Hi Kazi -- The full correlation and FITS preparation for ER026D has finished, and I've just finished reviewing the results and preparing various plots for you to look at. The correlation had three passes, using: 9 stations (JbWbEfMcTrOnYsShVm) GEODETIC: 8 8MHz IFs (Upper/Lower sidebands; DC edges = 6620.99, 6640.99, 6664.99, 6690.99) 2 polarizations per IF (parallel hands) 32 frequency points per IF/pol 2s integration time CONTINUUM: 8 8MHz IFs (Upper/Lower sidebands; DC edges = 6640.13, 6656.13, 6672.13, 6688.13) 2 polarization per IF (parallel hands) 32 frequency points per IF/pol 1s integration time LINE (2 passes, one perpol): 1 8MHz IFs (Lower sideband; 6664.13-6672.13 = AIPS IF5 from continuum) 1 polarization per IF (parallel hands) 1024 frequency points per IF/pol 1s integration time You can download the FITS files directly from the Data Archive as described below (you can arrange a password through me), or we can make DATs/DVDs and mail them to you. Each individual FITS file is ~1.8GB, and the different passes contain: continuum: 4 files 7.1 GB er026d_1_1.IDI lineR: 8 files 14.2 GB er026d_3_1.IDI lineL: 8 files 14.2 GB er026d_4_1.IDI geodetic: 1 file 0.2 GB er026d_5_1.IDI1 The er026d.README file on the archive also contains this information. The numbering of the line & geodetic passes remains the same as in the previous epochs, even though this one did not call for separate passes for the two polarizations for continuum. Disks can be eligible for release two weeks after distribution (because it took such a long time to get the Vm data, from a practical matter, they'll be recycled for Oct/Nov'12). If you have any questions, contact us at jops@jive.nl EVN and Global VLBI Observations correlated at the EVN MkIV Data Processor at JIVE are now automatically calibrated via a pipeline process. You will receive email notification when the pipeline is complete. In particular, the a priori amplitude calibration table (and the associated, final ANTAB file), plus various other tables and plots will be available to download from the Pipeline page on the EVN archive. (Note that the unprocessed station- generated *.antabfs files under the Station Logfiles page of the archive are not directly usable.) A description of the pipelining process can be found at: www.evlbi.org/pipeline/user_expts.html The EVN data archive at JIVE is now a central location for obtaining the information you need in reviewing your project. You can find network feedback from the stations, standard plots from the correlation review done here prior to distribution, pipeline results, and the FITS files themselves. Contact your support scientist to arrange for a password with which you can download your FITS file(s) from the archive directly. See the EVN Users' Guide in www.evlbi.org for a link to the EVN Archive policy -- in short, data from sources you identified as target/private in pre-correlation e-mail will not be made public, nor will pipeline images be made from them, for one year from distribution. The archive can be accessed via: www.jive.nl/select-experiment (or via the menu items of the main jive page www.jive.nl). Once in this portal to the EVN data archive, you can click on your experiment in the pull-down menu in the "Select Experiment" window; then click on the link "Show Experiment" that will appear immediately below this. You will then see a new window for your experiment, from which you can select from the various sorts of data available from the menu row along the top: *) Station Feedback = information provided by the stations' VLBI friends about the conduct of the experiment *) Station Logfiles = sched-based files you uploaded to VLBEER, observing log-files from the stations, other unprocessed station-generated files. *) Standard plots = the plots described below in a variety of formats, a copy of this cover letter *) Pipeline = pipeline plots; the ANTAB & UVFLG files used in pipelining *) Fitsfiles = FITS files, plus an associated README in case there are multiple correlator passes each with its own set of FITS files. Papers that result from your EVN observations should carry the standard EVN acknowledgment: The European VLBI Network is a joint facility of European, Chinese, South African and other radio astronomy institutes funded by their national research councils. -----------------o----------------- General comments: Ef - Lost a couple of 2-3 minute periods due to elevation-control failure. The noise diode failed from ~1700-2100, seen from the gap in the pipeline TSYS and straight-line portion in the pipeline GAIN plots. The station said they'd try to introduce some reasonable numbers in their antabfs, which apparently hasn't happened yet. We can pursue this, and if necessary re-pipeline from the antab step. Jb - No fringes in IF3-4/LL in the geodetic block only (same behavior as in the EB039 & EB032/GB063 series). Mc - Time-dependent rippling in the passband, hinted at in the AUTO plots in the line passes. It's worse in the second half of the experiment, occasionally affecting the shape of the passband (e.g., distortions at the 2-3rd harmonic scale). The response of the maser emission in the Mc auto-correlation is still almost always discernable (by eye). This behavior also applied in ER026C (not mentioned in that cover letter). Tr - IF5-6/LCP (BBC06) was dead in all modes. Unfortunately, the LSB of this BBC held the line, so no useful Tr data for lineL. Wb - Observed as a single dish (only 1 5cm receiver). With new digital back end, takes ~3min to change frequencies between the geodetic and the continuum/line modes (& back). Vm - only LCP signal. -----------------o----------------- PLOTS See the associated plotdescription.txt for an explanation of the unusually complicated plots made during the course of reviewing the data. All plots discussed here were made while the data were still in aips++ Measurement Sets prior to conversion to FITS files. The station/IF numbering is 0-based in the aips++ plots, but 1-based in the FITS data (1-based numbering used below). Specific points in regard to the various plots are below. (a) WEIGHT plots Before making the FITS files, I flagged weights at 0.6 (integrations below this are in the FITS files, but with negative weights). Also flagged Tr-* IF5-6/LL, but after making the AUTO & CROSS plots to show that the IFs were dead. (b) AUTOCORRELATION SPECTRA [*auto*] plots The data have been corrected with an improved 2-bit van Vleck correction to account for the statistics of high/low bits for each IF's data stream at each station. Thus ACCOR shouldn't be run. An autocorrelation plot for a maser (W75) scan is included in the plots for the line pass. In this case, the AUTO & CROSS plots were made before running the 2-bit van Vleck correction, since that in practice flagged Tr-* IF5-6/LL, so its being dead couldn't be illustrated. (c) BASELINE SPECTRA [*cross*] plots These plots are also the easiest place to see the lack of fringes for specific stations in specific IF/pols mentioned above in the general comments. For all baselines, the phases are reasonably horizontal across the band (near-zero residual delay). An amp(freq) plot for a maser (W75) scan is included in the plots for the line pass. (d) AMP/PHASE(t) [*ampphase*] plots See the plotdescription.txt file for explanation about the rather non-standard plotting tactics used for the continuum/line plots.