4.ii: Imaging the new residuals

4.ii: Imaging the new residuals

Logged on 07/10/2009 01:03:15 PM

Open the 'TDL Exec' menu again. It should remember how we like our images, but double check anyway. Expand the 'make an image from this MS' menu, make sure we're imaging the CORRECTED_DATA channel which now contains residual visibilities, i.e.what's left after we've subtracted the source and corrupted the data with the G-Jones.

Click 'make a dirty image' and you should end up with something like the image below.

The image due to the residual calibration errors has noise-like emission on the nano-Jansky level. Of course this is an idealised simulation which does not contain the thermal noise which pervades all real observations, does not contain numerous or complex radio sources, and is also free from all but the simplest of data corruptions. Nonetheless the techniques we have employed to arrive at this image are fundamental, and all calibration is basically an extension of these ideas.

Data products

SSSC1_WSRT.MS.CORRECTED_DATA.channel.1ch.fits (header)

0-full.png0-hist-full.png
0-hist-zoom.png
data range:-1.63509e-09,1.92534e-09
size:1x1x512x512
mean:-1.86599e-11
sigma:3.83043e-10
clipping:95%
clip range:-7.48457e-10,7.64029e-10