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

[Rick Perley]

     Dan:

     While you have your tables handy, what is broadcasting between 
17.300 and 17.664 GHz.  I see a lot of wideband stuff in this band.  The 
RFI is in 9 adjacent bands, each 40 MHz wide,  the middle one is empty 
(i.e., clean of RFI).

     Rick

On 10/18/19 1:56 PM, Dan Mertely wrote:
> Hi Rick. I'm surprised that the band seems worse than before.
> The low Ku band, "Fixed Satellite, (space-to-earth)" (read GSO)
> allocation is 11.7-12.2 GHz.  Then from 12.2-12.7 is the broadcasting
> satellite down-link band.  Above that are the uplinks, which we are
> unlikely to see (none nearby).  So 11.7-12.7 GHz should have been
> very noisy for years.  -Mert
>
> On 10/18/2019 11:40 AM, Rick Perley via evlatests wrote:
>>      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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