EVN User Experiment Pipeline Feedback
Last updated: Thu Nov 26 19:28:59 CET 2009
muehle@jive.nl
General Comments.
(
Brief data summary
and
scan listing
)
Pass 1: LOC2SMG1
L band (18 cm) EVN experiment, observed on 05 June 2009. The data rate was 512 Mbps (8 x 8 MHz subbands, dual polarization, two-bit sampling). The data were correlated in three passes, with the phase center on the target sources 'LOC2SMG1', 'LOC2SMG2' and 'LOC2SMG3', respectively. The target sources 'LOC2SMG1', 'LOC2SMG2' and 'LOC2SMG3' were calibrated using the phase-reference source 'J1058+5628'. '4C39.25' served as fringe finder. 'J0958+4725' and 'J1740+5211' were also observed as calibrators. In the pipeline reduction of this pass, Ef served as reference antenna and as plot reference, i.e. the plots show baselines to Ef.
8 EVN stations were scheduled in this experiment: Ef, Jb, On, Mc, Nt, Tr, Ur, and Wb. There is low- to intermediate-level RFI at almost all stations, most severely at Mc and Tr. At Jodrell Bank, the Lovell telescope (labelled Jv here) had to be taken out of service due to a tyre crack at 11:23 UT. The MkII telescope (labelled Jb here) was used to complete the observations (from 12:34 UT). Wb observed in phased-array mode and only from ~11:30 until 23:30 UT because of its HA limits. One disk of the Ef disk pack crashed during the correlation of pass 2, leading to an increased noise level and data weights of w=0.25 after the failure.
The EVN reliability indicator (ERI) for this experiment was
ERI = 0.98 . ERI* = 0.98 .
(Ef=1, Jb=0.91, Mc=1, Nt=1, On=1, Tr=1, Ur=1, Wb=1)
Plots of the autocorrelations
Comments.
low- to intermediate-level RFI at almost all stations, most severly at Mc and Tr; Wb: wiggely, but stable bandpasses; 304 pages
plots of the uncalibrated amplitude and phase
against time
Comments.
phases of the calibrators and the phase-reference source can be followed even in the uncalibrated data; Jb: MkII telescope replaced the Lovell telescope from 12:34 UT; Wb: observed only from 11:30 UT to 23:30 UT due to HA limits; Jv: Lovell telescope out of service by 11:23 UT due to a tyre crack; 32 pages
Plots of the uncalibrated amplitude and phase
against frequency channel
Comments.
except for a few local glitches, phases can be followed in the calibrators and the phase-reference source; Jv out of service by 11:23 UT due to a tyre crack, replaced by Jb from 12:34 UT; 304 pages
The uncalibrated amplitude and phase of the crosshand
correlations against frequency channel
(not available)
Comments.
TSYS against time
Comments.
Wb: very noisy T_sys in IF1/R+L; Mc: Tsys in RCP channels significantly higher than in LCP channels; Nt: high T_sys in IF5/R; 15 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; 15 pages
Fringe-fit phase solutions
(including Parallactic
Angle correction).
Comments.
reference antenna: Ef, drift in phases reflects the parallactic angle correction; only a few glitches: Mc/IF6/R, Nt/IF2/R and Nt/IF8/R at ~11:00-11:30 UT; 15 pages
Fringe-fit delay solutions
Comments.
reference antenna: Ef; delays of the order of (tens of) nanoseconds; 15 pages
Fringe-fit rate solutions
Comments.
reference antenna: Ef; rates of the order of a few mHz; 15 pages
Telescope bandpasses
Comments.
reference antenna: Ef; in general, bandpasses look good, phases flat and close to zero; Wb, Tr, Nt: phases deviate significantly from zero at edges of the bandpasses; Jv completely flagged; 2 pages
Calibrated amplitude and phase against time
(a
priori amplitude calibration and fringe-fit solutions applied).
