28 Jul 2012 03:42
28 Jul 2012 04:30
Re: Lightsquared questionfor SFO area....
On Fri, Jul 27, 2012 at 09:42:49PM -0400, Brian, WA1ZMS wrote: > Does anyone know if there is ANY recent active Lightsquared testing taking > place in the SFO area of the US? > > > > I'm dealing with a day-job issue with GPS clocks in the Bay Area showing > "GPS unlocked" errors from 3rd party equipment. Do you have a good SA available and some broadband antennas... And perhaps some logging program like John Mile's SSM ? -- -- Dave Emery N1PRE/AE, die@... DIE Consulting, Weston, Mass 02493 "An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either."
28 Jul 2012 06:34
Re: Lightsquared questionfor SFO area....
On 7/27/12 6:42 PM, Brian, WA1ZMS wrote: > Does anyone know if there is ANY recent active Lightsquared testing taking > place in the SFO area of the US? > > Very unlikely.. they've lost their experimental license. > > I'm dealing with a day-job issue with GPS clocks in the Bay Area showing > "GPS unlocked" errors from 3rd party equipment. > > there are myriad sources of interference out there. Jammers are a BIG problem in urban areas (truckers and cab drivers use them to defeat their GPS based tracking systems and time clocks). there's a great set of articles over the past few months in GPS World about it. > > > > > > -Brian, WA1ZMS > > >(Continue reading)
28 Jul 2012 06:53
Re: Lightsquared questionfor SFO area....
Interesting that they use jammers. The guys on the ambulances just wrap the antennas with the foil from burger wrappers or the like. On Jul 28, 2012, at 0:34, Jim Lux <jimlux@...> wrote: > On 7/27/12 6:42 PM, Brian, WA1ZMS wrote: >> Does anyone know if there is ANY recent active Lightsquared testing taking >> place in the SFO area of the US? >> >> > > Very unlikely.. they've lost their experimental license. > >> >> I'm dealing with a day-job issue with GPS clocks in the Bay Area showing >> "GPS unlocked" errors from 3rd party equipment. >> >> > > > there are myriad sources of interference out there. Jammers are a BIG problem in urban areas (truckers and cab drivers use them to defeat their GPS based tracking systems and time clocks). > > there's a great set of articles over the past few months in GPS World about it. > > >> >> >> >>(Continue reading)
28 Jul 2012 07:18
Re: Lightsquared questionfor SFO area....
Jim- That's one thing I was afraid of, but did not yet mention to our mgmt. team. But if Light squared lost their Part 5 license, then I can take them off the list. It's a complicated problem that due to the nature of it, I cannot discuss on the reflector. But I'm involved via remote reporting from techs out in the field and their daily reports and conference calls. So I just need to "due engineering diligence" as I try and help them. I expect my butt will be on a plane next week unless I can identify a 3rd party vendor equipment problem. THANKS! -Brian, WA1ZMS -----Original Message----- From: time-nuts-bounces@... [mailto:time-nuts-bounces@...] On Behalf Of Jim Lux Sent: Saturday, July 28, 2012 12:35 AM To: time-nuts@... Subject: Re: [time-nuts] Lightsquared questionfor SFO area.... On 7/27/12 6:42 PM, Brian, WA1ZMS wrote: > Does anyone know if there is ANY recent active Lightsquared testing > taking place in the SFO area of the US?(Continue reading)
28 Jul 2012 10:32
Re: Lightsquared questionfor SFO area....
We have about 25 different GPSDOs running from four cheap antennae on the roof in Los Gatos right next to Hwy 17, and have not noted any unusual outages at all, even during the recent solar flare. I guess any truckers with jammers on hwy 17 pass by so fast we don't notice anything. Bye, Said Sent from my iPad On Jul 27, 2012, at 22:18, "Brian, WA1ZMS" <wa1zms@...> wrote: > Jim- > > That's one thing I was afraid of, but did not yet mention to our mgmt. team. > But if Light squared lost their Part 5 license, then I can take them off the > list. > It's a complicated problem that due to the nature of it, I cannot discuss on > the reflector. > > But I'm involved via remote reporting from techs out in the field and their > daily reports and conference calls. > So I just need to "due engineering diligence" as I try and help them. > > I expect my butt will be on a plane next week unless I can identify a 3rd > party vendor equipment problem. > > THANKS! > >(Continue reading)
28 Jul 2012 16:09
Re: Lightsquared questionfor SFO area....
On 7/28/12 1:32 AM, Said Jackson wrote: > We have about 25 different GPSDOs running from four cheap antennae on the roof in Los Gatos right next to Hwy 17, and have not noted any unusual outages at all, even during the recent solar flare. > > I guess any truckers with jammers on hwy 17 pass by so fast we don't notice anything. > I think the notable problems at Newark airport were because the jammer containing vehicles were sitting around in one place. http://www.gpsworld.com/government/personal-privacy-jammers-12837 is one among many articles about it.
28 Jul 2012 06:56
Re: Lightsquared questionfor SFO area....
