Address label design so that it interacts with Spectral LDD

[matthewtiscareno]

See the conversation at https://github.com/NASA-PDS/PDS4-CCB/issues/42

[matthewtiscareno]

We discussed this in our PDS4 group meeting today. @mit3ch suggested that, instead of using the Spectral LDD, we add a class to the Rings LDD that allows for a simple Wavelength Range to be defined. The Spectral LDD does not currently offer that functionality. Furthermore, although eventually we should cherish the goal of unifying different streams of usage for complete interoperability, what we need to do now is enable our current projects and look for that unification at a later time. I am good with this approach.

So, @markshowalter, stand by on this item. We will update the Rings LDD in the next few weeks.

[markshowalter]

(Pasted from my direct response on Slack). We have not yet attempted to generate geometric metadata for the HST products---that's the info that we would generally expect to be part of the RMS dictionary inside the label, but it'll have to be a future enhancement. For now, I agree that it would be good to include the wavelength ranges alone. For the purposes of the pipeline, we just need to create a lookup table mapping instrument, filter(s), and operating modes to wavelength range. However, populating this table is not at all trivial. For simple filters, we have the tools (rms-solar plus rms-tabulation) to multiply the solar spectrum by the filter bandpasses and then we can devise a definition of "min" and "max" that describes, say, 90% of the wavelength response. It'll take some reading of the documentation to figure out the bandpasses of all the grisms and the spectrometer instruments (STIS and COS).

[matthewtiscareno]

I had a conversation with Anne at the SDRW meeting last week at Caltech. She agrees that the HST spectral products that we are archiving are in such a raw state that they do not need to interact with the Spectral LDD.