How to Calibrate GPS

[stainless]

How do I calibrate my GPS.
For some reason on some roads it thinks I am 50 to 100 feet off the side of the road. Then some roads I am fine.
It is real annoying when the navigation lady keeps telling me to turn left at the intersection of 1st and broad, 2nd and broad, etc. for every side street I pass because it thinks I am 100 feet to the left of where I actually am.
I have never had this problem with any GPS I have ever used so what gives..

 

[bcromwell]

How do I calibrate my GPS.
For some reason on some roads it thinks I am 50 to 100 feet off the side of the road. Then some roads I am fine.
It is real annoying when the navigation lady keeps telling me to turn left at the intersection of 1st and broad, 2nd and broad, etc. for every side street I pass because it thinks I am 100 feet to the left of where I actually am.
I have never had this problem with any GPS I have ever used so what gives..

There is no calibration, Either you don't have the phone close enough to windows to get a good lock on the gps's or the map data is wrong for the road you are on.

 

[stainless]

Well I hope it is close enough to the windows as it is when I am driving.
How does one contact Google to tell them their maps are wrong then

 

[shaggymatt]

I'm in my office right now, so I can't get GPS coverage. If you install GPS Status, take a look and see how many satellites you're resolving. It used to be that you needed so many satellites to get 3d coverage, not sure if that still applies. Of course the more satellites the better your accuracy. About 15 years ago it was standard GPS, and then differential GPS came along which was the more accurate, upsale, model back in the day. Now all models are essentially differential based and accurate typically to within ~3 meters.

 

[barry99705]

How do I calibrate my GPS.
For some reason on some roads it thinks I am 50 to 100 feet off the side of the road. Then some roads I am fine.
It is real annoying when the navigation lady keeps telling me to turn left at the intersection of 1st and broad, 2nd and broad, etc. for every side street I pass because it thinks I am 100 feet to the left of where I actually am.
I have never had this problem with any GPS I have ever used so what gives..

What kind of car do you have?? Some cars have a coating on the windshield that blocks ir radiation from the sun to help keep the interior cool. This coating will block or seriously degrade the gps signal.

 

[michaelk]

your location may be perfect but some of google maps are way off.

there's a section of I-95 in North Carolina where I drove through people's laws for several miles a few months ago with my old phone

the map data the Droid uses in the map application is somehow NOT the most recent. There's some streets in my neighborhood that are 2-3 years old. if i use the browser and go to maps.google.com they show up (like they have for many months). But using the map application on the phone they still dont exist.

if you want to check your gps- then you can use gps status from the market- it's free. It will show green dots for the differnt sats. If you get 4 green dots it can get a 3D lock. I can't think of anyway you could get 4 or more sat's locked and wouldn't get an accurate 3D fix. (maybe there's a way but i can't think of it at the moment)

 

[barry99705]

your location may be perfect but some of google maps are way off.

there's a section of I-95 in North Carolina where I drove through people's laws for several miles a few months ago with my old phone

the map data the Droid uses in the map application is somehow NOT the most recent. There's some streets in my neighborhood that are 2-3 years old. if i use the browser and go to maps.google.com they show up (like they have for many months). But using the map application on the phone they still dont exist.

if you want to check your gps- then you can use gps status from the market- it's free. It will show green dots for the differnt sats. If you get 4 green dots it can get a 3D lock. I can't think of anyway you could get 4 or more sat's locked and wouldn't get an accurate 3D fix. (maybe there's a way but i can't think of it at the moment)

A 3d fix isn't really needed, a 2d fix will place you correctly on the map, the 3d will place you correctly on the map, and give you altitude. Unless you're in a plane, that part isn't really important. The more satellites you have locked the better your position will be though, so 3d is handy to know since you need at least four satellites for that.

 

[Doit2it]

there's a section of I-95 in North Carolina where I drove through people's laws for several miles a few months ago with my old phone

You really should stay off peoples lawns, no matter what the GPS says.

