D2DLogNika7

Back to the NIKA run 7

Day to day observation logbook

Quick summary of observations per day

Mon, Jan 20

• First light. Check detector noise. Test main scripts to be used: track, cross, pointliss, focusp, focusliss, otfgeom, skydip_up, skydip_updown.

• Radio alignment by background minimization.
• No antenna data for the entire session.

Tue, Jan 21

• Investigation on the Nasmyth offsets: understand how the telescope Nasmyth reference coordinates are projected on the array.
• Investigation on the alignment: RADIO ALIGNMENT BY BACKGROUND MINIMIZATION DOESN'T WORK; using the laser alignment give stronger signals; the background minimization is probably due to vignetting of the pupil by the sky next to M2 (not the background behind M1!).

• Statistics on pointing corrections, pointing at a source for 1 hour. test script otf10x10.

• 3 beam maps (otfgeom script) on Uranus. 2 beam maps on 3C84.

Wed, Jan 22

• Iterations on focus scans to check focus variability.
• Additional tests on Nasmyth offsets.

• Use bad weather condition to test acquisition procedures and data with polarizer components: 1st modulator on, no half-wave plate, then with HWP immobile, then rotating. Try optimization of polarizer angle. Test scripts otf5x5, otf5x5_pol, otf5x5_half.

• Last test with Nasmyth offset, choose 'reference detector: 494 on the 2mm array (detector 5 on the 1mm array points ~2" away).

• Secondary calibrator: W3OH.
• 1 beam map on Uranus, 1 beam maps on 3C84, 1 beam map on W3OH.

Thu, Jan 23

• 3 beam maps on Uranus.
• Try pointing session... stopped half way through due to wind.

Fri, Jan 24

• Polarized observations: Uranus (including 3 beam maps), 3C454.3, 2013+270, MWC349, 3C84, 3C111. Test scripts pointliss_pol, otfgeom_pol.

• Try pointing session... stopped due to bad weather. 2 beam maps on 3C84.
• ~30 min on M82 (check for the supernova).
• ~20 min on GN20 (for noise analysis).

Sat, Jan 25

• 2 beam maps on Uranus

• Test that changing project ID in PaKo redirects the automatic fill of scan information into the appropriate table (accessible on line with the project login info) in the TAPAS and Pool data base. => one scan delay before the change is effective; to be corrected.

• Too windy for pointing session. Test various crosses speed in windy condition to investigate off line if an optimum can be determined. Default cross script was 120"/16s = 7.5"/s. No clear tendency from the quick look; last change in the script (new default): 120"/12s = 10"/s.
• 2 beam maps on 3C84, one slightly defocus to analyze beam shape and compare to simulation (need to understand why FWHM tends to be slightly bigger and elliptical than foreseen.

Sun, Jan 26

• Polarized observations: 3C454.3, 2013+270, CasAW, Crab. Test scripts otf3x3, otf4x2, otf4x4, otf10x2.

• Pointing session. 24 positions in the sky.

• One beam map on IRC10216 (14x13", but known flux 1.3Jy @ 1mm).

Mon, Jan 27

• 3 beam map on Uranus (3rd beam map with new pointing model).

• Too windy and not enough time for investigation of 3D focus with beam maps => 3D focus on central pixels (pointliss and cross); one position at the center (X=0,Y=0) and in each direction around the lateral focus plane for the optical on axis (Z) focus and one position on each side => 15 3D focus positions. Goal: check possible aberration, determine the optimal 3D focus, and see if we can understand the small aberration of the beams we had so far.

• Implementation of new pointing model (between 2nd and 3rd beam map on Uranus). But problem: after implementation pointings were off by > 15"; probably a sign convention error in the pointing model correction, to be understood and fixed for next run.

• Polarized observations: W3OH, 3C84.
• Back to continuum: faint source APM08279 for noise (sensitivity) analysis.