o_ucd discussion

[Bonnarel]

Current text (September 28th) reads :

In the current UCD vocabulary (UCD1+ controlled vocabulary - Updated List of Terms Version 1.5) there appear to be no primary words suitable to describe raw SD data. o_ucd=phot.flux.density does not seem appropriate, since the single dish measured quantity is expressed in raw counts coming from the digitisation of a voltage signal generated in the receiver chain by the incoming electromagnetic field. Further discussion on o_ucd is ongoing within the Semantics WG.

I wonder if we should not say a word of calibrated data. o_ucd = phot.flux.density is valid in that case. Hopefully the new o_ucd term should be introduced before this extension text becomes a PR. The text above cannot stay "as is" in the specification

[BaptisteCecconi]

This has been discussed by the UCD group earlier today, and the proposal is to introduce a new UCD for voltage:

UCD = phys.voltage
Definition = Electric potential difference over a distance or measured by an instrument.

In the case proposed in the text, the example would have the UCD phys.voltage;instr.det;stat.uncalib