EVN User Experiment Pipeline Feedback

Last updated: Mon Oct 11 14:31:49 CEST 2010 muehle@jive.nl

General Comments. ( Brief data summary and scan listing )
Pass 3: Doppler3 (vel = -58.0 km/s)
K band spectral line EVN experiment, observed on 27 October 2009. The data rate was 64 Mbps (1 x 8 MHz subband, dual polarization, two-bit sampling). The data were postprocessed and pipelined in three passes, with doppler source velocities of -24.5 km/s, +60.1 km/s and -58.0 km/s, respectively. In this pass, the target sources 'IRAS19566+34' and 'IRAS20052+05' were calibrated using the calibrator sources '3C345' and '3C454.3'. '3C454.3' was also the fringe finder. In this pipeline reduction, Ef served as reference antenna and as plot reference, i.e. except for the autocorrelations, the plots show baselines to Ef.
8 EVN stations were scheduled in this experiment: Cm, Ef, Jb, Mc, Mh, Nt, On, and Ys. Mc reported a fault in the patch panel configuration until 19:00 UT, making scan #46 the first valid scan. The recorded data show an unusually low fraction of high bits in particular in the RCP channel, resulting in a reduced sensitivity, but fortunately not a complete loss of the data before 19:00 UT. The microwave link to Cm was unstable. At Mh, there were rain showers from 16:00 UT. More details about the observations and the data can be found in the letter to the P.I. which is also available from the archive (section "Standardplots").

The EVN reliability indicator (ERI) for this experiment was ERI = 1.0 . ERI* = 1.0 . (Cm=1, Ef=1, Jb=1, Mc=1, Mh=1, Nt=1, On=1, Ys=1)

Plots of the autocorrelations
Comments.
Cm: bandpass varies with time; Mc: bandpass changed slightly around ~19:00 UT (panel adjustment); other bandpasses stable; a few very narrow spikes; 46 pages

plots of the uncalibrated amplitude and phase against time
Comments.
except for Cm (very noisy), phases of the calibrator sources can be followed even in the uncalibrated data; a few outliers in amplitude at several stations; 4 pages

Plots of the uncalibrated amplitude and phase against frequency channel
Comments.
phases can be followed in the calibrator sources, except at times for Cm ; 46 pages

The uncalibrated amplitude and phase of the crosshand correlations against frequency channel (not available)
Comments.

TSYS against time
Comments.
Mc: jump in T_sys at ~19:00 UT (panel adjustment), high T_sys in RCP channel afterwards; 2 pages

Telescope sensitivities from the a priori TSYS and Gain curves (the square of this number gives the antenna noise (SEFD) in Jy - the smaller the better).
Comments.
curves match closely those of T_sys vs. time; 2 pages

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
reference antenna: Ef, drift in phases reflects the parallactic angle correction; Cm: strongly variable solutions; essentially only solutions for the calibrator sources found by the pipeline; 2 pages

Fringe-fit delay solutions
Comments.
reference antenna: Ef; delays of the order of a few tens of nanoseconds ( < 20 nsec) with very little scatter; 2 pages

Fringe-fit rate solutions
Comments.
reference antenna: Ef; rates of the order of a couple of mHz, bigger for Cm; a few outliers; 2 pages

Telescope bandpasses
Comments.
reference antenna: Ef; bandpasses look good; phases flat and close to zero except for the edges of the bandpasses of Cm, Nt, Ys and Mh; 2 pages

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
except for a few glitches (e.g. Ef at ~16:48 UT), phases of calibrator sources close to zero; amplitudes look reasonable; Cm: noisy phases; after fringe fitting, essentially only the calibrator sources remain; 4 pages

Calibrated amplitude and phase against frequency channel
Comments.
phases of the calibrators close to zero; amplitudes look reasonable; Mc: amplitudes changed slightly after ~19:00 UT (panel adjustment); 26 pages

Naturally weighted dirty map (not useful for bright sources) produced before self-cal of:
3C454.3: pdf (not available) , or FITS (not available) .
3C345: pdf (not available) , or FITS (not available) .
Comments.

Uniformly weighted dirty map (not useful for bright sources) produced before self-cal of:
3C454.3: pdf (not available) , or FITS (not available) .
3C345: pdf (not available) , or FITS (not available) .
Comments.

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
3C454.3 .
3C345 .
Comments.
refant: Ef; phase corrections in general within a couple of degrees (for the calibrators), larger for Cm; a few outliers; 2 pages per source

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
3C454.3: pdf , or text file , or statistical summary .
3C345: pdf , or text file , or statistical summary .
Comments.
gains in general closer to 1.0 at start of the experiment (3C345) than later on (3C454.3); Cm: for 3C454.3 high gain values (~3) with large variations; Mc: jump in gain at ~19:00 UT, in particular in the RCP channel; On: gains at about 0.7 (3C345) and 0.6 (3C454.3), respectively (see also N09K3); 2 pages per source

Telescope sensitivities (the total AMP gain applied during both a priori and self calibration; the square of this number gives the antenna noise (SEFD) in Jy).
Comments.
a few outliers, e.g. at ~16:48 UT (bad data in refant, not flagged); 2 pages

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
3C454.3 .
3C345 .
Comments.
closure phases clustered around zero; a few outliers; not surprisingly, plots including Cm tend to be noisier than the others; 12 pages per source

Calibrated visibilities and the source model of:
3C454.3 .
3C345 .
Comments.
very good agreement between data and models; Cm: noisy phases; 4 pages per source

Calibrated visibilities against u,v distance for:
3C454.3: pdf , or png .
3C345: pdf , or png .
Comments.

u,v coverage for:
3C454.3: pdf , or png .
3C345: pdf , or png .
Comments.

Crude maps of sources:
3C454.3: pdf , or FITS .
3C345: pdf , or FITS .
Comments.