Discuss how to implement the future EBAS reader

[jgriesfeller]

This is to start a discussion about how to implement the future EBAS reader. The problem I want to solve is where to put the logic to connect pyaerocom variables to EBAS variables.
In addition, the amount of metadata that is allowd by pyaro is quite limited (although that has been extended recently). But at EBAS the metadata is file based and not station based, so there's an additional layer of complication.

Another thing is that in EBAS the measurement unit needs to be a part of the variable naming, because just using the "normal" matrix and component properties is not unique. Unfortunately the unit notation is not CF compliant in EBAS, so I'm not entirely sure how to encode that correctly.

Examples to be added at a later point...

[jgriesfeller]

Unit example:
EBAS: ug C/m3
CF compliant version: ug C m-3
cf_units.format(): 1e-09 m-3.kg.s.A (because it interprets C as Coulomb)

Pyaerocom actually sets the right unit, but I guess we don't want pyaerocom as a dependency of pyaro-readers. Shall I copy pyaerocom's Unit logic?

[jgriesfeller]

This has been done