Are The Satellites Down?

MrRubberGloves · Posted: Tue Jul 13, 2004 5:14 pm Post subject: Are The Satellites Down?

Just wondered as I cannot get any satellite signal on my TT Go and have just been to my taxi and the computer which my firm uses has GPS also seems to be not working as I could log into any area I wanted instead of it throwing me back into the correct area.

PS, this has happened before where there was no satellite signal due to some terrorist alert in America and all satellites were apparently turned off.

Anyone know of anything?

Crying or Very sad

Wilko · Regular Visitor Joined: Nov 17, 2003 Posts: 203

mines been working perfectly all day, Rikaline 6030 bluetooth and TT3, been getting 9-10 sats

MrRubberGloves · Posted: Tue Jul 13, 2004 5:31 pm Post subject:

Sods law, they seem to be working again and have checked with my taxi and they are working.

Sorry for the alarm.

Embarassed

It must of been a North West thing.

MrRubberGloves · Posted: Tue Jul 13, 2004 5:33 pm Post subject:

BTW they were down (if that was the problem) for around half an hour to an hour, so some of you office bound people may of been unaware.

Parky · Posted: Tue Jul 13, 2004 6:11 pm Post subject:

What time was this Question

MrRubberGloves · Posted: Tue Jul 13, 2004 6:13 pm Post subject:

Parky · Posted: Tue Jul 13, 2004 6:22 pm Post subject:

I was on my way back from "Sunny Scunny" (Scunthorpe) and had a full compliment of Sats all the way around that time. Put it down to another one of life's little mysteries

mgibbs · Posted: Tue Jul 13, 2004 7:13 pm Post subject:

I don't think they're ever down - they have multiple redundant satellites in the constellation in case of failure.

MikeB · Posted: Tue Jul 13, 2004 8:08 pm Post subject:

I suspect that it was just some local interferance. I have some logs showing good strong signals all day (in Essex).
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Mike Barrett

sland · Regular Visitor Joined: Mar 19, 2004 Posts: 144

There are 25 or so satellites, each independant of the others. It used to be that the US degraded the lot (to civil users anyway). Since about 2002 (IIRC) they have altered the way Selective Availability (SA) works. It used to be that SA was enabled all the time and that was what caused the "no better than 100m accuracy" for Civilian users. Military GPS didn't suffer from that as they access two frequencies not one like civil users so could "subtract" SA from the signal. The Americans have SA setup now so that it can be enabled on a regional basis which is why we now benefit from the approx 4m accuracy we see on a regular basis. However, at any time they see fit that accuracy could be degraded and you wouldn't know.

It is therefore unlikely that all the satellites were "off" this afternoon. Poss just one of those "it was a dark and stormy night" situations:)

HTH?
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Rgds,

Mike

sland · Regular Visitor Joined: Mar 19, 2004 Posts: 144

More info on SA here -> http://www.igeb.gov/sa.shtml if you have trouble sleeping (and I was wrong, SA was turnmed off in 2000 not 2002)
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Rgds,

Mike

nej · Posted: Wed Jul 14, 2004 8:53 am Post subject:

Check out this http://www.schriever.af.mil/GPSSUPPORTCENTER/ site for GPS Outages.

Almost every day at least one satellite is unavailable, but as there are plenty more to take it's place you don't notice.

You can even join a mailing list to get warnings on these (NANU's) from http://www.navcen.uscg.gov/ here

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