GPS off by about 50 ft - Page 2

BoyNextDoor · 01-06-2005, 07:31 AM

maybe it's a goverment conspiracy thing, since they can shut down the sattelites to their liking... you never know...

ShawJohn · 01-06-2005, 08:57 AM

I have noticed that my BU-303 only gets 3 or 4 sats when on my dash but gets 7 to 9 when placed inside my sunroof. It seems to be because of the metallic film they use when tinting windscreens, even though my sunroof has a sort of metallic feeling film with millions of small round holes in it to darken it, it doesn't affect the GPS signal whereas the windscreen does.

It might be worth sticking your sensor out the sunroof or a window just to see if it improves.

Using SirF mode as opposed to NMEA also seems to increase positional accuracy and update speed if you are able to use it.

HTH

John

wi77iam · 01-07-2005, 06:06 AM

Most GPS units have a position update rate of once per second. At 45 mph, your car will travel 66 feet in one second. Your mapping software will always display the car symbol one second behind the actual position, unless it can do dead reckoning. The left/right position would not be affected.

RedGTiVR6 · 01-07-2005, 08:21 AM

Quote: Originally Posted by Skipjacks

My GPS, running i Guidance with an Earthmate receiver seems to be about 50ft off. It's got left and right fine, but stright ahead is off by about 50ft when I come to an intersection. It'll tell me to turn in 50ft, when I'm already at the intesection.

Is that just the nature of hte beast or do I need to adjust something?

could it be the earthmate reciever? I have the earthmate reciever and software (though I don't use it anymore in the car) and I noticed that I was off quite a bit as well.....though the software didn't snap to teh road.....

wondering if the reciever might have something to do with it?

liquid_smoke · 01-07-2005, 09:11 PM

i have a earthmate as well with iGuidance and the position is pretty much dead on unless im dropping sats, but thats another problem.
what gps software are you using?

Skipjacks · 01-08-2005, 02:06 AM

Quote: Originally Posted by liquid_smoke

i have a earthmate as well with iGuidance and the position is pretty much dead on unless im dropping sats, but thats another problem.
what gps software are you using?

A previous tip on making sure the GPS had a clear view of the sky in front of the car solved the problem.

I just pushed it WAY far back against the rear window and it gets sat locks from in front of the car now and that seems to have fixed the issue.

Of course the next day my motherboard went hokey. But you can't have everything, right?

alvins · 01-15-2005, 09:27 AM

I am in Sydney, Australia and have experienced the same problems over the last couple of weeks (although nothing has changed in terms of configuration). Before that everything was accurate to about 5m ie. If I am passing a road, looking at destinator at the same time it would show me passing the road. Over the last two weeks it seems to be off by about 5 secs travelling at 60km. btw. this was using NMEA.

Have tried switching to SIRF last couple of days and same problem exists. It seems the update frequency has plummetted. Note that in both cases I had 5+ satellites. I am thinking of reinstalling windows from scratch to make sure nothing funky has happened (I can't see why since no changes were made to the system).

lorenzolamas · 01-16-2005, 10:17 PM

FWIW, I bought myself the ViaMichelin Navigation Europe 1.3 (€199) and had the exact same trouble as you. The turn-by-turn guidance were always late, telling me to turn 20-30 meters after I'd made the turn, and very often the position on the map would jump insanly several hundred meters off my position. I was very very disappointed. If I made a wrong turn, the software would use 30-40 seconds to re-calculate the route (I have an Acer Ferrari 3200, AMD 64bits 2800+ CPU). It also wanted me to drive on small "walking-roads-only", roads that to my knowledged NEVER have been drivable, (small roads exclusively built for bicycling and walking). Anyway, receiveing conditions; I Usualy get 5-6 sats without external antenna (Holux 230BT), and get 9-11 with external antenna. Same story. Not knowing what was the trouble, the software or the hardware I was very confused. If I had followed some of the instructions from the software, my driving license would have gone to...well... Even my house, which have been there for 35 years don't exist according to ViaMichelin.

Anyway, I downloaded the D3 front-end by Ninja-Monkey and it's a completely different world. D3 works like a charm and is incredibly accurate. So, in my case it was clearly the useless crapy GPS software released by ViaMichelin. On the package it claims to be the only software available (in the World!) to support Palm, PPC and Win XP... I'm not sure if it works better with PPC, but with Win XP it doesn't work at all.

Hmm, long post. I was more angry with ViaMichelin than I realised(!) Sorry.

Perhaps you should try D3 and see if it works better. Just to eliminate software vs hardware probs. (Which was my point in the first place).

alvins · 01-17-2005, 06:40 PM

I am using D3.. hmm.. will have to do that reformat soon.

JPuma · 08-24-2005, 04:28 PM

Quote: Originally Posted by Tuned Vitesse

Using SirF mode as opposed to NMEA also seems to increase positional accuracy and update speed if you are able to use it.

I am using FD, are you saying I can USE both modes? I think its on NMEA now, I thought I tried SirF and didnt see any sats. Thats was before I put the BU303 on my roof anyways so I guess I'll try it again.

blckwdw · 04-30-2008, 11:07 AM

Mine is rally bad too, I get 3-4 in the back on a convertible under the plastic window

sporty_drew · 04-30-2008, 03:19 PM

holy thread bump

I was just seaching GPS and realized how old this is.