SSSC7 PURR Log

Stewart Gleadow, gleadows@unimelb.edu.au, University of Melbourne

Using calico-view-ms.py

Quickly checking the MS contains data similar to expected. Visibility amplitude for differentsome baselines shown in the image below. Shows varying amplitude that would match the gain errors that we have inside knowledge about.

Dirty image also created. For a linearly polarised signal at 45 degrees, expect the Stokes I and U images to contain the source signal, as seen in the histogram.

Since the actual antennas are vertically and horizontally polarised, there is also a small amount of leakage into Stokes Q and V. These histograms have a noise-like histogram rather than actually containing source data.

Using calico-wsrt.py

Copied in the LSM that was used to create this simulation to use for calibration.

Set up to calibrate and use MeowLSM, and generated the residuals (see compile and runtime settings below).

Inspector:G panel showed slowy varying gain amplitudes, but no variance in the phase.

Make an image of all Stokes parameters, with 512 pixels and imaging 30 arcmin. Average all freq channels. Make a dirty image.

See image below. Expect only nano Jansky noise to remain. Since the original polarisation axis is at 45 degrees, the noise is present in all Stokes parameters (compared with SSSC6, where the vertically polarised signal meant that U and V had no signal at all).