EVN User Experiment Pipeline Feedback
Last updated: Mon Oct 11 14:31:21 CEST 2010
muehle@jive.nl
General Comments.
(
Brief data summary
and
scan listing
)
Pass 1: Doppler1 (vel = -24.5 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 source 'IRAS17230+01' was calibrated using the calibrator source '3C345'. The calibrator source '3C454.3' was 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.
stable bandpasses; a few very narrow spikes; 24 pages
plots of the uncalibrated amplitude and phase
against time
Comments.
except for Cm (very noisy) and the last scan, phases of the calibrator source can be followed even in the uncalibrated data; a check with a different reference antenna shows that the last scan is bad only at Ef: amplitude repeatedly drops to almost zero, accompagnied by phase jumps; 4 pages
Plots of the uncalibrated amplitude and phase
against frequency channel
Comments.
phases can be followed in the calibrator; stable amplitudes; Cm becoming noisier with time; 24 pages
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel
(not available)
Comments.
TSYS against time
Comments.
looks reasonable; 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 source 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); 2 pages
Fringe-fit rate solutions
Comments.
reference antenna: Ef; rates of the order of a few mHz; bigger for Cm and the last scan; 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 the last scan, phases of calibrator source close to zero; amplitudes look reasonable; Cm: noisy phases; after fringe fitting, essentially only the calibrator source remains; 4 pages
Calibrated amplitude and phase against frequency
channel
Comments.
phases of the calibrator close to zero; amplitudes look reasonable; 14 pages
Naturally weighted dirty map (not useful for bright sources)
produced before self-cal of:
3C345: 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)
.
Comments.
Phase corrections applied to a priori calibrated and
fringe-fitted data by self-calibration.
3C345
.
Comments.
refant: Ef; phase corrections in general within a couple of degrees (for the calibrator), larger for Cm; 2 pages
Amplitude corrections applied to a priori calibrated and
fringe-fitted data by self-calibration.
3C345:
pdf
, or
text file
, or
statistical summary
.
Comments.
Cm: high gain values (~2) with large variations; On: gains at about 0.7 (see also N09K3); 2 pages
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.
some outliers at start of scans; 2 pages
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
3C345
.
Comments.
closure phases clustered around zero; not surprisingly, plots including Cm are noisier than the others; 12 pages
Calibrated visibilities and the source model of:
3C345
.
Comments.
very good agreement between data and models; 4 pages
Calibrated visibilities against u,v distance for:
3C345:
pdf
, or
png
.
Comments.
u,v coverage for:
3C345:
pdf
, or
png
.
Comments.
Crude maps of sources:
3C345:
pdf
, or
FITS
.
Comments.