EVN Network Monitoring Experiment (NME) Pipeline Feedback


Pipeline feedback for experiment N08K4_3. If you have any comments on this experiment please email the address below.
A detailed description of the pipeline output is available.

Last updated: Thu Mar 12 13:30:22 CET 2009 muehle@jive.nl

General Comments. ( Brief data summary and scan listing )
This is part 3 of the network monitoring experiment N08K4.
K band (22 GHz + 24 GHz) network monitoring experiment (NME) observed on 3 November 2008. The data rate was 256 Mbps (8 x 8 MHz subbands, dual polarization, two-bit sampling). The experiment consists of three parts: The first part is the regular NME at 22GHz with a setup similar to the user experiment EB037E. The last 1.5 hours of the schedule were dedicated to tests of the new VLBA 24GHz continuum setup (part 2) and an NH3 spectral line setup (part 3).
In part 1, the target source 'J2254+1341' was calibrated using the phase-reference source '3C454.3'. 'J1751+09', '3C345', '2037+511', and '0202+319' were also observed as calibrators. '3C454.3' served as fringe finder. The maser sources 'RCas' and 'UHer' were observed to provide additional diagnostics to the stations. Part 2 consists of long scans on the calibrator '3C454.3'. In part 3, the known NH_3 maser source in W51 'W51MASER' (Zhang & Ho 1991, ApJ 373, L13) was calibrated using the phase-reference source 'J1930+1532'. '3C454.3' was also observed as a calibrator.
9 stations participated in part 1. 6 stations participated in parts 2 and 3. Cm transmitted signal in only two subbands, due to the limitations of its microwave link. In part 1, this is IF3 and IF4, in part 2 IF1 and IF2, and in part 3, IF1 and IF(?). Mh did not participate in the ftp fringe-tests because of network problems. There were no fringes to Ys, probably due to a faulty IF LO. An exchange of the LO seems to have fixed the problem for the following user experiment EB037E. No fringes were found to Sh, either, the likely cause being a fault in the elevation axle. Nt had no RCP, thus fed the LCP signal to all BBCs. The erraneous data in the RCP channels have been flagged in the postcorrelation process. Jb showed strong RFI-like symptoms in the fringe test, which may be due to an RF-related fault in the high-patch channel. The fraction of high bits in the Jb data was close to zero, so that Jb had to be correlated as a 1-bit station and has a much reduced sensitivity.

The EVN reliability indicator (ERI) for this experiment was ERI = 0.42 . ERI* = 0.42 . (CM=1, EF=1, JB=0.5, ON=1, MC=1, NT=0.5, SH=0, MH=1, YS=0)

Plots of the autocorrelations
Comments.
Cm: limited bandpass, signal in IF1 and ??? (not clear from the plots which other IF was transmitted); Jb: spiky bandpasses, possibly due to an RF-related fault in the high-patch channel; On: please check IF2/R; at times, (very) low level RFI at Ef, Mc, On; 54 pages

plots of the uncalibrated amplitude and phase against time
Comments.
Cm: limited bandpass, signal in IF1 and ???; amplitudes and phases match expectations; 24 pages

Plots of the uncalibrated amplitude and phase against frequency channel
Comments.
Cm: limited bandpass, signal in IF1 and ???; Jb: spiky bandpasses, noisy phases, possibly due to an RF-related fault in the high-patch channel; 54 pages

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

TSYS against time
Comments.
Cm, Jb: T_sys set to 1; On: unusually high T_sys in scan 50 (17:53-18:03), fine later = put in/adjusted attenuators? 5 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.
very good match to "TSYS against time"; 5 pages

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
refant = Ef; Cm: IF1 only, fast phases; Jb: no solutions in phase-referencing part; 4 pages

Fringe-fit delay solutions
Comments.
refant = Ef; delays of the order of (a few) tens of nanoseconds, except for Cm (120 nsec, 160 nsec); 4 pages

Fringe-fit rate solutions
Comments.
refant = Ef; rates of the order of mHz, a bit larger for Cm; 4 pages

Telescope bandpasses
Comments.
refant = Ef; Cm: phases at the edge of the bands deviate significantly from zero; Jb: noisy bandpass and phases (see comments above); 2 pages

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
refant = Ef; phases aligned, but still show significant deviations from zero; Cm: fast phase variations; On: amplitude of 3C454.3 decreases slightly during scan 51 (= source structure?); 16 pages

Calibrated amplitude and phase against frequency channel
Comments.
nothing unexpected detected; 45 pages

Naturally weighted dirty map (not useful for bright sources) produced before self-cal of:
W51MASER: pdf , or FITS .
J1930+1532: 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:
W51MASER: pdf , or FITS .
J1930+1532: 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.
W51MASER (not available) .
J1930+1532 .
3C454.3 .
Comments.
refant = Ef; few outliers; for the phase-reference source J1930+1532, phase corrections of up to 50 degrees; 3-4 pages per source

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
W51MASER: pdf (not available) , or text file (not available) , or statistical summary (not available) .
J1930+1532: pdf , or text file , or statistical summary .
3C454.3: pdf , or text file , or statistical summary .
Comments.
for the phase-reference source J1930+1532, gain solutions only for IF1/R+L; significant gain corrections for Jb; 1-4 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.
for the phase-referencing part, solutions only for IF1/R+L; Jb: gain in IF3/L only about half of gains in other IFs/pols; 4 pages

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
W51MASER (not available) .
J1930+1532 .
3C454.3 .
Comments.
some (minor) residuals for 3C454.3; larger residuals for J1930+1532; 1-2 pages per source

Calibrated visibilities and the source model of:
W51MASER (not available) .
J1930+1532 .
3C454.3 .
Comments.
for the phase-referencing part, solutions only for IF1/R+L; Cm: fast phase fluctuations; some amplitude deviations in individual IFs in combination with poor phase alignment for Cm and Mc; 4-16 pages per source

Calibrated visibilities against u,v distance for:
W51MASER: pdf , or png .
J1930+1532: pdf , or png .
3C454.3: pdf , or png .
Comments.

u,v coverage for:
W51MASER: pdf , or png .
J1930+1532: pdf , or png .
3C454.3: pdf , or png .
Comments.

Crude maps of sources:
W51MASER: pdf , or FITS .
J1930+1532: pdf , or FITS .
3C454.3: pdf , or FITS .
Comments.