| wcsqpedit | xray.xproto | wcsqpedit |
wcsqpedit -- Edit the WCS parameters in a QPOE file.
wcsqpedit input_qpoe crval1 crval2 crpix1 crpix2 equinox radecsys
wcsqpedit allows users to modify any of 7 WCS keywords in the QPOE file. The available values are CRPIX1, CRPIX2, CRVAL1, CRVAL2, CROTA2, EQUINOX and RADECSYS. These values appear as simple keywords in a long imheader listing, but are inaccessible as header parameters using either hedit or qphedit. Users should exercise caution when making these modifications, since all knowledge of the original coordinate system is then lost.
The input qpoe file name to modify. User must have both read and write permission on the file. The file will be modified in place.
This is the value to be assigned to the axis 1 pixel size (in degrees). This is stored as a double precision real value, so be sure to express the value accurately. A value of -999.9 indicates the value currently in the QPOE file should NOT be changed.
This is the value to be assigned to the axis 2 pixel size (in degrees). This is stored as a double precision real value, so be sure to express the value accurately. A value of -999.9 indicates the value currently in the QPOE file should NOT be changed.
This is the value to be assigned to the axis 1 reference pixel. Normally this would be the Celestial RA. This is stored as a double precision real value, so be sure to express the value accurately. Only positive values are currently allowed. A value of -1 indicates the value currently in the QPOE file should NOT be changed.
This is the value corresponding to the axis 2 reference pixel. Normally this would be the Celestial Dec. This is stored as a double precision real value, so be sure to express the value accurately. Only values between -90.0 and +90.0 degrees are allowed. A value of -100, indicates the value currently in the QPOE file should NOT be changed.
This is the value corresponding to the image rotation relative to north. This is stored as a double precision real value, so be sure to express the value accurately. Only values between -360.0 and +360.0 degrees are allowed. A value of -1000.0, indicates the value currently in the QPOE file should NOT be changed.
This is the number of the reference pixel. It is the point in the physical data file to which the CRVAL1 value corresponds. It is often a value near the center of the axis, though this is not rEQUIRed. This is stored as a double precision real value, so be sure to express the value accurately. A value of -1 indicates that the value currently in the QPOE file should NOT be changed.
This is the number of the reference pixel. It is the point in the physical data file to which the CRVAL2 value corresponds. It is often a value near the center of the axis, though this is not required. This is stored as a double precision real value, so be sure to express the value accurately. A value of -1 indicates that the value currently in the QPOE file should NOT be changed.
This is the year of the EQUINOX. Often either 1950. or 2000. A value of -1 will cause the existing value in the file to be retained.
This is the name of the axis 1 coordinate system. Some possible values are RA---TAN, RA---SIN, LINEAR.
This is the name of the axis 1 coordinate system. Some possible values are DEC--TAN, DEC--SIN, LINEAR.
Label for the Coordinate system FK4 = B1950. FK5 = J2000. A NULL string will cause the current value in the file to be retained.
This is the length of the axis 1 coordinate system.
This is the length of the axis 2 coordinate system.
This is the display level. A value of 1 or greater will display the value currently in the file before prompting for a new value. A value of 2 or greater will display the value to be writtin to the file.
1. Change the WCS in the file from B1950 coordinates to J2000 coordinates. Note this changes the reference point only and does NOT reproject the data.
cl> xray
xr> ximages
xi> qpcopy xdata$snr.qp "" snr.qp ""
xi> xspatial
xs> skypix oformat="degrees"
input cooordinate system (xdata$snr.qp[bl=8]): xdata$snr.qp
output cooordinate system (xdata$snr.qp): J2000
input file list (STDIN):
Converting from xdata$snr.qp is
TANGENT 512. 513. -0.002222222 0.002222222 =
22:58:55.66 58:36:47.5 0.
EQUATORIAL B1950. in pixels
to EQUATORIAL J2000. in degrees
(Terminate interactive list with <cntl>-D)
512. 513.
345.2539 58.882
xp> wcsqpedit snr.qp
current CDELT1: -0.002222222000
cdelt1 (-999.9 no change) (-999.9): -0.0025
current CDELT2: 0.002222222000
cdelt2 (-999.9 no change) (-999.9):
current CRVAL1: 344.731900000000 (22:58:55.6560)
CRVAL1 (-1.0 no change) (-1.:360.) (-1.): 345.2539
current CRVAL2: 58.613190000000 (58:36:47.4840)
CRVAL2 (-100.0 no change) (-100.:90.) (-100.): 58.882
current CROTA2: 0.000000
CROTA2 (-1000.0 no change) (-1000.:360.) (-1000.):
current CRPIX1: 512.0000
CRPIX1 (-1.0 no change) (-1.):
current CRPIX2: 513.0000
CRPIX2 (-1.0 no change) (-1.):
current EQUINOX: 1950.0000
EQUINOX (-1.0 no change) (-1.):
current CTYPE1: RA---TAN
ctype1 (null - no change):
current CTYPE2: DEC--TAN
ctype2 (null - no change):
current RADECSYS: FK4
RADECSYS( e.g. FK4,FK5) (NULL - no change): FK5
current AXLEN1: 1024
X dimension (0 = no change) (0):
current AXLEN2: 1024
Y dimension (0 = no change) (0):
neglible
The documention for task skypix and the task wcsedit