I've had a graph logging on my HP3816A in San Jose. I see one big glitch on 7/27 ~17:00 UTC. I don't know if it unlocked, nor if it was from something received, or some jump in my hardware. Other than that one jump, I don't see anything unusual over the last week or so. There must be others around here who also have been logging GPSDO's. On 7/27/2012 6:42 PM, Brian, WA1ZMS wrote: > Does anyone know if there is ANY recent active Lightsquared testing taking > place in the SFO area of the US? > > > > I'm dealing with a day-job issue with GPS clocks in the Bay Area showing > "GPS unlocked" errors from 3rd party equipment. > > > > > > > > -Brian, WA1ZMS > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@... > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.(Continue reading)
28 Jul 2012 08:26
Re: Lightsquared questionfor SFO area....
This is one well documented example of an earlier unintentional jamming incident..... _http://www.gpsworld.com/gnss-system/signal-processing/the-hunt-rfi-776_ (http://www.gpsworld.com/gnss-system/signal-processing/the-hunt-rfi-776) Regards Nigel GM8PZR In a message dated 28/07/2012 02:43:23 GMT Daylight Time, wa1zms@... writes: Does anyone know if there is ANY recent active Lightsquared testing taking place in the SFO area of the US? I'm dealing with a day-job issue with GPS clocks in the Bay Area showing "GPS unlocked" errors from 3rd party equipment. -Brian, WA1ZMS _______________________________________________ time-nuts mailing list -- time-nuts@... To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.(Continue reading)
28 Jul 2012 08:55
Re: Lightsquared questionfor SFO area....
Nigel- I remember that event. This issue I'm remotely dealing with now seems to be limited to a specific local area bounded by a few km. So local QRM is possible. On Saturday the techs will install all new GPS antennas with integrated band-pass filters. Conf call on Saturday night at 6pm my time will produce more date. -Brian, WA1ZMS -----Original Message----- From: time-nuts-bounces@... [mailto:time-nuts-bounces@...] On Behalf Of GandalfG8@... Sent: Saturday, July 28, 2012 2:27 AM To: time-nuts@... Subject: Re: [time-nuts] Lightsquared questionfor SFO area.... This is one well documented example of an earlier unintentional jamming incident..... _http://www.gpsworld.com/gnss-system/signal-processing/the-hunt-rfi-776_ (http://www.gpsworld.com/gnss-system/signal-processing/the-hunt-rfi-776) Regards Nigel GM8PZR(Continue reading)
28 Jul 2012 09:32
Re: Lightsquared questionfor SFO area....
Hi Brian: Would you please let me know which antennas they will be using and if this solves the problem? Thanks, Ron -----Original Message----- From: time-nuts-bounces@... [mailto:time-nuts-bounces@...] On Behalf Of Brian, WA1ZMS Sent: Friday, July 27, 2012 11:55 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Lightsquared questionfor SFO area.... Nigel- I remember that event. This issue I'm remotely dealing with now seems to be limited to a specific local area bounded by a few km. So local QRM is possible. On Saturday the techs will install all new GPS antennas with integrated band-pass filters. Conf call on Saturday night at 6pm my time will produce more date. -Brian, WA1ZMS -----Original Message----- From: time-nuts-bounces@...(Continue reading)
28 Jul 2012 17:30
Re: Lightsquared questionfor SFO area....
The filters won't help with intentional on-frequency jamming. I assume the filters are there to reduce the effect of out of band signals on the AGC. (As the hams say, desense.) It seems to me a good market for next generation GPSs is spoof and/or RFI detection. -----Original Message----- From: "Ron Ward" <n6idlron@...> Sender: time-nuts-bounces@... Date: Sat, 28 Jul 2012 00:32:46 To: <wa1zms@...>; 'Discussion of precise time and frequency measurement'<time-nuts@...> Reply-To: Discussion of precise time and frequency measurement <time-nuts@...> Subject: Re: [time-nuts] Lightsquared questionfor SFO area.... Hi Brian: Would you please let me know which antennas they will be using and if this solves the problem? Thanks, Ron -----Original Message----- From: time-nuts-bounces@... [mailto:time-nuts-bounces@...] On Behalf Of Brian, WA1ZMS Sent: Friday, July 27, 2012 11:55 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Lightsquared questionfor SFO area.... Nigel- I remember that event. This issue I'm remotely dealing with now seems(Continue reading)
28 Jul 2012 15:19
Re: Lightsquared questionfor SFO area....
Brian, I have four GPSDO systems running and logging on a hill West of Redwood City with a view of the South Bay. Let me know if I can help. Craig McCartney 160 Montalvo Road Palomar Park, CA 94062 -----Original Message----- From: time-nuts-bounces@... [mailto:time-nuts-bounces@...] On Behalf Of Brian, WA1ZMS Sent: Friday, July 27, 2012 6:43 PM To: Time-Nuts Subject: [time-nuts] Lightsquared questionfor SFO area.... Does anyone know if there is ANY recent active Lightsquared testing taking place in the SFO area of the US? I'm dealing with a day-job issue with GPS clocks in the Bay Area showing "GPS unlocked" errors from 3rd party equipment. -Brian, WA1ZMS _______________________________________________ time-nuts mailing list -- time-nuts@... To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.(Continue reading)
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