Summary of 21-Sep-95 ==================== * Steps in XY phases in previous DQO runs were the result of an error in the setup sched file. * The new blank field (19:08:19,-58:56:15) is reasonably blank. At 21 cm, the strongest source is ~19 mJy (apparent flux), about 18 arcmin from the field centre. * The baseline 1-2, polarisation YX, frequency 1, was bad throughout the run. This correlator block was OK soon after (~6 hrs) the DQO run finished. The correlator had been reprogrammed by this time. * 21 cm on-source images improve significantly if we calibrate each channel independently. There appears to be some problem (low level interference?) around f=1328 MHz (channel 9 in the frequency decimated dataset). * Off-axis polarimetric respose at 13 cm was about a factor of 6 worse than the that at 3 cm at a similar place in the primary beam (7 arcmin at 13 cm, 2 arcmin at 3 cm). * Closure errors at 6 cm do not show much trend with channel number. ======================================================================== Summary of Data Quality Observations of 21/09/95 ------------------------------------------------ Array: 0.75D Fields: Calibrator 1934-638 Offset Calibrator 1934_a Blank Field 1934_b Frequencies: 1344 2368 4800 8640 MHz The offset calibrator field was offset in RA,DEC from 1934-638 by 0,-420 arcsec at 1344 MHz 0,-420 arcsec at 2368 MHz 0,-120 arcsec at 4800 MHz 0,-120 arcsec at 8640 MHz See the end of this document for an explanation of terms and the filenaming convention. ------------------------------------------------------------------------ Flagging statistics after ATLOD ------------------------------- File XX% YY% XY% YX% ---- --- --- --- --- 1934-638.1344 1934-638.2368 1934-638.4800 1934-638.8640 1934_a.1344 1934_a.2368 1934_a.4800 1934_a.8640 1934_b.1344 1934_b.2368 1934_b.4800 1934_b.8640 ---------------------------------------------- Closure phase statistics for the point sources File Th.Phase Sigmas ---- -------- ------ 1934-638.1344 0.012 23.83 1934-638.2368 0.016 6.94 1934-638.4800 0.027 1.37 1934-638.8640 0.056 2.18 1934_a.1344 0.012 45.17 1934_a.2368 0.020 12.05 1934_a.4800 0.029 1.34 1934_a.8640 0.073 1.85 --------------------------------------- Post-reduction flagging statistics ---------------------------------- File XX% YY% XY% YX% ---- --- --- --- --- 1934-638.1344-cal 21.84% 21.84% 21.84% 21.84% 1934-638.2368-cal 7.24% 7.24% 7.24% 7.24% 1934-638.4800-cal 10.58% 10.58% 10.58% 10.58% 1934-638.8640-cal 2.87% 2.87% 2.87% 2.87% 1934_a.1344-cal 15.15% 15.15% 15.15% 15.15% 1934_a.2368-cal 1.13% 1.13% 1.13% 1.13% 1934_a.4800-cal 9.20% 9.20% 9.20% 9.20% 1934_a.8640-cal 2.05% 2.05% 2.05% 2.05% 1934_b.1344-cal 10.20% 10.20% 10.20% 10.20% 1934_b.2368-cal 2.81% 2.81% 2.81% 2.81% 1934_b.4800-cal 9.47% 9.47% 9.47% 9.47% 1934_b.8640-cal 2.01% 2.01% 2.01% 2.01% ======================================================================== File Th. RMS Sigmas D.R. Pk Val ---- ------- ------ ---- ------ 1934-638.1344-low.icln-x 2.58E-04 8.37 6944 15.007 1934-638.1344-low.qmap 2.58E-04 5.73 4 0.007 1934-638.1344-low.umap 2.58E-04 5.63 5 0.007 1934-638.1344-low.vmap 2.58E-04 3.38 4 0.003 1934-638.2368-low.icln-x 2.90E-04 9.21 4333 11.585 1934-638.2368-low.qmap 2.90E-04 3.15 6 0.005 1934-638.2368-low.umap 2.90E-04 3.41 5 0.005 1934-638.2368-low.vmap 2.90E-04 2.97 4 0.004 1934-638.4800-low.icln-x 2.99E-04 3.11 6270 5.825 1934-638.4800-low.qmap 2.99E-04 1.35 5 0.002 1934-638.4800-low.umap 2.99E-04 1.28 5 0.002 1934-638.4800-low.vmap 2.99E-04 1.14 5 0.002 1934-638.8640-low.icln-x 2.94E-04 1.81 5336 2.840 1934-638.8640-low.qmap 2.94E-04 1.11 4 0.001 1934-638.8640-low.umap 