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SB NOTES. Last update: 2025/07/18.

Notes for the next re-commissioning campaign(s)

Following the results of the July 12-13th, 2025 session (run 74), the discussion at the 2025/07/16 NIKA2 meeting, and the reduction of the run 74 beam maps, it turns out that we will need at least another re-commissioning session to take high-quality beam maps and be able to produce "final" DAFs/RPPs/Kidpars for the new Ar1 and Ar3.

Carsten said that few hours of NIKA2 recommissioning could be included in the next EMIR pool (August 19-26th). Therefore it is important to make so that NIKA2 will be cold during that week. Miguel will be the AoD. Similarly, there will be another EMIR pool in Spetember, but it has not been scheduled yet.

Here come some notes and suggestions about how to proceed with the next re-commissioning time.

Main Goals

• produce high-quality DAFs/RPPs and Kidpars
• produce new final NEFDs for total power
• produce new final NEFDs for polarimetry (probably and likely in Autumn).

Observations priorities

• the prioriy are high quality beam maps for all three arrays

• a small deep field centered on a moderately bright source (few hours, say at least 5). See a list of possible targets by Xavier at the bottom of this page.
• calib_1scans: we will need to have a good statistics and probably we will need to use those taken during the future science pools to reach a consensus on the new NEFDs
• focus sequences
• for the polarimetry NEFDs, we'll likely use science pools data

Comments and impressions by SB about the last re-commissioning session (run 74)

• We still do not have DAFs/Kidpars with the central KID as reference for all three arrays. With the June 3rd intervention, Box C was recovered, therefore we can use the Ar2 DAFs/Kidpars of run 68 (the SWEEP hasn't changed). On the other hand for the new Ar1 and Ar3 we do not have yet any DAFs/Kidpars with the central KID (in Box C - Ar2) as reference because run 72 had no Box C and the beam maps of run 73 were not good enough.
• Therefore the priority of run 74 were beam maps rather than calib_1scans
• The daily report of run 74 mentions a problem with the focus of Ar1 and Ar3. this was followed up also in an emails exchange yesterday. The problem here is that the DAFs of Ar1 and Ar3 are shifted wrt those of Ar2. We need to use the Ar2 centered on the the central KID, though, because we need to produce DAFs well cenetred also for Ar1 and Ar3. This shift makes so that the source in Ar1 and Ar3 is far from the center (it's only a software shift, not a real one), and falls out of the 30 arcsec circle that is used by the PIIIC QL to "mask" the source. Consequently the data reduction rejects the KIDs that see the source, because the timelines are "too noisy" (the source is not masked).
• the daily report also mentions that the old imbfits scripts did not work. SB looked for the data but he took some time to find them because he was looking for those produced by the old make-imbf scripts. The question is whether the new make-imbf data are now free from the "slow/fast/fused traces problem" that started in February. If yes, then PIIC can process the beam maps imbf produced in this way. If not, then it can't because times are not monotonic. Miguel reports that the problem was recently fixed by OHB, therefore there should be no problem. There are still a couple of such events per day, but nothing dramatic.
• SB will then process th ebeam maps in the next days
• Jean suggests that some fix could be implemented in PIIC, in case the remaining few events per day would affect some NIKA2 scans. SB says that we should understand first if it's worth it: in order to implement a patch, he needs to find where in PIIC to do it (which takes at least one month of study of the code), then few hours of coding, and finally few days of testing. He thinks that recovering a couple of scans per day, it is not worth to work more than one month on PIIC.

Current PIIC DAFs status

The run 74 beam maps have been processed with PIIC (see this page) and new DAFs RPPs have been produced for Ar1 and Ar3. These new run 74 DAFs are sub-optimal: Ar3 is missing a significant number of KIDs and both Ar1 and Ar3 were not optimally focused. Nevertheless, these DAFs RPPs have all three arrays aligned with the central reference KID (KID 363 of Ar2 - run 68 sweep -, in PIIC conventions, see run 72 daily reports and data reduction).

The DAFs used during the observations of run 73 and 74, are also still available. The advantage of these former DAFs is that Ar1 and Ar3 have all KIDs. The drawback is that the RPPs of Ar1 and Ar3 were produced during run 72 and therefore have an offset with respect to the RPPs of Ar2 (based on run 68).

I have installed the run 74 DAFs as default for PIIC at Pico Veleta. When setting up the PIIC environmental variables with gagpiic and starting PIIC, the environment variable $MOPSIC_DAFS points by default to /sw/gildas/mopsic/dafs.

The formed DAFs that have an offset of Ar1 and Ar3 with respect to Ar2, but include all Ar1 and Ar3 KIDs and have a better quality of the Ar1 and Ar3 geometry are instead stored in the directory /local/users/flexible/reduce/dafs_bck/dafs_local_tmp_run73_ar2_extended/.

