[evlatests] Big S-band Pulses ...

[Dan Mertely]

The on-line checks I've done, + the FCC allocation table suggests
that it is either a earth resource satellite radar (although Ken
brought up some good points relating to "hang-time" and power
consistency), or a military radar of some kind.  It appears, for
example, that the USAF AWACS radar illuminator operates in exactly
that frequency range (eg:
http://www.comsearch.com/newsletter/archiveWP/WirelessPulseJan02.html)

The FCC frequency table also lists footnote US342 which does provide
some (limited) protection for RA, stating:
-------------------------------------------------
US342 In making assignments to stations of other services to which the 
bands:
...
3260-3267 MHz*
3345.8-3352.5 MHz*
...
are allocated (*indicates radio astronomy use for spectral line 
observations), all practicable steps shall be taken to protect the radio 
astronomy service from harmful interference. Emissions from space-borne 
or airborne stations can be particularly serious sources of interference 
to the radio astronomy service (see ITU Radio Regulations at Nos. 4.5 
and 4.6 and Article 29).
-------------------------------------------------
The 3260 MHz lower limit is probably close enough if we wanted to
try to get frequency coordination with the USAF.

I could put-in a request with the DoD Frequency Coordinator for this
area & find out if they have any NM-based systems operating at
3250/3206 MHz, and if so, if he could put us in contact with the
operator.  Do you think that would be useful?  How often has the RFI
showed up?  I've tried looking for it with our monitoring systems
(both the Omni-antenna RF-EMS and our 1.5m parabolic, AZ/EL mounted
RF-DFS system) without success.  If it is not up often it may not be
worth chasing.
-Mert


On 6/17/2015 9:26 AM, Rick Perley wrote:
>      Dan:
>
>      Have you found a plausible origin of the one-time 10-second pulses
> seen at 3206 and 3250 MHz?
>
>      Rick