Summary of Data Quality Observations of 05/10/95 ------------------------------------------------ Array: 0.75C 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 Notes: * 1934-638 was tracked to where it set. The poor phase stability at the low elevations showed up in the poorer image statistics at 6 and 3 cm, and the resultant strips in the images. Closure phase was still OK. * Again there appears to be interference at 1320 MHz (channel 10 in the decimated dataset). * We are gaining a somewhat better understanding of instrumental polarimetric response (especially at 6 cm). 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 0.7% 0.4% 0.5% 0.6% 1934-638.2368 0.5% 0.5% 0.5% 0.5% 1934-638.4800 0.0% 0.0% 0.0% 0.0% 1934-638.8640 0.0% 0.0% 0.0% 0.0% 1934_a.1344 0.1% 0.0% 0.1% 0.1% 1934_a.2368 0.1% 0.1% 0.1% 0.1% 1934_a.4800 0.0% 0.0% 0.0% 0.0% 1934_a.8640 0.0% 0.0% 0.0% 0.0% 1934_b.1344 0.1% 0.3% 0.2% 0.1% 1934_b.2368 0.1% 0.1% 0.0% 0.2% 1934_b.4800 0.6% 0.4% 0.5% 0.5% 1934_b.8640 0.6% 0.4% 0.4% 0.5% ---------------------------------------------- Closure phase statistics for the point sources File Th.Phase Sigmas ---- -------- ------ 1934-638.1344 0.013 29.15 1934-638.2368 0.018 6.67 1934-638.4800 0.033 1.39 1934-638.8640 0.064 1.77 1934_a.1344 0.013 33.92 1934_a.2368 0.021 10.81 1934_a.4800 0.030 1.33 1934_a.8640 0.075 1.67 --------------------------------------- Post-reduction flagging statistics ---------------------------------- File XX% YY% XY% YX% ---- --- --- --- --- 1934-638.1344-cal 20.3% 20.3% 20.3% 20.3% 1934-638.2368-cal 10.7% 10.7% 10.7% 10.7% 1934-638.4800-cal 6.4% 6.4% 6.4% 6.4% 1934-638.8640-cal 5.3% 5.3% 5.3% 5.3% 1934_a.1344-cal 10.6% 10.6% 10.6% 10.6% 1934_a.2368-cal 1.6% 1.6% 1.6% 1.6% 1934_a.4800-cal 7.9% 7.9% 7.9% 7.9% 1934_a.8640-cal 6.1% 6.1% 6.1% 6.1% 1934_b.1344-cal 8.8% 8.8% 8.8% 8.8% 1934_b.2368-cal 4.4% 4.4% 4.4% 4.4% 1934_b.4800-cal 4.1% 4.1% 4.1% 4.1% 1934_b.8640-cal 7.3% 7.3% 7.3% 7.3% ======================================================================== File Th. RMS Sigmas D.R. Pk Val ---- ------- ------ ---- ------ 1934-638.1344-low.icln-x 2.57E-04 9.31 6267 15.012 1934-638.1344-low.qmap 2.57E-04 5.85 5 0.008 1934-638.1344-low.umap 2.57E-04 6.00 5 0.007 1934-638.1344-low.vmap 2.57E-04 4.02 5 0.006 1934-638.2368-low.icln-x 2.93E-04 11.09 3571 11.582 1934-638.2368-low.qmap 2.93E-04 3.50 5 0.005 1934-638.2368-low.umap 2.93E-04 4.05 5 0.006 1934-638.2368-low.vmap 2.93E-04 3.49 4 0.004 1934-638.4800-low.icln-x 3.02E-04 7.61 2534 5.820 1934-638.4800-low.qmap 3.02E-04 