Hi I'd say that: HiNOTICE ADVISORY TO NAVSTAR USERS (NANU) 2013053 SUBJ: SVN34 (PRN04) FORECAST OUTAGE SUMMARY JDAY 246/1717 - JDAY 247/0029 1. NANU TYPE: FCSTSUMM NANU NUMBER: 2013053 NANU DTG: 040030Z SEP 2013 REFERENCE NANU: 2013052 REF NANU DTG: 291526Z AUG 2013 SVN: 34 PRN: 04 START JDAY: 246 START TIME ZULU: 1717 START CALENDAR DATE: 03 SEP 2013 STOP JDAY: 247 STOP TIME ZULU: 0029 STOP CALENDAR DATE: 04 SEP 2013 2. CONDITION: GPS SATELLITE SVN34 (PRN04) WAS UNUSABLE ON JDAY 246 (03 SEP 2013) BEGINNING 1717 ZULU UNTIL JDAY 247 (04 SEP 2013) ENDING 0029 ZULU. 3. POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV MILITARY - GPS OPERATIONS CENTER at HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541, COMM 719-567-2541, gpsoperationscenter@us.af.mil, HTTPS://GPS.AFSPC.AF.MIL MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514, COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL is indeed trustworthy. It could / might cause issues world wide. A lot depends on how people write their firmware and how many sats are in view. Apparently it was not an issue to normal navigation firmware. The basic question being - did they write the firmware to take the "best 2 out of 3" if things looked odd. Given all the issues with multi path I would think they would. Bob On Sep 6, 2013, at 11:36 PM, "John C. Westmoreland, P.E." <john@westmorelandengineering.com> wrote: > Fellow Time Nuts: > > Is this a site to be trusted?: > > http://adn.agi.com/SatelliteOutageCalendar/SOFCalendar.aspx > > Regards, > John W. > > > On Fri, Sep 6, 2013 at 6:41 PM, John C. Westmoreland, P.E. < > john@westmorelandengineering.com> wrote: > >> Lisa, >> >> Thanks for this update. How many Resolution-T receivers are out there? >> >> Not to go off on another tangent - but I have heard something about 'GPS >> jamming during the America's Cup'. Hmmm. >> >> Regards, >> John Westmoreland >> >> >> >> On Fri, Sep 6, 2013 at 8:54 AM, Lisa Perdue <perdue.lisa@gmail.com> wrote: >> >>> Trimble has confirmed to us that the nonstandard outage on PRN 4 (SVN 34) >>> may have caused the Resolution-T receivers to perform a reset and then >>> return to normal operation. They are investigating the cause but it does >>> explain why only some people experienced the event. Other Trimble >>> receivers >>> and other manufacturers seem unaffected. >>> >>> >>> On Thu, Sep 5, 2013 at 10:34 PM, Brian, WA1ZMS <wa1zms@att.net> wrote: >>> >>>> Guys- >>>> >>>> Please forgive me for the BW...... >>>> >>>> My day-job mgmt. has also asked me today if I knew of any US regional >>> GPS >>>> "issues", as we too have had several reports of >>>> our customers systems going into Rb hold-over on or about the 4th of >>> Sept. >>>> Only fact I can find is that SVN 4 was noted as >>>> an issue via: >>> http://adn.agi.com/SatelliteOutageCalendar/SOFCalendar.aspx >>>> But that can't be the root cause. >>>> >>>> At work, I am now the "go-to-guy" for ANYTHING GPS related since I'm a >>>> Time-Nut and we have customers who depend on >>>> GPS timing for their comm. systems; and for reasons I cannot go into >>> here >>>> on this reflector. >>>> >>>> So like Brad.....I too have anecdotal reports of issues. The sky is not >>>> falling, nor was it a serious issue. >>>> However if anyone has info that they cannot share via the reflector, a >>>> private reply would be much appreciated. >>>> I am not looking for info that cannot be openly shared. But if anyone >>> has >>>> hint or clue, I would much appreciate it. >>>> >>>> BTW....my GPS receivers here in VA seemed to have had no issue. Go >>> figure. >>>> >>>> -Brian, WA1ZMS >>>> >>>> >>>> >>>> -----Original Message----- >>>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On >>>> Behalf Of Brad Dye >>>> Sent: Wednesday, September 04, 2013 6:14 PM >>>> To: Time Nuts >>>> Subject: [time-nuts] GPS outage? >>>> >>>> Readers of my newsletter are reporting a strange interruption of their >>> GPS >>>> reception yesterday -- mainly in the northeastern US but also in SC. >>> This >>>> is >>>> my first day on this mailing list -- for a while -- so I don't know if >>> this >>>> has been discussed or reported previously. Has anyone else noticed >>> this? We >>>> are trying to find out is there was some sort of system-wide issue or >>> maybe >>>> if it was local interference possibly caused by those GPS jammers that >>> some >>>> of the truckers have been using. >>>> >>>> By the way, my newsletter is mostly about Paging, and we use GPS/DOs to >>>> keep >>>> the paging transmitters (in simulcast mode) synchronized and on >>> frequency. >>>> >>>> Best regards, >>>> >>>> Brad Dye, K9IQY >>>> Editor, Wireless Messaging News >>>> P.O. Box 266 >>>> Fairfield, IL 62837 USA >>>> Telephone: 618-599-7869 >>>> Skype: braddye >>>> http://www.braddye.com >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

On 9/6/13 8:36 PM, John C. Westmoreland, P.E. wrote: > Fellow Time Nuts: > > Is this a site to be trusted?: > > http://adn.agi.com/SatelliteOutageCalendar/SOFCalendar.aspx > > Regards, > John W. > AGI are the folks who make and sell STK (Satellite Took Kit, I believe) which has a dominant position in the marketplace for doing analyses of satellite orbits, visibility, planning, etc. They have all sorts of hooks for their product: antenna patterns, link calculations, etc. I prefer SOAP (Satellite Orbit Analysis Program) from Aerospace Corporation (free for government use, maybe even for non-profits), but STK is a much, much bigger commercial player. Both products have fairly steep learning curves.