Or a harmonic from, e.g., a television broadband preamp. I have seen interference from those, although usually at other frequencies, a number of times. And I concur, this has to be an L1 interference problem. While it could be within the 20 MHz primary passband, I strongly suspect broadband rather than carrier noise. 73 gerry On Wed, Nov 7, 2012 at 10:07 AM, Peter Laws <[log in to unmask]> wrote: > They don't use the military "P-code", so it's the L1 frequency, 1575.42 MHz > that is being affected. Anything +/- 50 MHz or so would be suspect. Could > be a spur from an IF on something using a higher frequency, too. > > > On 11/07/12 09:50, Zac Flamig wrote: >> >> Just in case any of you guys know something... >> >> Zac >> >> >> -------- Original Message -------- >> Subject: Fwd: GPS Interference >> Date: Wed, 07 Nov 2012 05:33:35 -0600 >> From: Bob Staples <[log in to unmask]> >> To: [log in to unmask] >> >> >> >> Please note the email from Forest Mitchell ( WFO) and advice me of anyone >> you know or that may be conducting experiments that would interfere with >> the GPS signal ? >> >> Thanks, >> Bob D Staples >> >> >> -------- Original Message -------- >> Subject: GPS Interference >> Date: Wed, 07 Nov 2012 04:20:17 -0600 >> From: Forrest Mitchell <[log in to unmask]> >> To: Bob Staples <[log in to unmask]> >> CC: David Andra <[log in to unmask]>, [log in to unmask], >> [log in to unmask], John Pike <[log in to unmask]>, Daryl Williams >> <[log in to unmask]>, Doug Speheger <[log in to unmask]>, Rick >> Smith <[log in to unmask]> >> >> >> >> In the past week, we have been experiencing interference with acquiring >> a GPS signal for the radiosondes we launch for Upper Air flights. The >> GPS signal is critical towards acquiring accurate wind data aloft. >> >> The interference is centered around the NWC, as measured by coworkers >> using a variety of GPS devices. The interference occurs during the >> afternoons, affecting us >> during our launch window from 5-6:30 pm. It then disappears around 7 >> pm. There is no interference during the morning flights. >> >> Is there some experiment being performed by someone within the NWS >> community that could be causing the interference? We would appreciate >> your efforts to find the source >> so that we may create a solution to allow us to perform our mission in >> its entirety. Thank you. >> >> >> >> >> >> >> > > > -- > Peter Laws / N5UWY > National Weather Center / Network Operations Center > University of Oklahoma Information Technology > [log in to unmask] > College of Architecture, Regional and City Planning, MRCP '16 > -------------------------------------------------------------------------- > Feedback? Contact my director, Matt Younkins, [log in to unmask] Thank you!