[evlatests] Ku-band RFI -- how bad it can be...

[Rick Perley]

     I distributed yesterday a 'waterfall' plot of severe X-band RFI, 
affecting the upper half of the band.

     Unsurprisingly, it extends well in Ku band.  Attached here is a 
similar plot, for the spectral range 12 -- 14 GHz.  This is a very short 
baseline (N1 x N2), with 1 second averaging, and 2 MHz spectral 
resolution.  Time runs vertically, frequency horizontally.  The X-axis 
is labeled in terms of spectral window and channel.

     The source is 3C273 -- the 'dark' side of the plot, at the higher 
frequencies, is RFI free, and is at a level of 18 Jy.  The grey-scale is 
logarithmic, with the maximum at 567 Jy.

     The RFI cuts off at 12.7 GHz.  Above that (at least to 16 GHz), the 
spectrum is really clean.

     Rick


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