Back to the NIKA run 9

Day to day observation logbook

Nika 2014-10-07 sheet1

9 hours observed / 9 hours scheduled

Nika 2014-10-08 sheet2

9 hours observed / 9 hours scheduled

Nika 2014-10-09 sheet3

5 hours observed / 9 hours scheduled

Nika 2014-10-10 sheet4

9 hours observed / 9 hours scheduled

No observations on Sat-Sun night. 12th

0 hours observed / 8 hours scheduled

Nika 2014-10-13 sheet5

8 hours observed / 9 hours scheduled

No observations on Mon-Tue night. 14th

0 hours observed / 8 hours scheduled

see also TAPAS login with the project account specified on the log sheet (some nikas-14, some t21).

Quick summary of observations per day

Tuesday 7th

The beginning was a bit tough because Elvin considered we were GISMO where as all initializations were correct from the control room point of view. Juan Macias managed to twist our code to circumvent this and we could start observing. It took us then some time to tune the dectectors and retest the Real time analysis sequences. At some point, when we stopped the HWP, we lost the resonances at 1mm. In the last couple of hours, we installed the prism to have a first go with this kind of data.

Wednesday 8th

It was one of these nights... At the beginning, we were not seeing anything because M4 was not fixed properly. Then we had a hard time debug the our pointing code. In addition, the weather was not very nice, high opacity and rising, wind... making focus track also hard to get. We eventually tried our otf geometry on Uranus (not up in the sky at the beginning of the session) and found a very strong systematic effect while the HWP was rotating. Then we alternated between problems with the sky, the wind, extra noise with the HWP. We put and removed the polarizer, put and removed the prism to see how much it blocked this systematic and reflect/absorb the signal. By a quicklook at the measured Uranus flux and previous knowledge by Andrea, Alain and Samuel, we confirm that the prism reflects about 25% each face and absorbs about 25% too (=> ~40% global transmission). In the end, the MPPSync crashed so the HWP coult not be rotated any more.

Thursday 9th

We've worked on fixing the MPPSync, and we start our observing session, Alain is in the cabin trying to replug and relaunch it. It's been fixed but we've had problems with the resonances and the tuning all night, and bad weather. Lots of tests were performed on the instrument but few observations are available in the end.

Friday 10th

The tuning and acquisition worked fine again so we could carry out polarization observations during most of the night. However, there are a lot of gaps in the data (most likely due to missing antenna info, maybe because the acquisition is too resource-consuming) that prevented us from analyzing the data in live. We solved the issue we had with pointing offsets not being correctly interpreted in the pipeline reduction: this was due to Nasmyth offsets not being properly implemented.
- The wind prevented us from observing some sources that were located in directions were the wind would affect the antenna motors.
- The opacity was not great (between 0.5 and 0.7) but we could still do some bright sources.
Polarized sources observed:
- we tried to follow as much as possible BLLAC (about 6-8 maps taken with the HWP rotating, at elevations ranging from 70 to 25 degrees).
- NGC7538 3x3' maps obtained: 11 coverages with HWP rotating, 2 coverages without HWP rotating for comparison. - Cas A tentative map focusing on the brightest millimeter emission west of Cas A (23:23:15 +58:48:42.8). 4 coverages of a map that should cover 2x2' around this point.

Saturday-Sunday 12th night

Wind speed higher than 35m/s all afternoon and night, then snow... No observation.

Sunday-Monday 13th night

The weather improved significantly just when the observing session started. WFocus on getting polarized data, Andrea then Alain rotating the plate by hand in the cabin.

Monday-Tuesday 14th night

Bad weather.

D2DLogNika9 (last edited 2014-10-16 08:01:14 by NikaBolometer)