References

=1cm=1 Braun, R. 1993, VLA Scientific Memorandum No. 165: Telescope Placement at the VLA for Better Single Configuration Imaging.

=1cm=1 Briggs, D. 1995, Ph.D. thesis (NMIMT): High Fidelity Deconvolution of Moderately Resolved Sources.

=1cm=1 Cornwell, T.J., Holdaway, M.A., and Uson, J.M. 1993, AA 271, 697-713.

=1cm=1 Holdaway, M.A. 1994, VLA Scientific Memorandum No. 167: Evaluation of C Array Single Configuration Imaging.

=1cm=1 Rupen, M.P. 1997, VLA Scientific Memorandum No. 172: A Test of the CS (Shortened C) Configuration.

Figure: The inner VLA stations ($\pm2.2\rm\,km$). Those occupied in C configuration are enclosed by circles; the additional stations occupied in the 1997 CS configuration (at the expense of E12 and W12) are shown boxed,

Figure: $\delta=60^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for HA=$\pm4\rm\,hrs$, for C (upper left), CS (upper right), C-2 (lower left), and CS-2 (lower right) configurations. A point is plotted every 5.5 minutes.

Figure: Beams with IMAGR's robust=0, for a source at $\delta=60^\circ$ observed at 1.42 GHz, with HA=$\pm4$ hours. Upper left: C configuration, min/max sidelobe= $-5.1\%$/$+3.4\%$. Upper right: CS, min/max= $-3.1\%$/$+6.2\%$. Lower left: C-2, min/max= $-5.3\%$/$+4.0\%$. Lower right: CS-2, min/max= $-4.3\%$/$+7.3\%$.
Figure: $\delta=60^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz. Upper row: HA=$\pm4\rm\,hrs$ of A (left) and B (right) configurations; lower row: HA=$\pm1\rm\,hrs$ of C-2 (left) and CS-2 (right) configurations. A point is plotted every 3.5 minutes.
Figure: $\delta=80^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=60^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=40^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=20^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=0^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=-20^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=-40^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=80^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=60^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=40^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=20^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=0^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=-20^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=-40^\circ$: UV coverage ( $\pm7\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=80^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=60^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=40^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=20^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=0^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=-20^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=-40^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=80^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=60^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=40^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=20^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=0^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=-20^\circ$: UV coverage ( $\pm3\rm k\lambda$) at 1.42 GHz for a source observed for HA=$\pm4\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 3.5 minutes.
Figure: $\delta=80^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=60^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=40^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=20^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=0^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=-20^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C; upper right, CS with EW12 moved to EW3; middle left, CS with EW10 moved to EW3; middle right, CS with N10 moved to N1; lower left, CS with W10 moved to W3; lower right, CS with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=80^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=60^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=40^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=20^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=0^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: $\delta=-20^\circ$: UV coverage ( $\pm17\rm k\lambda$) at 1.42 GHz for a source observed for HA= $0.0-0.1\rm\,hrs$. The configurations are: upper left, C-2; upper right, CS-2 with EW12 moved to EW3; middle left, CS-2 with EW10 moved to EW3; middle right, CS-2 with N10 moved to N1; lower left, CS-2 with W10 moved to W3; lower right, CS-2 with W10 moved to W1. A point is plotted every 0.5 minutes.
