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Daily Reports

2024 Feb. 20th, Tuesday

Ioannis, Kaiyi, Hervé, Philippe, and Ste B. arrived at the telescope.

Maintenance: the telescope and NIKA2 are healthy. The HWP has been tested and rotates correctly. All is ready for a great week

16:00-20:00; Angel, Stefano, Ioannis, Hervé, Kaiyi: Tuning after maintenance was very good (bad kids 13/2/16). It was done at high elevation of ~70 deg. Then we did pointing and focus on the quasar 0316+413. The beam size for several pointings remained ~ 17.7 x 18.5" at 2mm. The small ellipticity seemed to remain also after focus corrections. Atmospheric stability was ~ 2-5 Jy/beam for the 2mm data. Around 17:00 we started a training session of NIKA2 observations for Hervé and Kaiyi. Then started observations of project 150-23 and did also a skydip [scan 20240220s82]. After initial pointing, we loaded an OTF map on source "id307" but we had to stop the observations after only one scan was completed (around 19:30) because the wind velocity exceeded the limit (reached up to ~ 14 m/s). Tracking deterioration was also visible up to the point that we stopped.

Note that scan 20240220s82 was not processed and a "synchronization problem" message appeared on the PIIC ql monitor screen. The file size kept increasing for a long duration and I had to stop the imbfits creation process. After consulting with Stefano, we realized that this might have been caused because the telescope was slewing for a long time to the source position when a "pointing" command was issued. A "track" command should have been used instead to avoid this large imbfits file creation.

Input by Hervé: The shift was mostly dedicated to the observation of source id307 of the project 150-23. We also performed a 6 minutes skydip [20240220s82]. The beam was checked two times in a nearby target (source 0716+714), yielding a quite stable beam of ~ 17.5*19 arcsec. Observations started with good conditions (stability characterised by RMS of about +/- 1-2 Jy). Unfortunately, the shift closed at about 19:00 due to wind ~14 m.s-1. In the end, only the first scan (1/4) of the first of two rounds that were scheduled in the observation script was performed.

20:00-02:00; Philippe and Ioannis:

Wind... imagine strange noises... sigh.

2024 Feb. 21st, Wednesday

02:00-08:00; Stefano: after pointing and focus performed in nikaw-23, I switch on the good old "Telescope Chillin'" playlist to help me wake up and I start observing for 153-23. Very low wind (~3 m/s avg), very low tau (<0.1 on the 225 taumeter), very stable sky (<+/-0.5 Jy along the timeline of a pointing (first two subscans), i.e. scanning in Az).

• 2 repetitions of AR2623 (El~49-52 deg) before culmination
• pointing/focus check, rather important sidelobes (~10%) that influence the Gaussian fit of the main beam (MB) to be up to FWHM~17x19 arcsec at 2mm (note that it's a fit mislead by the sidelobes, i.e. not really MB only).
• 2x0.15 repetition of AR2747 at high elevation (El~74-77 deg) before culmination. See comments on Tapas.
• 2 repetitions of AR2623 after culmination
• pointing/focus check
• 2 repetitions of AR2747 after culmination
• pointing/focus check
• 1 last repetition of AR2747

Note the large pointing offsets (~11 ~7 arcsec) close to Az~180 deg (i.e. South) and El~55 deg.