EVN User Experiment Pipeline Feedback
Last updated: Mon Oct 11 14:31:28 CEST 2010
muehle@jive.nl
General Comments.
(
Brief data summary
and
scan listing
)
Pass 2: Doppler2 (vel = +60.1 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 'IRAS18525+02' and 'IRAS19083+08' 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: channels 1-660 flagged (no data transmitted through microwave link); in general, bandpasses stable; a few very narrow spikes; 46 pages
plots of the uncalibrated amplitude and phase
against time
Comments.
except for Cm, 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.
Cm: phases become noisier with time; phases can be followed in the calibrator sources, except for Cm after ~14:20 UT; 46 pages
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel
(not available)
Comments.
TSYS against time
Comments.
switch of calibrator sources clearly detectable at many stations (~15:50 UT); 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: only few and strongly variable solutions; almost 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; a few outliers, some of them huge; 2 pages
Fringe-fit rate solutions
Comments.
reference antenna: Ef; rates of the order of a couple of mHz, bigger for the few Cm solutions; a few outliers; 2 pages
Telescope bandpasses
Comments.
reference antenna: Ef; Cm: weird bandpass; phases flat and close to zero except for the edges of the bandpasses of Nt, Ys and Mh; 2 pages
Calibrated amplitude and phase against time
(a
priori amplitude calibration and fringe-fit solutions applied).
Comments.
phases of the calibrator sources close to zero; amplitudes look reasonable; Cm: few data remain, noisy phases; after fringe fitting, almost only the calibrator sources remain; 4 pages
Calibrated amplitude and phase against frequency
channel
Comments.
in general, phases of the calibrators close to zero (except for Cm); amplitudes look reasonable; 31 pages
Naturally weighted dirty map (not useful for bright sources)
produced before self-cal of:
3C345: pdf (not available)
, or
FITS (not available)
.
3C454.3: pdf (not available)
, or
FITS (not available)
.
Comments.
Uniformly weighted dirty map (not useful for bright sources)
produced before self-cal of:
3C345: pdf (not available)
, or
FITS (not available)
.
3C454.3: pdf (not available)
, or
FITS (not available)
.
Comments.
Phase corrections applied to a priori calibrated and
fringe-fitted data by self-calibration.
3C345
.
3C454.3
.
Comments.
refant: Ef; phase corrections in general within a couple of degrees (for the calibrators), Cm: few data remain; a few outliers; 2 pages per source
Amplitude corrections applied to a priori calibrated and
fringe-fitted data by self-calibration.
3C345:
pdf
, or
text file
, or
statistical summary
.
3C454.3:
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: few data remain, high gain values (~2) with large variations; On: gains at about 0.75 (3C345) and 0.8 (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.
looks reasonable; Cm: few data remain; 2 pages
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
3C345
.
3C454.3
.
Comments.
closure phases close to zero with small scatter; a few outliers; Cm: few data remain; 12 pages per source
Calibrated visibilities and the source model of:
3C345
.
3C454.3
.
Comments.
very good agreement between data and models; Cm: noisy phases, few data remain; 4 pages per source
Calibrated visibilities against u,v distance for:
3C345:
pdf
, or
png
.
3C454.3:
pdf
, or
png
.
Comments.
u,v coverage for:
3C345:
pdf
, or
png
.
3C454.3:
pdf
, or
png
.
Comments.
Crude maps of sources:
3C345:
pdf
, or
FITS
.
3C454.3:
pdf
, or
FITS
.
Comments.