 

[michaelk]

A 3d fix isn't really needed, a 2d fix will place you correctly on the map, the 3d will place you correctly on the map, and give you altitude. Unless you're in a plane, that part isn't really important. The more satellites you have locked the better your position will be though, so 3d is handy to know since you need at least four satellites for that.

all true but didn't want to clutter it up and confuse people further that 3 says will give a 2D fix and then further explain that geometry teaches us all that a lock with distance information from 2 sats should be enough to narrow us down to 2 points in space and since only one is likely to be on the surface of the earth explain that theoretically 2 sats alone should cut the mustard. But that minute clock variances on each bird are enough due to the speed radio waves to force the additional 3rd satellite to be required for 2D and the 4th sat to be needed for 3D.

I figured saying "4 sats are needed" was simplier. But as you pointed out I thought it wouldn't be totally accurate without explaining that is a 3D lock so i tossed that in to as a disclaimer


Goofing aside- good point for sure that the more sats the more accurate. Google maps kind of reports that when you hit 'my location'- as I beleive it draws a shaded blue circle and then says "your location within X meters" where it adjusts X based on the number of sats in view- or before a sat lock based on the power needed to talk to the nearest cell.

 

[michaelk]

You really should stay off peoples lawns, no matter what the GPS says.

Sssshhhhhhh - that's between us.

LAUGHING

 

[stainless]

The problem is with Google them selves.
Yesterday I drove through town and the GPS map showed me WAYYYY off.
But the satellite overlay showed me really close.
Google does not have their layers aligned correctly......
This is true for both standard and mobile.

 

[jenli]

Don't recall reading about it anywhere...

 

[stainless]

Don't recall reading about it anywhere...

About what ? WAAS ?

Not sure how that could help if the layers are misaligned from Google

 

[michaelk]

anyone found a place to notify google of map errors like this?

 

[Redflea]

I used Google Maps on my BB to go to a restaurant, and it was about 1/4 mile off on the restaurant's location. The address was correct, but Google Maps had it located far from the actual building.

It ain't a perfectly mapped world.

GMaps also always wants me to drive home via a private drive that is actually behind my home...good thing I can find my house on my own.

 

[jenli]

No...WAAS won't fix layers. It may not
even fix the offset in the base map.

But WAAS could at least make your
GPS position more accurate.

 

[stainless]

Yes
In google maps (standard) if you right click on the location at the bottom of the box it has a notify google of error selection.
You can drag the marker to the correct location and notify them.

 

[michaelk]

Yes
In google maps (standard) if you right click on the location at the bottom of the box it has a notify google of error selection.
You can drag the marker to the correct location and notify them.

any idea how to tell them that the map in the navigate app is wrong but the one in the google maps is correct?

 

[marvo]

Google latitude, sometimes places me accurately (usually when i am at home), and some other times when im at home places me a couple of streets away (but always in exactly the same eroneous place).
Both my dot and my GF's dot are shown some way to the east and a little way to the north of our actual positions. (I have a Desire, she has a Blackberry)
I noticed when you dowload some apps from the market, that the preinstallation blurb says something about calibrating the GPS i think, by waving the phone in a figure of eight motion. I do not jest!

 

[Lock-N-Load]

GPS Test is the bomb for testing and seeing signals and strength on a real time live bar chart.

 

[CBLJazz]

i use the app GPS STATUS and its great.

it has a compass, tells spped, notates how many gps satellites I'm being tracked by.s a

To calibrate my unit i turn ihe phone on the side and rotate clock wise and counter clockwise.
Although this action looks a little silly it improved MY gps accuracy.


btw, in conjunction with my gps i use PLACES DIRECTORY to find nearby poi's.
both great gps tools.

 

[sblack]

Here's a link from Google Maps Help - Fix an error on Google Maps
I've used it to report several street name errors and also misalignment of streets.

 

[branches]

Your compass needs to be calibrated. In Google Maps (that's what I use) your blue dot's beam will be wide and not aligned with your walking direction, and if navigating by car your car's arrow is pointing in the wrong direction.

To calibrate, open your maps app.T Thentrace a horizontal figure 8 with your phone several times until your compass is calibrated. My device says to hold the phone so that it's standing on it's long edge relative to the ground while tracing the figure 8.

Your car's arrow should thereafter point straight ahead. If you're navigating as a pedestrian, the blue dot's beam (in Google Maps) should be narrow and point in the right direction.