RIX PWb : Reduced 2D format

[astronomyk]

https://jira.eso.org/browse/MET-2079

It is a very good idea to store the reduced 2D detector images in such a way that they can be easily combined with other exposures later. However, it is not clear to me what data structure is really foreseen to do that. Saving the full wavelength solution plus slice location/distortion in a FITS header seems heavy. A table extension can carry more data efficiently, but also does not seem to be optimal for this case. Perhaps this should be described in Sect. 8.2.3.1 (p.241) on the IFU_SCI_REDUCED format.

@hugobuddel , pass this on if e.g. @sesquideus could tackle this

[hugobuddel]

I have no clue. We state in 6.6.3 metis_ifu_reduce

The recipe produces the following (intermediate) data products:
• Reduced 2D detector images. These are accompanied by additional information describing the geometry of the slice layout, target position and wavelength calibration to the ex tent that the exposure can be combined with other exposures into a single rectified spectral cube. This information can be stored in the FITS header or a table extension.
...

But then in section 8.2.3.1 IFU_SCI_REDUCED we don't explain how this is done at all.

I don't really understand how the IFU_SCI_REDUCED is supposed to be combined. 8.2.3.1 says that IFU_SCI_REDUCED (a 2D image) is input to metis_ifu_calibrate which produces a IFU_SCI_CUBE_CALIBRATED (a 3D cube). I believe this is an error.

I propose something like

The precise data structure for the auxiliary information for IFU_SCI_REDUCED (reduced 2D detector images) is not yet properly defined. We will define this data structure and describe it in 8.2.3.1 (IFU_SCI_REDUCED).

OK @sesquideus ?

[hugobuddel]

Answered with

The precise data structure for the auxiliary information for IFU_SCI_REDUCED (reduced 2D detector images) is not yet fully defined. We will define this data structure and describe it in 8.2.3.1 (IFU_SCI_REDUCED).

Still quite some work to actually do that

[sesquideus]

I'm fine with this. Sadly I have little idea about the data structures yet.