GPS accuracy seems low

[Guest cacoe]

I don't know if I'm over estimating how accurate gps should be but even with 10 satellites in view, I'm only getting accuracy between 30-70 metres.

Is that normal or is something wrong?

I'm using JJ9 with assisted GPS off as advised.

Edited February 15, 2011 by cacoe

[Guest Elvis Sawdust]

I find my GPS accuracy is variable, best is 7m worst 3000m, not some thing I'd rely on too much for finding my way around :D

[Guest cacoe]

I assume 3000m would be assisted gps at work, without the ability to actually get an actual GPS lock.

I understand that happens but when relying sole on gps, I'd expect the accuracy to generally fall under 10m, assuming there were enough satellites in view...

[Guest ricer]

Using GPS Info it shows that I usually have about 35-45% signal with the satellites most of the time. But using the navigator, it seems fine and perfectly usable.

[Guest cacoe]

Does google maps try to snap you to the nearest road? When I'm walking around on my garden, it only ever shows me as being outside my house on the street...

[Guest MidaMilunk]

I don't know if I'm over estimating how accurate gps should be but even with 10 satellites in view, I'm only getting accuracy between 30-70 metres.

Is that normal or is something wrong?

I'm using JJ9 with assisted GPS off as advised.

I have experienced kinda low GPS precision - but the fix time is really damn fast! I have never seen this fast GPS before!

Anyway, it works quite well alltogether, no problem navigating in-car - but much better open-air! 2M accuracy is easy to achieve, GPS averaging comes into <1m very soon (under, or approx. 10 samples).

I had been using the original (hungarian) fw. for a long time - I am using a private (also hungarian) 2.2 version now, I will check the GPS things again!

Edited February 15, 2011 by MidaMilunk

[Guest cacoe]

So if I were to walk around a bit more while using it, it would slowly become more accurate due to more samples being taken? I don't drive btw, I always use it on foot.

Edited February 15, 2011 by cacoe

[Guest mrbloggs]

So if I were to walk around a bit more while using it, it would slowly become more accurate due to more samples being taken? I don't drive btw, I always use it on foot.

yep, it takes a few minutes to zero in on you

I've done a bit of testing on the fone, and I'm impressed. Used osmtracker to record tracks, some up to 10 miles long, the fone just placed on the passanger seat of my car. Checked against the OSM data, and its spot on, very accurate. Outside away from buildings I'm getting 1 metre accuracy, indoors as I type this I'm getting 3 to 4 metres.

[Guest cacoe]

So, is this accuracy which builds up something which stays cached or does it need an amount of usage every time to become more accurate?

[Guest etjazz]

Using GPS Info it shows that I usually have about 35-45% signal with the satellites most of the time. But using the navigator, it seems fine and perfectly usable.

Where can i find this GPS info program? Searched the market but nothing came up... ?

[Guest cacoe]

I use gps status

[Guest cacoe]

So I decided to take a short walk to the end of the street and back. I walked down the pavement in a smooth line (I wasn't drunk btw!) and this is what I get

(street names removed, would have posted satalite view but even more annoying to remove names)

Normal or freaky?

In satellite view, it has me walking through a host of different houses, rather than on the pavement, and on the return journey, it has me walking in the middle of the street.

The sampling seems to be going a bit crazy.

[Guest Phoenix Silver]

So I decided to take a short walk to the end of the street and back. I walked down the pavement in a smooth line (I wasn't drunk btw!) and this is what I get

(street names removed, would have posted satalite view but even more annoying to remove names)

Normal or freaky?

In satellite view, it has me walking through a host of different houses, rather than on the pavement, and on the return journey, it has me walking in the middle of the street.

The sampling seems to be going a bit crazy.

not normal

i already have tried this and i was always in the middle of the street

[Guest cacoe]

So, what could be wrong? I hope it's a software thing! I hate waiting for returns... could it be my ROM of choice? Anything like this been reported it JJ9 before?

Just trust the no1 feature I was excited about to be broken on my handset :D

Edited February 15, 2011 by cacoe

[Guest Phoenix Silver]

So, what could be wrong? I hope it's a software thing! I hate waiting for returns... could it be my ROM of choice? Anything like this been reported it JJ9 before?