Comments.
phases of calibrators and phase reference source close to zero, amplitudes look reasonable; Jb: MkII telescope replaced the Lovell telescope from 12:34 UT; Wb: observed only from 11:30 UT to 23:30 UT due to HA limits; Jv completely flagged; 32 pages
Calibrated amplitude and phase against frequency
channel
Comments.
phases of the calibrators close to zero, amplitudes look reasonable; phases of the phase reference source close to zero, too, albeit with larger scatter; a few local glitches in individual scans; Jv completely flagged; 302 pages
Naturally weighted dirty map (not useful for bright sources)
produced before self-cal of:
4C39.25: pdf (not available)
, or
FITS (not available)
.
J1740+5211: pdf (not available)
, or
FITS (not available)
.
J0958+4725: pdf (not available)
, or
FITS (not available)
.
J1058+5628: pdf (not available)
, or
FITS (not available)
.
LOC2SMG1:
pdf
, or
FITS
.
Comments.
Uniformly weighted dirty map (not useful for bright sources)
produced before self-cal of:
4C39.25: pdf (not available)
, or
FITS (not available)
.
J1740+5211: pdf (not available)
, or
FITS (not available)
.
J0958+4725: pdf (not available)
, or
FITS (not available)
.
J1058+5628: pdf (not available)
, or
FITS (not available)
.
LOC2SMG1:
pdf
, or
FITS
.
Comments.
Phase corrections applied to a priori calibrated and
fringe-fitted data by self-calibration.
4C39.25
.
J1740+5211
.
J0958+4725
.
J1058+5628
.
LOC2SMG1 (not available)
.
Comments.
refant: Ef; phase corrections within a few degrees for the calibrators, a bit larger for the phase reference source; 12-13 pages per source
Amplitude corrections applied to a priori calibrated and
fringe-fitted data by self-calibration.
4C39.25:
pdf
, or
text file
, or
statistical summary
.
J1740+5211:
pdf
, or
text file
, or
statistical summary
.
J0958+4725:
pdf
, or
text file
, or
statistical summary
.
J1058+5628:
pdf
, or
text file
, or
statistical summary
.
LOC2SMG1: pdf (not available)
, or
text file (not available)
, or
statistical summary (not available)
.
Comments.
in general, gains look fine; Tr: more scatter than the other stations (because of RFI?), large variation in gains of the phase reference source in IF3-5/LCP until ~20:00 UT; 12-13 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.
nothing unexpected; a few spikes; 13 pages
Residual closure phase (visibility closure phase with model closure phase subtracted) for:
4C39.25
.
J1740+5211
.
J0958+4725
.
J1058+5628
.
LOC2SMG1 (not available)
.
Comments.
closure phases clustered around zero; a few outliers; 7-12 pages per source
Calibrated visibilities and the source model of:
4C39.25
.
J1740+5211
.
J0958+4725
.
J1058+5628
.
LOC2SMG1 (not available)
.
Comments.
in general, very good agreement between data and models; Wb: amplitude wiggles around model value in IF1/R+L (on calibrators only); 32 pages per source
Calibrated visibilities against u,v distance for:
4C39.25:
pdf
, or
png
.
J1740+5211:
pdf
, or
png
.
J0958+4725:
pdf
, or
png
.
J1058+5628:
pdf
, or
png
.
LOC2SMG1:
pdf
, or
png
.
Comments.
u,v coverage for:
4C39.25:
pdf
, or
png
.
J1740+5211:
pdf
, or
png
.
J0958+4725:
pdf
, or
png
.
J1058+5628:
pdf
, or
png
.
LOC2SMG1:
pdf
, or
png
.
Comments.
Crude maps of sources:
4C39.25:
pdf
, or
FITS
.
J1740+5211:
pdf
, or
FITS
.
J0958+4725:
pdf
, or
FITS
.
J1058+5628:
pdf
, or
FITS
.
LOC2SMG1:
pdf
, or
FITS
.
Comments.