 Exp $