Inaccurate Satelite Navigation

[Chris.S]

Has anyone else had problems with their Sat Nav being inaccurate ?

(I have a problem where I can arrive at a junction and the sat nav will show that I haven't reached it)

[jenners]

Sometimes I have experienced this - I thought I was driving too fast for it to keep up .

Doesn't happen all the time but seem to be noticing it more recently. Bit of a long shot but I'm going to see what happens when I change my tyres since there's an option to say you've replaced the tyres :?:

[dazzab69]

Originally posted by jenners

Sometimes I have experienced this - I thought I was driving too fast for it to keep up .

Doesn't happen all the time but seem to be noticing it more recently. Bit of a long shot but I'm going to see what happens when I change my tyres since there's an option to say you've replaced the tyres :?:

Eh ? I though it worked by the satelites knowing where you are ! Is there really a tyre change option ?

[jenners]

Eh ? I though it worked by the satelites knowing where you are ! Is there really a tyre change option ?

Yip - there's definately an option to say the tyres have been changed.

[vince-com]

other way to do it, is calibrating it, you've got an option in the menu, choose a crossroad or else, stop your car and correct it on the map, as that the GPS will be fine.

I've done it once on the IS200, worked perfectly

[Chris.S]

I've already tried that Vince-go a mile up the road and its back to how it was before

[vince-com]

Spock we've got a problem…

Normally, a GPS needs 3 satelites to have the right position, on the screen you've got a red signal (one), a blue signal (two) and the green one showing that your GPS is catching 3 different signals to make the proper calibration of your position.

Did you try to calibrate it without having houses, big trees, etc etc around?

[Chris.S]

Yes I've tried it before,might give it another go though

[SteveAudioX]

my sat nav is the worst thing ever!!! i have changed my factory sat nav unit for an alpine one, running on the factory screen now. it's not the software either. its just the worst thing ever!!!! takes me the wrong way, the long way... everything but the right way! it's absolutely useless and not worth the money i paid for it.........................!!!

[Andy_IS200]

Not really experienced a problem with mine, the countdown approaching the junction helps telling you how many yards so even when I'm blasting along I have a good idea when to tuen, however having said that it can get confusing if there are two exits very close to one another. My biggest gripe is that there is not facility to request shortest route mixing major and minor routes.

[JMRussell]

I could seriously get upset by somethings. My sat nav has always been great, always spot on no problems. Then I read your query. No problem for a couple of days and then mine starts wandering off a bit and no quite being with the road. I reset it a couple of times but no avail. Reset it the other evening and now everything is OK again.

I know when sat nav was first about there was a problem with accuracy cause the US being paranoid had made it so just in case the enemy used it against them. That was of course some years ago but what with 9-11 and Iraq what do we know!

[L3X JG]

Sorry to hi jack your topic guys but the lexus sat nav is one of the best sat nav's avaliable. Even the non dvd.. Have you got an option in there to see how many sats you are reciving?... it takes 4 sat's to plot you point, you may have some thing metalic covering the gps antena. I will try and find out where it is based or if some one knows please post i 'm guessing it may be on the rear shelf or dash.The gps antena needs to see straight up, it can see through glass but not always tinted glass. Also maybe the speed pule has gone down but most likely it is the gps sig. Remember must have 4 sat's...

I hope this is of some help

now i'm late

(edited because of profanity)

[Steve]

i did not understand that last post :(

[djanderso]

Is the Sat Nav antenna not on top of the dash next to the auto light sensor? :?:

[Rodders_UK]

That's certainly where it is on my car.

Also, I thought you only needed 3 sats to get a fix (I think the Lexus (Denso) system is a 3-channel system??)

[Chris.S]

The Sat Nav antenna on a IS200 is under the rear parcel shelf

[Monster-Mat]

sat nav can work down to 2 satalites,but obviously the more satalites there is the more accurate the pinpoint...............................however GPS has a in built inacuracy,and during times of un-ease, or tension you may find it will become slightly a little fibber;)

there is plans for europe to launch its own "GPS" system

[Chris.S]

Mine tends to be between 20 and 50 yards out Mat.Eveytime I reach a junction the pionter on the screen displays I haven't reached it but it sometimes works if I drive slowly (less than 30mph)

[L3X JG]

As we fit all makes of sat nav including Alpine, VDO, Kenwood, panasonic, Pioneer etc we would like to clear up the fact that you need at least 4 sats to plot your position with any kind of accuracy. 8 is ideal, but 4-6 is what is needed for anywhere near half decent...

[vince-com]

Not sure about that, a GPS needs 3 satelites at least to make a proper triangulation of your position on earth, with 2 is unable to locate you, it will only point a situation knowing your last position (inertial)

Another thing is the inertial when you're under a bridge for example, it knows the last position and your cap, so it will follow until having a new sat signal to follow.

just check the GPS indicator on your screen, no GPS means no signal, red means one sat signal, blue means two sat signals, green 3 sat signals & triangulation able.

[Rodders_UK]

Originally posted by L3X JG

As we fit all makes of sat nav including Alpine, VDO, Kenwood, panasonic, Pioneer etc we would like to clear up the fact that you need at least 4 sats to plot your position with any kind of accuracy. 8 is ideal, but 4-6 is what is needed for anywhere near half decent...

I agree with Vince - it's basic trigonometry - you only need 3 points in order to establish position in a 2-dimensional plane (i.e. on the ground).

[ricky_is200]

I just wish I had this problem, then at least I would have sat nav...:(

[vince-com]

On the DVD one I just discovered inside the data bank, restaurant from 3 stars ones…to Mc Donalds.

How can Lexus let point to a McDo ???

That's what we call the "Mal bouffe" down there:lol: