I don't own one but read a post on a bowhunting board that said his GPS had a message of ' no signal available' or something of that nature. Anybody got one to check it out? Thanks.

I'm not currently at home right now but they probably turned SA back on.  Selective Availability.  SA degrades the performance of 'normal' GPS units and you need a military GPS to have it get almost perfect performance.

In a time of war, SA would definately be on, then again, most people say SA is moot nowadays anyway.

Can anyone with a GPS confirm?  I'll break mine out later today when I get home.

"No signal available", means just that. unless they can block non-military recievers he was probably in a bad spot, so  he couldn't get the signal.

Out here at the airport that was the first thing we checked.  We figured we would be at war if the frequency had been switched.  At last check all was well.  Selective availability was turned off last year as many people had figured a way around it.  The military can however simply switch the transmit frequency and render the system unusable to anyone at any time.  As most civilian aircraft rely heavily on GPS navigation I suspect war would be declared before this however.  Planerench out.

Most of the military GPS receivers are off-the-shelf commericial, so SA effects them just as much as anyone else.

If they turned it off to civilian customers, it would not effect ships and planes, but it would effect rifle squads and platoons.

I just check some waypoints that I marked 6 months ago. Same,GPS working fine in Colorado.

Work with GPS daily at work.

Other than a Rotation of the Constellations, which I expect them to do regularly anyway,
Nothing out of the ordinary.

Was he standing under a tree?

If the sky/horizon is not clear of obstacles
he would not get a lock and "No signal would be available.

I am using Recievers that cost $15k apiece and I can not work under tree cover.(In the woods)
Even if I put my receiver antenna 25 feet in the air. Which you can't do with a handheld unit.
If I walk around I might find a hole but that's still unlikely.

It also depends on how "many" satellites are
over your area at that time.

When I got out to work, I have to do some mission planning to make sure that I will have the necessary "SV's"(Satellite Vehicles)
usually 3 to 8 are required to get a lock on my coordinates.
More is better, less won't work.
Spacing (telemetry) is also critical.
If all the SV's are on the horizon, it also won't work.


Del

The Army and some Navy Uses the AN PSN-11 PLGR GPS system, that can recieve encoded signal from the GPS Satalites.  In the manual (TM) it states that in time of crisis or War, the Satalites can be set to transmit only encoded signals so that civilian GPS will not work, and military ones can. I do not know about other types of military GPS, but I would expect that they would also support that feature.

Chewie

My Magellan is working fine. Eastern Mass

I lost my GPS receiver. But I believe I could locate it to within 10m anyway. I suspect it's at my brother's house.

I have a Garmin GPS III.  I just tried it and got six sats in about thirty seconds.  Looks fine to me.


Jim

I lost my GPS signal for about 5 minutes yesterday. Before that, the WAAS signal was down for about a day. Somebody is screwing around with it for some reason, or maybe it was just one of those "sh*t happens" things.

Man,

I just turned it back on inside the house, and I have three solid hits!  I've been able to lock it in while on a commercial jet, and record the airspeed.


Jim

Checked mine out yesterday and this morning back on the hunting club.  Working fine and dead on the money as usual.  

Eastern NC

Just read an alert saying we are getting "solar intrusions" twice a day which mess up satellite reception.