cable/fiber ID

[chad-earthscope]

Submitted by @EileenMartin

Right now it reads like there's just one cable-fiber ID for each portion of the fiber. Am I understanding that correctly?

As I'm working on an implementation of this in DASCore, I'm realizing it probably makes sense to keep a fiber ID and a cable ID for each portion of the light path.

Even though this may be redundant for some experiments, it's common enough to have a mix of straight stretches and loop-backs that I think it could help clarify acquisition setup for others after the fact.

A couple examples: This lets you leave a clear record when you start collecting data on a new fiber in the same cable. It also lets you have a clear indication of two fibers with a U connection at the end that sit in the same cable being differentiated from two fibers in two separate cables that are side-by-side or a cable deployed as a U. Or if you have a single mode DAS and a multimode DTS recording in the same cable (e.g. to do temp. corrections on your DAS data), and you use a similar metadata standard for DTS, then you can make it clear that they're in the same cable (and this means same thermal properties) versus side-by-side cables (potentially quite different thermal response).