Resampling the Data

In the standard row-by-row option, the dispersion coefficients are kept in the table (coerbr.tbl). The rebinning to constant step in wavelength is accomplished, row by row, with the command REBIN/LONG.

If the 2-D option described above for the solution of the dispersion relation is followed (TWODOPT=YES), the polynomial coefficients in both directions are stored in the keywords KEYLONGD and COEFYD, respectively. This information is then used by the command RECTIFY/LONG to resample the image in the $(\lambda, s)$ space.

Data resampling  can be avoided by the command APPLY/DISPERSION which generates a table with the columns :WAVE and :FLUX, each row corresponding to the central wavelength and flux of a CCD detector pixel.