Figure: HA=$\pm4\rm\,hrs$ simulations: CLEANed images for sequence 2, Cas A ( $D=385\rm\,arcsec$) with a total flux density of 1.605 Jy. Upper left: C configuration ( $13.2\times13.1\rm\,arcsec$); upper right: CS ( $13.5\times13.2\rm\,arcsec$); lower left: C-2 ( $13.3\times12.9\rm\,arcsec$); lower right: CS-2 ( $13.7\times13.4\rm\,arcsec$). Contours are 10, 20, ..., 90, 99% of peak.
Figure: HA=$\pm4\rm\,hrs$ simulations: difference images (simulation minus truth) for sequence 2, Cas A ( $D=385\rm\,arcsec$) with a total flux density of 1.605 Jy. Upper left: C configuration ( $13.2\times13.1\rm\,arcsec$); upper right: CS ( $13.5\times13.2\rm\,arcsec$); lower left: C-2 ( $13.3\times12.9\rm\,arcsec$); lower right: CS-2 ( $13.7\times13.4\rm\,arcsec$). Contours are $2^n\sigma$, $n$= $\pm2$, 3, 4, 5, 6, where $\sigma$ is the off-source rms noise; greyscale range is 0 to 30$\sigma$.
Figure: HA=$\pm4\rm\,hrs$ simulations: CLEANed images for sequence 32, Cyg A ( $360\times140\rm\,arcsec$) with a total flux density of 3.526 Jy. Upper left: C configuration ( $13.2\times13.1\rm\,arcsec$); upper right: CS ( $13.5\times13.2\rm\,arcsec$); lower left: C-2 ( $13.3\times12.9\rm\,arcsec$); lower right: CS-2 ( $13.7\times13.4\rm\,arcsec$). Contours are 10, 20, ..., 90, 99% of peak.
Figure: HA=$\pm4\rm\,hrs$ simulations: difference images (simulation minus truth) for sequence 32, Cyg A ( $360\times140\rm\,arcsec$) with a total flux density of 3.526 Jy. Upper left: C configuration ( $13.2\times13.1\rm\,arcsec$); upper right: CS ( $13.5\times13.2\rm\,arcsec$); lower left: C-2 ( $13.3\times12.9\rm\,arcsec$); lower right: CS-2 ( $13.7\times13.4\rm\,arcsec$). Contours are $2^n\sigma$, $n$= $\pm2$, 3, 4, 5, 6, where $\sigma$ is the off-source rms noise; greyscale range is 0 to 30$\sigma$.
Figure: HA= $0.0-0.1\rm\,hrs$ simulations: CLEANed images for sequence 2, Cas A ( $D=385\rm\,arcsec$) with a total flux density of 1.605 Jy. Upper left: C configuration ( $16.8\times13.4\rm\,arcsec$); upper right: CS ( $17.1\times14.3\rm\,arcsec$); lower left: C-2 ( $16.4\times13.6\rm\,arcsec$); lower right: CS-2 ( $16.9\times14.5\rm\,arcsec$). Contours are 10, 20, ..., 90, 99% of peak.
Figure: HA= $0.0-0.1\rm\,hrs$ simulations: difference images (simulation minus truth) for sequence 2, Cas A ( $D=385\rm\,arcsec$) with a total flux density of 1.605 Jy. Upper left: C configuration ( $16.8\times13.4\rm\,arcsec$); upper right: CS ( $17.1\times14.3\rm\,arcsec$); lower left: C-2 ( $16.4\times13.6\rm\,arcsec$); lower right: CS-2 ( $16.9\times14.5\rm\,arcsec$). Contours are $2^n\sigma$, $n$= $\pm2$, 3, 4, 5, 6, where $\sigma$ is the off-source rms noise; greyscale range is 0 to 30$\sigma$.
Figure: HA= $0.0-0.1\rm\,hrs$ simulations: CLEANed images for sequence 32, Cyg A ( $360\times140\rm\,arcsec$) with a total flux density of 3.526 Jy. Upper left: C configuration ( $16.8\times13.4\rm\,arcsec$); upper right: CS ( $17.1\times14.3\rm\,arcsec$); lower left: C-2 ( $16.4\times13.6\rm\,arcsec$); lower right: CS-2 ( $16.9\times14.5\rm\,arcsec$). Contours are 10, 20, ..., 90, 99% of peak.
Figure: Detailed quality measures for a simulated observation of Cas A with HA=$\pm4\rm\,hrs$ of C configuration (seq. 2). The data were mapped and deconvolved using IMAGR. The x-axis is the flux density of the simulation, in units of Jy/beam (bottom axis) and $\sigma$ (top axis).
Figure: The measured off-source RMS noise as a function of peak flux density. The two horizontal lines indicate the expected thermal noise in the case of no signal: the lower shows that for the long observations (HA=$\pm4\rm\,hrs$, $\sigma=0.017\rm\,mJy/beam$), the upper, that for the snapshots (HA= $0.0-0.1\rm\,hrs$, $\sigma=0.143\rm\,mJy/beam$). Cas A simulations are represented by filled circles (C, CS) and 10-pointed stars (C-2, CS-2); large Cyg A, by open boxes (C, CS) and crosses (C-2, CS-2); medium Cyg A, by the larger filled triangles (C, CS) and the larger inverted Y's (C-2, CS-2); small Cyg A, by the smaller filled triangles (C, CS) and the smaller inverted Y's (C-2, CS-2). Each point corresponds to a single simulation using IMAGR (CLEAN), before any convolutions.
