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Focusliss scans for NIKA2 - Run1 (last update by B. Comis: 20/11/2015)
The following plots summarize the preliminary results of the systematic check that we are conducting on the NIKA2 focus scans. We have started by looking at the focusliss (Z, X and Y) scans, whose date and number are reported in the three plots of the bottom line.
From the focusliss scans, focus corrections are estimated by fitting the varying FWHM and fluxes with a curve (parabola), at both 1 and 2 mm. We then want to monitor the values of the FWHM (for both frequencies) at the optimal focus positions all along the campaign. But we also want to check what happens for Array 2 when we apply the focus corrections obtained from the minimization of the FWHM for Array 1. The plots in the upper line allow comparison between
* the FWHM of Array2 computed at the optimal focus position obtained from the best fit of the FWHM variations for A2
* the FWHM of Array2 computed at the optimal focus position obtained from the best fit of the FWHM variations for A1 (see legend in the plots).
This is done by interpolating the best fit curves of A2 at the optimal focus position estimated from the FWHM variations of A1. On the same plots, for both A1 and A2, we also show the minimum value of the five FWHM that are used for the fits. The dotted lines correspond to 12 (blue) and 18.5 (black) arcsec.
For the same scans, the bottom plots (in which the date and scan number are listed) show the difference between the focus correction based on the FWHM fit of A1 and A2.
We have also started a comparison between the optimal focus positions obtained with focusliss and track:
* Update with the missing scans (some focusliss scans are missing because we are experiencing some problems with the data back-up on one of the machine)
* Comparison with close focus track (ongoing)
* Comparison with old focusliss (ongoing)
* Look at FWHM vs elevation and pointing corrections