G.P.S. Question

id. painter · 01-13-2003, 07:19 AM

While reading the instruction manual for my G.P.S. i noticed a sentance that said . . Heavy fog or cloud cover can interfere with the G.P.S. ability to communicate with the satelite.
QUESTION.. Have any of you ever had this happen. Clouds or fog so thick that your G.P.S. wouldnt work?? id. p.

Miss B Haven · 01-13-2003, 07:28 AM

News to me id. I don't knwo what "heavy" is but I certainly have been out in the clouds and fog. Worked fine. Is this a handheld? Maybe I better read my manual!

id. painter · 01-13-2003, 08:30 AM

My G.P.S. is a Magellan 315 (?) . I have used it in some heavy fog with no problems. That sentance has always made me wonder when and if it will happen.
Did my "compass and a chimp " post show up? When i click on it all i get is an empty screen. id. p.

fish assassin · 01-13-2003, 09:07 AM

ID:

Hit your "reload" radio button ... when you go into a subject and
then back out to the menu it sometimes does wierd things. I see
9 new threads from you in 10 days lsited on the menu page right now.

-assAssin-

Sensei-san · 01-13-2003, 09:17 AM

A GPS receiver is receiving a signal rated in the microwatt levels. Compare this to your local AM or FM station that broadcasts in the kilowatt levels. Fog or water vapor dampens any radio signal. The thicker the fog or water vapor blanket, the more damping of the signal will occur. Another good reason to have a compass, they work in any weather condition.

Popeye · 01-13-2003, 09:31 AM

I actually had my GPS blink on me about 4 years ago in heavy-heavy fog. I was just making my approach into Yaquina! Luckily I had been watching my compass, and realized the problem immediately. I quickly turned the boat back out to sea, and after a few minutes, the GPS started working again, and I headed in safely. Don't know if it was the fog or not, but another good reason to watch that compass regularly!

Miss B Haven · 01-13-2003, 09:40 AM

Hmmm... also sounds like another darn good reason to have that radar up and tracking! This GPS/fog thing is new to me. Good info to know guys.

Just when you need it most! [img]graemlins/1zhelp.gif[/img] :shocked:

[img]graemlins/berry.gif[/img]

Popeye · 01-13-2003, 09:45 AM

Mel,
I was in the other boat that day....no radar on that one!

fish assassin · 01-13-2003, 09:47 AM

I've lost my GPS *lots* of times because of fog/cloudy conditions ...
'course, I'm out there more than most ...

Another thing to think about ... If (when) we start hostilities over "there",
GPS may be shut down on a temporary basis for National Security reasons.
As we get closer to going to war, it is always a good idea to keep an eye on
your compass reading home. You just may not have the old "plastic jesus" to
show you the way!!

-assAssin-

Sensei-san · 01-13-2003, 10:01 AM

Actually assAssin the NSA may turn off the SA feature entirely. Too many troops in the original Gulf War had mom and dad send them off the shelf GPS units that they were afraid that having SA on would result in too much collateral damage. You can check whether or not SA is on by using the EPE (Estimated Position Accuracy) feature of most GPS's. You are right though, they might blink GPS at crucial times if they go to war.

01-13-2003, 10:11 AM

Would I rely on
a Compass- maybe
a GPS- maybe
a Radar- Yes
Eyes and ears- usualy

Miss B Haven · 01-13-2003, 10:29 AM

Sensai- I believe SA has been turned off for quite some time now. Doesn't mean it won't get turned back on in the future but I belive it's been of for a year or two. I was right on top of the bouys all season last year. :smile: A little too close a couple of times in the fog. :shocked: I set up my waypoints about 50 feet off. I think I'll reset to a 100 or so next season. :smile:

Hmmm... now that I think about it, I've got DGPS so I wouldn't know if they were playing with SA unless they turn of fthe local correction too! :depressed: [img]graemlins/berry.gif[/img]

[ 01-13-2003, 11:31 AM: Message edited by: Miss B Haven ]

Pilar · 01-14-2003, 07:34 AM

I've been lucky and have not experienced the fog interference problem. In fact, since I got the 12 satellite antenna, it hasn't dropped out, ever.

The only reason to worry about your GPS is that the system is not officially commisioned. If the unit you are using has issues, get rid of it and buy something reliable. As they said on Usta fish, 'If you don't believe your instrumentation, repair it or replace it.' I'm sure this 'unofficial' status is a liability issue as the manual for every unit you can buy goes to great lengths to disclaim the use of GPS for navigation. Some units even flash a message screen disclaimer on boot up.

SA has been disabled since the 20 yr rollover in Aug 2001. Every 20 years the seconds counter exceeds the space available for it in the registers. So the system has a 20 year clock with time in seconds. A complete reset of the system is done every 20 years. I watched the plastic Jesus that day in Aug, 2001 and never saw a blink.

The government can and will if necessary disrupt the time signals, count on it and use this resource accordingly.

[ 01-14-2003, 08:38 AM: Message edited by: Pilar ]