- Form:COPW dest source [source2]
-
- dest
- is the destination spectrum to which a wavelength scale is to
be copied.
- source
- is the source spectrum from which the wavelength scale is
to be copied
- source2
- is a second source spectrum to be used for wavelength
interpolation
COPW will copy a wavelength calibration from one spectrum to another. This
is done to copy the wavelength scale computed with the WSCALE command from
the comparison spectrum to a program spectrum. The actual spectral data
are not changed by this command, only the wavelength calibration parameters
stored in the image header.
If a second source spectrum is given then the command assumes that you have
two comparison spectra which bracket the program spectrum in time, and it
will use the times of observations of the image headers of the three
spectra to do a linear interpolation of the wavelength parameters of the
comparisons to the time of the program spectrum. This procedure can
sometimes provide an improved wavelength calibration by correcting for the
effects of instrumental flexure.
Examples:
- COPW 3 2
- transfer the wavelength scale of spectrum 3 to
spectrum 2
- COPW 1 3 11
- transfer interpolate the wavelength scale
between spectra 3 and 11. Transfer this interpolated scale to
spectrum 1.