Lack of satelites

wildbill · Post by **wildbill** » 14 January 04 3:47 pm

Is it just my GPSr or are all the satelites on the other side of the globe during the last few weeks?
My meridian tells me that only#'s 16 and 13 are visible today at 3.45pm. What good is a gps system if you don't have enough satelites to get a position?

mick

Team Piggy · Post by **Team Piggy** » 14 January 04 7:27 pm

Hmm, Sorry to say but Geosynchrounous Orbit satellites "don't " move. They are stuck so high that they spin at the same rate the earth turns, eg, standing still.
Unless youv'e fallen off the planet, they dont go nowhere..
ohh Hang on..,,, Wait I see...

Magellan.. I think I figured it for you...

Anyway, have a look here, it gives a simple laymans terms of how it all works..

http://www.trimble.com/gps/how.html

EcoTeam · Post by **EcoTeam** » 14 January 04 9:38 pm

Team Piggy wrote:Hmm, Sorry to say but Geosynchrounous Orbit satellites "don't " move. They are stuck so high that they spin at the same rate the earth turns, eg, standing still.
Unless youv'e fallen off the planet, they dont go nowhere..
ohh Hang on..,,, Wait I see...

Magellan.. I think I figured it for you...

Anyway, have a look here, it gives a simple laymans terms of how it all works..

http://www.pbs.org/wgbh/nova/longitude/gps.html

GPS Satellites are not in Geo-Stationary orbit. They travel twice as fast as the earth rotates, and hence orbit the earth once a day (slight under by a few minutes I think). There are 6 orbital planes with 4 satellites per plane.
I think the equivalent ground speed is 4km per second or something like that. Fast little suckers!

EcoDave

EcoTeam · Post by **EcoTeam** » 14 January 04 9:50 pm

wildbill wrote:Is it just my GPSr or are all the satelites on the other side of the globe during the last few weeks?
My meridian tells me that only#'s 16 and 13 are visible today at 3.45pm. What good is a gps system if you don't have enough satelites to get a position?

mick

The satellite positions guarantee that you will be able to see at least 4 satellites from anywhere on earth at any time. So if you can't see that many, you don't have a good enough unobstructed view of the sky for whatever reason.
If you have say, two satellites reasonably overhead and two near the horizon; then it doesn't take too many small obstacles like trees or buildings in the distance to block those signals from the birds near the horizon (which will also have a lower received signal level). Atmospheric conditions also play a large part. Bingo, only two birds visible

In such cases, I'd recommend trying the Ideology receiving position

EcoDave

Team Piggy · Post by **Team Piggy** » 14 January 04 9:57 pm

Oops.. wrong info..

* Runs off with Trotter in mouth*..

Probably was right on the magellan fact though !

wildbill · Post by **wildbill** » 15 January 04 9:48 am

The satellite positions guarantee that you will be able to see at least 4 satellites from anywhere on earth at any time.

That was my understanding also but last friday and again yesterday the almanac told me that only 2 satelites were visible from my position.
The little screen that shows the location of the satelites showed only 2 satelites. This is not a signal problem, the GPSr says they are not there at all, so of course I get a little wait icon on my screen and no location info.

mick

EcoTeam · Post by **EcoTeam** » 15 January 04 10:12 am

wildbill wrote:
The satellite positions guarantee that you will be able to see at least 4 satellites from anywhere on earth at any time.
That was my understanding also but last friday and again yesterday the almanac told me that only 2 satelites were visible from my position.
The little screen that shows the location of the satelites showed only 2 satelites. This is not a signal problem, the GPSr says they are not there at all, so of course I get a little wait icon on my screen and no location info.
mick

Your problem is that you own a Magellan

Garmins don't have such problems!

EcoDave

Biggles Bear · Post by **Biggles Bear** » 15 January 04 11:07 am

wildbill wrote:
The satellite positions guarantee that you will be able to see at least 4 satellites from anywhere on earth at any time.
That was my understanding also but last friday and again yesterday the almanac told me that only 2 satelites were visible from my position.
The little screen that shows the location of the satelites showed only 2 satelites. This is not a signal problem, the GPSr says they are not there at all, so of course I get a little wait icon on my screen and no location info.

mick

What software is your Meridian running? Mine had a very similar problem until I upgraded to V 4.02, there my even be a more current version try the Magellan site.

Alby · Post by **Alby** » 15 January 04 3:16 pm

This is the only way to go..Not long ago the local fire rescue unit got lost on the back roads because there was no signal.. Magellan updates can be found here http://www.gpsinformation.org/allory/magfeat.htm

alex · Post by **alex** » 15 January 04 11:12 pm

I am running v 5.12 on my Meridian Gold, I downloaded this version mid-December from www.magellangps.com. You can also get there through Magellan Australia site, magellan.com.au .

I'm not convinced that the software was the cause of your problem though I don't have any explanation myself.

Geocaching Australia

Lack of satelites

Lack of satelites

Oink..

Re: Oink..

Re: Lack of satelites

Magellan upgrades.