Figure: The four `fidelity' measures plotted as a function of dynamic range. The dashed line corresponds to $\rm DR=FI$; note that, for most of the simulations, the on-source fidelity is well below the dynamic range. Cas A simulations are represented by filled circles (C, CS) and 10-pointed stars (C-2, CS-2); large Cyg A, by open boxes (C, CS) and crosses (C-2, CS-2); medium Cyg A, by the larger filled triangles (C, CS) and the larger inverted Y's (C-2, CS-2); small Cyg A, by the smaller filled triangles (C, CS) and the smaller inverted Y's (C-2, CS-2). Each point corresponds to a single simulation using IMAGR (CLEAN), before any convolutions.
Figure: The effect of losing two antennas: long observations (HA=$\pm4\rm\,hrs$). The ratios of the five quality measures for pairs of simulations convolved to the same beam sizes are shown. Open circles represent C-2/C; 10-pointed stars, CS-2/CS; open triangles, VCS-2/VC; inverted Y's, VCS-2/VCS. The y-axis is logarithmic, with ticks corresponding to ...0.8, 0.9, 1.0, 2, 3, 5, ...; the horizontal line represents 1.0, so points lying above this line represent simulations which improved when two antennas were dropped, while those below it got worse. Note that some $\langle FI_S\rangle$ and $\langle FI_{5\sigma}\rangle$ points may lie outside the range displayed. The x-axis shows the sequence numbers of the simulations (as defined in the tables), with vertical lines splitting the sources up between Cas A (seq. 1-6), the small Cyg A (11-14), the medium Cyg A (21-22), and the large Cyg A (31-32).
Figure: The effect of losing two antennas: snapshot observations (HA= $\pm0.0-0.1\rm\,hrs$). The ratios of the five quality measures for pairs of simulations convolved to the same beam sizes are shown. Open circles represent C-2/C; 10-pointed stars, CS-2/CS; open triangles, VCS-2/VC; inverted Y's, VCS-2/VCS. (The `V' denotes VTESS simulations.) The y-axis is logarithmic, with ticks corresponding to ...0.8, 0.9, 1.0, 2, 3, 5, ...; the horizontal line represents 1.0, so points lying above this line represent simulations which improved when two antennas were dropped, while those below it got worse. Note that some $\langle FI_S\rangle$ and $\langle FI_{5\sigma}\rangle$ points may lie outside the range displayed. The x-axis shows the sequence numbers of the simulations (as defined in the tables), with vertical lines splitting the sources up between Cas A (seq. 1-6), the small Cyg A (11-14), the medium Cyg A (21-22), and the large Cyg A (31-32).
Figure: CS vs. C configuration: long observations (HA=$\pm4\rm\,hrs$). The ratios of the five quality measures for pairs of simulations convolved to the same beam sizes are shown. Open circles represent CS/C; 10-pointed stars, CS-2/C-2; open triangles, VCS/VC; inverted Y's, VCS-2/VC-2. (The `V' denotes VTESS simulations.) The y-axis is logarithmic, with ticks corresponding to ...0.8, 0.9, 1.0, 2, 3, 5, ...; the horizontal line represents 1.0, so points lying above this line represent images which are better mapped with CS than with C, while those below are better mapped with C configuration. Note that some $\langle FI_S\rangle$ and $\langle FI_{5\sigma}\rangle$ points may lie outside the range displayed. The x-axis shows the sequence numbers of the simulations (as defined in the tables), with vertical lines splitting the sources up between Cas A (seq. 1-6), the small Cyg A (11-14), the medium Cyg A (21-22), and the large Cyg A (31-32).
Figure: CS vs. C configuration: snapshot observations (HA= $0.0-0.1\rm\,hrs$). The ratios of the five quality measures for pairs of simulations convolved to the same beam sizes are shown. Open circles represent CS/C; 10-pointed stars, CS-2/C-2; open triangles, VCS/VC; inverted Y's, VCS-2/VC-2. (The `V' denotes VTESS simulations.) The y-axis is logarithmic, with ticks corresponding to ...0.8, 0.9, 1.0, 2, 3, 5, ...; the horizontal line represents 1.0, so points lying above this line represent images which are better mapped with CS than with C, while those below are better mapped with C configuration. Note that some $\langle FI_S\rangle$ and $\langle FI_{5\sigma}\rangle$ points may lie outside the range displayed. The x-axis shows the sequence numbers of the simulations (as defined in the tables), with vertical lines splitting the sources up between Cas A (seq. 1-6), the small Cyg A (11-14), the medium Cyg A (21-22), and the large Cyg A (31-32).
Figure: Losing two antennas vs. switching from C to CS configuration: long observations (HA=$\pm4\rm\,hrs$). The ratios of the two most useful quality measures are shown, now with a linear y-axis to allow more quantitative appraisals. Symbols and axes are as in Figures -.