Just trust the no1 feature I was excited about to be broken on my handset :D

i have fibblesan r8a installed

a quick way to see if it is a software prob

nandroid backup of jj9

quick install of fibblesan rom

[Guest cacoe]

Just to be certain, were you using my tracks by google when you did that test? I ask this because good maps seems to snap me to the street (most the time)

i have fibblesan r8a installed

Can't seem to find that in the roms forum btw, not even through a search for fibblesan :D

edit- Ohhh it's flb-froyo! got it. I was already eyeing this ROM up after some talk that JJ might be dead and seeing as I'm going to attempt a nandroid restore on my brothers on friday, I have to try to get everything working before hand hopefully!

Edited February 15, 2011 by cacoe

[Guest spannerz]

So I decided to take a short walk to the end of the street and back. I walked down the pavement in a smooth line (I wasn't drunk btw!) and this is what I get

(street names removed, would have posted satalite view but even more annoying to remove names)

Normal or freaky?

In satellite view, it has me walking through a host of different houses, rather than on the pavement, and on the return journey, it has me walking in the middle of the street.

The sampling seems to be going a bit crazy.

Normal for a drunken person I'd say

:D

[Guest Phoenix Silver]

Normal for a drunken person I'd say

:D

yes :D

here

[Guest spannerz]

So, is this accuracy which builds up something which stays cached or does it need an amount of usage every time to become more accurate?

From a cold start I believe that the GPS has to download an ephemeris data which has a limited life of useful data and also the Almanac data, once this data has been received then subsequent continued use should mean better accuracy as more satellites are received and accuracy inreases. Problems such as 'canyoning' where you're in a city centre with tall buildings obstructing views to the skies can reduce accuracy as can trees and other things in the way.

Apparently most recent GPS devices have some almanac data in them but guess some further data is required for accurate fixes and variations etc.

I find my SF can sometimes get an accurate fix even indoors near a window very quickly and yet other times it takes forever even though it's showing perhaps 7 to 10 reasonable strength satellites in view. Sometimes pressing the top power button to turn off/on and the GPS then kicks into life, or closing/reopening an application can make GPS suddenly work.

I've found the same trick of turning off/on makes my bluetooth connect to car parrot hands free kit also!

Something about going to standby then back on makes apps and things jump into life on mine!

:D

Edited February 15, 2011 by spannerz

[Guest MidaMilunk]

Normal or freaky?

Well, not so easy to say! No GPS, even the professional ones produce exact position, not even a single one, not mentioning a whole sequence. I think this is the tracker's job to smooth the raw GPS data.

I have tracked stg similar than you using Navitel while walking, but the other track was perfect with "GPStracker light" travelling by bus. I am to test GPST also while walking... Earlier I also tracked my way on other smartphones, using different software products, and always experienced different results, and it was always better if I was travelling faster - but the results was dependent on the tracker sw as well!

I also considered this GPS a fast but inaccurate one, but later on I have found that it is not inaccurate, just somehow "too fast" :D

[Guest cacoe]

Reflashed with flb-froyo. I also increased min time between points in my tracks to max accuracy (adaptive)

Results seem better but they're still anything but perfect

(note, this walk lasted over an hour, I found a stray dog and called the rspca, waited for them to come and get the dog too!)

there's still an element of jitter and though the tracking on the road is definitely much better, it still has my location quite offset from where I was actually walking.

Also, I seemed to have totally lost gps signal after walking back through the trees and didn't get it back the whole walk back after that.

[Guest cacoe]

So, hows this looking? Should I return the handset?

It's fairly accurate for getting an initial location but never even close to perfect, so it's good for locational services but not so good for tracking/directions. I can stand in the middle of my 40ft x 20ft back garden that is out in the open, other than my 2 story house next to it, next to a bunch of fields and it still places me on the garden of someone across the street from me. Probably about 30 metres away. I can walk the perimeter of my garden and it records no activity at all as though I'm not moving.

If it's a matter of "it depends how important GPS is to you" then I'd say, yes, a fair bit.

Edited February 17, 2011 by cacoe

[Guest mrbloggs]

So, hows this looking?

Not too good. Here's a gpx track I loaded into google earth, and as you can see, was surrounded by buildings, the fone placed on the passenger seat of my car,

[Guest cacoe]

I went on the back garden for a quick test again earlier, walked around and it was still useless. I came back in and put the phone on my desk and left it for a couple of hours, forgetting I'd left my tracks recording my movement still.

Considering it had been sat near a window for such a long time, the results are interesting...

I don't know if this sheds any light on the problem at all, but honestly, it really has been sat doing nothing apart from my walk around the back garden for around 5 minutes.

[Guest derek500]

I use the Golfshot paid app and I'm impressed with the accuracy. It measures distances from where I'm standing, to specific parts of the hole. It's normally within a couple of yards of what the official golf course markers say.