DRLD updates for METIS_IFU_RSRF

[janusbrink]

The following changes should be finalised and updated in the DRLD for the RSRF recipe:

1. According to the METIS Calibration Plan, a set of WCU_OFF frames are a required input and stacked for use as a background image that is subtracted from the RSRF_RAW frames -> intermediate output IFU_RSRF_BACKGROUND.
2. The DRLD still mentions obtaining RSRF_RAW frames at two different blackbody temperatures. The Calibration Plan suggests that this is most likely not required.
3. The Calibration Plan mentions using the pinhole mask and scanning the pinholes along and across the IFU slits. If this is indeed the plan, the DRLD should be updated to reflect this as well as how the resulting output should be combined (or not).

[hugobuddel]

Thank you @janusbrink . Would you feel comfortable enough to try adding this information yourself?

We did not spent much time for PDR on the WCU_OFF in general or on the RSRF in particular, so thanks for noting this.

You could also make this issue directly in the DRLD repository: https://github.com/AstarVienna/METIS_DRLD

There are also some other issues about the RSRF there, e.g. AstarVienna/METIS_DRLD#134

[janusbrink]

Sure thing, will do @hugobuddel. OK if I make the changes on Overleaf?

[hugobuddel]

Go ahead, overleaf should synchronize with github automatically. I personally prefer to use github, because then I can make branches and such so I'm sure the document won't break

[hugobuddel]

You cannot run the consistency checks on overleaf though, you can do that locally with pytest. There are quite an (unnecessary) large amount of tables that need to be synchronized...