Images processed by CCDPACK are resampled in one of two ways, depending on the value of the USEWCS parameter.
If USEWCS is TRUE then they are resampled from their Pixel coordinates into their Current attached coordinate system (this is the default). Since the resampling means that a 1 x 1 square in the Current coordinates will represent one pixel in the output image, the Current coordinate system must be of an appropriate size (so for instance resampling into SKY coordinates is not suitable because they have units of radians). The Current coordinate system will typically have been added by the CCDPACK REGISTER or WCSREG applications, and be labelled 'CCD_REG' or 'CCD_WCSREG' accordingly - if it has another label (domain) a warning will be issued but resampling will proceed. A copy of the original PIXEL coordinate system will be retained in the WCS component of the new image under the name CCD_OLDPIXEL; this can be useful for transforming positions back into the pre-transformation coordinate system.
If USEWCS is set to FALSE, then the resampling will take place according to the TRANSFORM structure stored in the .MORE.CCDPACK extension of the file. This option exists chiefly for compatibility with older versions of CCDPACK.
If the logging system has been initialised using CCDSETUP then the value specified there will be used. Otherwise, the default is "CCDPACK.LOG". [CCDPACK.LOG]
INsignifies that all the images in the current directory should be used and the output images should have the same names. Other types of modification can also be used, such as,
OUT -TRNwhich means call the output images the same as the input images but add -TRN to the end of the names. Replacement of a specified string with another in the output file names can also be used:
OUT RAWRESthis replaces the string RAW with RES in any of the output names.
Certain parameters (LOGTO and LOGFILE) have global values. These global values will always take precedence, except when an assignment is made on the command line. Global values may be set and reset using the CCDSETUP and CCDCLEAR commands.