Spectrum related classes

Note that there are a few closely related classes, with similar sounding names.

To keep everything straight, here is a list of some related classes:

• Spectrum - This is a full spectrum, which contains a SpectralRange and SpectralDomain.
• SpectralRange - This is the 'Y' axis of the spectrum, the value of the spectrum at a particular point. This may have a jacobian and/or uncertainty value include.
• SpectralDomain - This is the 'X' axis of the spectrum, the list of wavenumber/wavelength that we have values for.
• SpectralWindow - This give the window that we use for measured values that we use in a retrieval (i.e., the 'low resolution' spectrum). This is responsible for filtering out things like bad pixels, point that are beyond the edges of the microwindows.
• SpectrumSampling - This determines the high resolution points that we need for generating the low resolution we are fitting, i.e., the spectrum before it has been convolved with the Ils. This may skip points if we are using something like a NonuniformSpectrumSampling (which is then responsible for interpolating to the value needed by the Ils).
• SpectralBound - This gives the upper and lower bounds of a SpectralWindow. This is fairly coarse, it is used by some lower level classes that need to know roughly what wavenumber/wavelengths it will need to calculate for (e.g., LRadRt).
• ForwardModelSpectralGrid - This contains the various grids we use in the ForwardModel. This has the low resolution grid (i.e., what passed through our SpectralWindow), the high resolution grid that we run the RadiativeTransfer code on (possibly with nonuniform spacing), and the high resolution grid interpolated to supply what is needed by the Ils (which might be identical the noninterpolated grid if we aren't doing nonuniform spacing.