1.41 4 0.002 1934-638.4800-low.umap 3.02E-04 1.47 5 0.002 1934-638.4800-low.vmap 3.02E-04 1.11 5 0.002 1934-638.8640-low.icln-x 3.12E-04 3.14 2896 2.835 1934-638.8640-low.qmap 3.12E-04 0.96 4 0.001 1934-638.8640-low.umap 3.12E-04 0.99 4 0.001 1934-638.8640-low.vmap 3.12E-04 1.20 4 0.002 1934-638.1344-full.icln-x 9.39E-05 19.43 8223 15.008 1934-638.1344-full.qmap 9.39E-05 6.07 6 0.003 1934-638.1344-full.umap 9.39E-05 6.21 6 0.003 1934-638.1344-full.vmap 9.39E-05 8.42 8 0.006 1934-638.2368-full.icln-x 1.01E-04 9.13 12591 11.582 1934-638.2368-full.qmap 1.01E-04 3.55 6 0.002 1934-638.2368-full.umap 1.01E-04 3.97 6 0.002 1934-638.2368-full.vmap 1.01E-04 5.63 7 0.004 1934-638.4800-full.icln-x 8.82E-05 5.73 11520 5.825 1934-638.4800-full.qmap 8.82E-05 1.32 5 0.001 1934-638.4800-full.umap 8.82E-05 1.54 5 0.001 1934-638.4800-full.vmap 8.82E-05 1.61 8 0.001 1934-638.8640-full.icln-x 8.79E-05 6.44 5016 2.837 1934-638.8640-full.qmap 8.79E-05 1.07 5 0.000 1934-638.8640-full.umap 8.79E-05 1.14 5 0.000 1934-638.8640-full.vmap 8.79E-05 1.41 5 0.001 1934_a.1344-full.icln-x 9.26E-05 30.19 4736 13.234 1934_a.1344-full.qmap 9.26E-05 15.92 11 0.016 1934_a.1344-full.umap 9.26E-05 20.11 4 0.008 1934_a.1344-full.vmap 9.26E-05 8.78 11 0.009 1934_a.2368-full.icln-x 9.68E-05 13.32 6662 8.590 1934_a.2368-full.qmap 9.68E-05 96.40 16 0.148 1934_a.2368-full.umap 9.68E-05 78.06 6 0.046 1934_a.2368-full.vmap 9.68E-05 53.96 16 0.083 1934_a.4800-full.icln-x 8.74E-05 4.34 14025 5.318 1934_a.4800-full.qmap 8.74E-05 4.46 21 0.008 1934_a.4800-full.umap 8.74E-05 2.07 5 0.001 1934_a.4800-full.vmap 8.74E-05 1.85 10 0.002 1934_a.8640-full.icln-x 8.70E-05 3.88 6428 2.169 1934_a.8640-full.qmap 8.70E-05 15.59 17 0.023 1934_a.8640-full.umap 8.70E-05 10.22 8 0.007 1934_a.8640-full.vmap 8.70E-05 19.57 11 0.018 1934_b.1344-full.imap 9.47E-05 9.61 6 0.006 1934_b.1344-full.qmap 9.47E-05 4.48 3 0.001 1934_b.1344-full.umap 9.47E-05 1.99 4 0.001 1934_b.1344-full.vmap 9.47E-05 1.06 4 0.000 1934_b.2368-full.imap 1.03E-04 2.51 4 0.001 1934_b.2368-full.qmap 1.03E-04 1.16 5 0.001 1934_b.2368-full.umap 1.03E-04 1.12 5 0.001 1934_b.2368-full.vmap 1.03E-04 1.01 5 0.001 1934_b.4800-full.imap 8.89E-05 1.17 9 0.001 1934_b.4800-full.qmap 8.89E-05 1.03 4 0.000 1934_b.4800-full.umap 8.89E-05 1.05 5 0.000 1934_b.4800-full.vmap 8.89E-05 0.98 5 0.000 1934_b.8640-full.imap 9.10E-05 1.06 4 0.000 1934_b.8640-full.qmap 9.10E-05 1.03 4 0.000 1934_b.8640-full.umap 9.10E-05 1.04 5 0.001 1934_b.8640-full.vmap 9.10E-05 1.04 5 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.