2.94E-04 1.13 4 0.001 1934-638.8640-low.vmap 2.94E-04 1.28 4 0.001 1934-638.1344-full.icln-x 9.46E-05 16.27 9745 15.004 1934-638.1344-full.qmap 9.46E-05 7.16 5 0.004 1934-638.1344-full.umap 9.46E-05 7.27 5 0.004 1934-638.1344-full.vmap 9.46E-05 5.36 7 0.003 1934-638.2368-full.icln-x 1.01E-04 10.62 10848 11.582 1934-638.2368-full.qmap 1.01E-04 4.32 6 0.003 1934-638.2368-full.umap 1.01E-04 4.36 6 0.003 1934-638.2368-full.vmap 1.01E-04 5.44 5 0.003 1934-638.4800-full.icln-x 8.85E-05 5.23 12577 5.825 1934-638.4800-full.qmap 8.85E-05 1.55 6 0.001 1934-638.4800-full.umap 8.85E-05 1.47 5 0.001 1934-638.4800-full.vmap 8.85E-05 1.52 6 0.001 1934-638.8640-full.icln-x 8.61E-05 2.94 11219 2.839 1934-638.8640-full.qmap 8.61E-05 1.19 4 0.000 1934-638.8640-full.umap 8.61E-05 1.20 4 0.000 1934-638.8640-full.vmap 8.61E-05 1.62 4 0.001 1934_a.1344-full.icln-x 9.47E-05 26.78 5214 13.221 1934_a.1344-full.qmap 9.47E-05 15.49 8 0.011 1934_a.1344-full.umap 9.47E-05 15.22 6 0.008 1934_a.1344-full.vmap 9.47E-05 5.85 9 0.005 1934_a.2368-full.icln-x 9.67E-05 19.35 4579 8.571 1934_a.2368-full.qmap 9.67E-05 123.32 14 0.165 1934_a.2368-full.umap 9.67E-05 85.66 7 0.055 1934_a.2368-full.vmap 9.67E-05 60.15 10 0.058 1934_a.4800-full.icln-x 8.70E-05 4.63 12991 5.229 1934_a.4800-full.qmap 8.70E-05 4.71 21 0.008 1934_a.4800-full.umap 8.70E-05 2.63 6 0.001 1934_a.4800-full.vmap 8.70E-05 1.78 7 0.001 1934_a.8640-full.icln-x 8.43E-05 2.62 9425 2.080 1934_a.8640-full.qmap 8.43E-05 19.43 17 0.028 1934_a.8640-full.umap 8.43E-05 11.45 7 0.006 1934_a.8640-full.vmap 8.43E-05 19.96 7 0.012 1934_b.1344-full.imap 9.18E-05 9.70 7 0.007 1934_b.1344-full.qmap 9.18E-05 1.72 4 0.001 1934_b.1344-full.umap 9.18E-05 1.13 5 0.000 1934_b.1344-full.vmap 9.18E-05 0.99 5 0.000 1934_b.2368-full.imap 9.74E-05 3.26 4 0.001 1934_b.2368-full.qmap 9.74E-05 1.10 5 0.001 1934_b.2368-full.umap 9.74E-05 1.04 5 0.000 1934_b.2368-full.vmap 9.74E-05 1.00 5 0.000 1934_b.4800-full.imap 8.78E-05 1.19 9 0.001 1934_b.4800-full.qmap 8.78E-05 1.03 5 0.000 1934_b.4800-full.umap 8.78E-05 1.04 4 0.000 1934_b.4800-full.vmap 8.78E-05 1.02 4 0.000 1934_b.8640-full.imap 8.50E-05 1.04 5 0.000 1934_b.8640-full.qmap 8.50E-05 0.99 4 0.000 1934_b.8640-full.umap 8.50E-05 0.98 5 0.000 1934_b.8640-full.vmap 8.50E-05 1.01 4 0.000 ======================================================================== Explanation of Terms: --------------------- XX%,YY%,XY%,YY% Percentage of XX, XY, YX and YY correlations flagged (excluding on-line flagging and shadowing). Th.Phase The theoretical closure phase (in degrees) based on thermal noise arguments (for the 5-minute time averaging used). Th. RMS The theoretical RMS in an image based on thermal noise arguments. Sigmas The factor by which the relevant meausre exceeds either of the above two theoretical levels. Ideally this should be 1. D.R. Dynamic range of an image, defined as the ratio of the peak absolute value divided by the RMS. For the CLEANed Stokes-I images of the calibrators, the RMS is evaluated outside the inner quarter of the image. Otherwise the RMS is evaluated over the entire image. Pk Val Peak value in an image in Jy. Explanation of File names: -------------------------- File names are of the form FIELD.FREQ Raw visibility data, giving the field name and observing frequency. FIELD.FREQ-cal Calibrated/flagged visibility data. FIELD.FREQ-low.TYPE Low resolution image, imaging the entire primary beam. TYPE gives the Stokes parameter and whether the image is CLEANed ("cln") or a dirty image ("map"). FIELD.FREQ-full.TYPE Full resolution image, but imaging only a subportion of the primary beam. TYPE is as above.