Simulating the visibilities and imaging

Simulating the visibilities and imaging

Logged on 07/06/2009 04:17:52 PM

Once we've built the tree it is executed and the visibilities are written to the DATA column of the Measurement Set.

Make an image in the usual way and examine it, the second fainter source should be apparent beneath the sidelobe structure of the central source.

One thing you might have noticed is how the image in the PURR log is upside-down compared to the image in your favourite FITS viewer. I think this is down to how Python handles images versus how the FITS format handles images. For Python the (0,0) pixel is at the top left corner, whereas a FITS file thinks it's at the lower left. PURR uses a Python routine to render the FITS files into web-friendly PNGs, as well as to perform all the stats and produce the histograms.

Data products

SSSC17_WSRT.MS.DATA.channel.1ch.fits (header)

0-full.png0-hist-full.png
0-hist-zoom.png
data range:-0.216665,4.9749
size:1x1x1024x1024
mean:-0.00525255
sigma:0.124948
clipping:95%
clip range:-0.216665,0.214275