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Once you are satisfied with your line IDs, it is time to move on to for the wavelength solution. To launch the fit program, put the cursor or the graphics area and type capital 'F'. This launches the interactive 1D fitting GUI, shown below:
Wavelength FIT Sub-GUI
ffThe screen below shows an example of a first-pass wavelength fit, with pixel number on the x-axis and wavelength in y. Note that the fitting function is highly non-linear. This is a consequence of the wavelength dependent dispersion of the prisms, which is much stronger at the blue end of the spectrum.