Strategy for observations and for using the PIIC QL

Given what written above about the PIIC DAFs, by default PIIC will use the DAFS/RPPs that have holes (missing KIDs) but have all three arrays referenced to the central KID.

• During the observations, the QL will run and will produce maps using these DAFs.

• If the maps are satisfactory and if there are no problems with the QL execution, simply keep these DAFs.

On the other hand, if the maps are not OK, or if the QL encounter problems, you can switch to the former version:

• exit PIIC
• execute the command export MOPSIC_DAFS=/local/users/flexible/reduce/dafs_bck/dafs_local_tmp_run73_ar2_extended
• start PIIC again
• Important note: the path of this alternative DAFs is long. It might happen that the DAFs filenames+path become too long and PIIC will not find them. If so, then please copy them locally in the home directory and point the $MOPSIC_DAFS variable to them

Observing procedure, when using the default DAFS /sw/gildas/mopsic/dafs

This case is pretty standard, because the RPPS of the three arrays are aligned to the same central KID.

• as a start, the priority are high-quality beam maps. Possibly at least two per array.

  • @nkpoint b
  • set pointing XX YY (use the Ar2 offsets)
  • @focusOTF-Z zz
  • if the focus range covers also the optimal focus of Ar1 and Ar3, mark them down.
  • set focus ZZ !!! (use the Ar2 focus)
  • @nkpoint b
  • set pointing XX YY !!! (use the Ar2 offsets)
  • @beam map 99 scans !!! (this is going to be the Ar2 beam map)
  • @focusOTF-Z zz !!! (start from the Ar1 focus optimal position marked down before)
  • set focus ZZ !!! (use the Ar1 focus)
  • @nkpoint b
  • set pointing XX YY !!! (use the Ar2 offsets)
  • @beam map 99 scans !!! (this is going to be the Ar1 beam map)
  • @focusOTF-Z zz !!! (start from the Ar3 focus optimal position marked down before)
  • set focus ZZ !!! (use the Ar3 focus)
  • @nkpoint b
  • set pointing XX YY !!! (use the Ar2 offsets)
  • @beam map 99 scans !!! (this is going to be the Ar3 beam map)
• then proceed with the other observations. The order here is relatively arbitrary. We wish to have a small deep field, if possible. The different kind of scans can be simply alternated.
  • a deep field (5 hours on source). See a list of possible targets by Xavier at the bottom of this page.
  • focus sequences for Ar2, Ar1 and Ar3
  • calib_1scan on primary and secondary calibrators

Observing procedure, when using the dafs_local_tmp_run73_ar2_extended/ DAFs are used

(by SB, double checked by Lea)

These DAFs are - so to say - "hybrid": Ar2 DAFs referred to the central KID (i.e. run 68 DAFs); Ar1 and Ar3 DAFs shifted (i.e. run 72 DAFs). The observing procedure to obtain a well focused beam map for all three arrays requires a bit more work:

• as a start, the priority are high-quality beam maps. Possibly at least two per array.

  • @nkpoint b
  • set pointing XX YY !!! (use the Ar2 offsets)
  • @focusOTF-Z zz
  • set focus ZZ !!! (use the Ar2 focus)
  • @nkpoint b
  • set pointing XX YY !!! (use the Ar2 offsets)
  • @beam map 99 scans !!! (this is going to be the Ar2 beam map)
  • @nkpoint b
  • set pointing XX YY !!! (use the Ar1 offsets)
  • @focusOTF-Z zz
  • set focus ZZ !!! (use the Ar1 focus)
  • @nkpoint b

  • set pointing XX YY !!! (use the Ar2 offsets)

  • @beam map 99 scans !!! (this is going to be the Ar1 beam map)
  • @nkpoint b
  • set pointing XX YY !!! (use the Ar3 offsets)
  • @focusOTF-Z zz
  • set focus ZZ !!! (use the Ar3 focus)
  • @nkpoint b

  • set pointing XX YY !!! (use the Ar2 offsets)

  • @beam map 99 scans !!! (this is going to be the Ar3 beam map)
• then proceed with the other observations. The order here is relatively arbitrary. We wish to have a small deep field, if possible. The different kind of scans can be simply alternated.
  • a deep field (5 hours on source). See a list of possible targets by Xavier at the bottom of this page.
  • focus sequences for Ar2, Ar1 and Ar3
  • calib_1scan on primary and secondary calibrators

List of possible deep field target, by Xavier

2025/07/18 by Xavier: suggested list of potential targets for the deep field. Simply pick one of them and integrate for at least 5 hours.