Database Develop

GPS position and bad position fix

I have had GPS receivers previously as well as used some, both normal consumer as well as aviation grade GPS systems. Now I have the Kaiser/TyTN II and I am impressed with how sensitive it is! For not losing signal or dropping position I am amazed, good stuff!
BUT ... since it uses so much battery when the GPS is running, I sometimes turn it of for a while, then on later on again. Especially when moving a lot while being turned off (flying or driving), turning it back on can sometimes give problems getting a new fix! Sometimes it gets a fix quickly, but it is hundreds or thousands of miles off. I know it is complicated 3D math for a GPS to aquire its position, and I know it is possible to get a false lock, but the GPS receivers I have tried and had previously never accepted a bad fix.
The unit knows where the satellites are supposed to be, given the time and approximate position, so that is what it assumes. But when it has been off, and then on again and only moved some hundred miles, it can get this false position fix that it cannot get out of easily. If I turn it off again and wait until none of the previous satellites are in view (flying for another hour for instance), it finally realizes it has to start over with a new fix. Older GPS units I used/had often had an option of making a cold start fix (search the sky, autosearch or other names for basically the same thing). It is also sometimes possible to specify or change the last "known" position of the GPS to make it easier for it to get a new fix again. The latter requires that you either can find your rough position in a map or you know a rough lat/lon position.
So, two questions:
1) How do I break a bad fix, tell the unit it is on a wrong path - do a renewed search the sky?
2) How can I change the "previous GPS position" so the GPS unit is forced to assume another position?
I have some GPS applications where you can change the last know position, but it only seems to stay in the program, it is not fed back into the GPS receiver.

No comments here? Must be others with the same problem. Even the oldest, most basic GPS units had an option to enter position manually, or to enforce a new search from scratch. There must at least be some kind of reset function! (NOT hard reset, thanks!)

LGB said:
No comments here? Must be others with the same problem. Even the oldest, most basic GPS units had an option to enter position manually, or to enforce a new search from scratch. There must at least be some kind of reset function! (NOT hard reset, thanks!)
Click to expand...
Click to collapse
I tried google maps and discovered that my actual position was off by some 50 meters from where I actually was. Then I also discovered that in the area I was, if you superimposed the roads on top of the satellite image in Google maps, it was also set off, by about 10 meters only.
Ever since I tried Google maps, my GPS fixes correctly and updates data all the time, but with some programs speed remains 0 and direction remains north even if I move around. After re-flashing the original rom everything is back to normal. Do you know why this happened?

I have got the same problem.
Once after using TrackMe and once after getting my position in Virtual Earth Mobile.
Both times i have used the gps only for a short while and then closed it. On the next start the position has been several hundreds of kilometers off and the speed shows several hundreds kph although I stand still.
Both times the gps has not been ok until the next day.
I have tried to soft reset and also updated the Quick GPS with no result.
I found this thread Kaiser GPS positioning problems which looks a lot like the same.
I have been using the GPS a lot more frequently recently and at first I thought it was these two apps, but now it seem more general. Before I used TomTom on a few occasions with no problem, but then the GPS was on for a longer period.
Anyone else?

GPS Tuner: No compass?

I have installed GPS Tuner 5.4f (2 week trial) on the Diamond and it works with built-in GPS, so far.
But the Diamond allways shows focused to north. On compass screen I can move and rotate the Diamond on all directions without any reaction.
So ist there a problem with GPS Tuner or can't the Diamond - a GPS handy - handle the compass?
Thx & regards,
Purzel

The compass is not moving because static navigation is enabled, so unless your moving at least 3mph the compass will not move. Same with any GPS navigation software.
At the moment nobody knows how to turn off static navigation, it's a really stupid feature.
Try driving or running then the compass will move

Radeon123 said:
Tso unless your moving at least 3mph the compass will not move.
Click to expand...
Click to collapse
You are kidding me, right? *lol*
So I have to run around the trees in the wood next weekend to say my family where to go at next...
Regards,
Purzel

Radeon123 said:
The compass is not moving because static navigation is enabled, so unless your moving at least 3mph the compass will not move. Same with any GPS navigation software.
At the moment nobody knows how to turn off static navigation, it's a really stupid feature.
Try driving or running then the compass will move
Click to expand...
Click to collapse
So there actually is a digital compass inside?
Edit: sorry, didn't know what static navigation means. Now I do. Unfortunate, because I really wished there was a digital compass inside .

How does the phone know which way it is pointing? You have to move so it can figure it out. GPS systems that point north when static have a built in electronic compass. These phones don't. You can see this when people set of following a gps arrow and they almost walk in a circle before they head off in the right direction.
By the way, Memory Map is an awsome bit of sofware for navigating using the phone. I use it as a back up to my paper map and compass whilst out and about.

How did you get the GPS to work, tried the auto search for the GPS device and GPS Tuner says that he can´t find any device. Manually set to COM4 no luck either.

You'll find that if you walk about five or so metres it will begin to register a speed and accurate heading... does in all my GPS apps. I use Pathaway and Fugawi for on foot navigation and it's a great alternative to paper map and compass.
Without an actual magnetic compass on board, there is no such thing as a GPS receiver capable of showing accurate heading without meaningful movement. The static navigation feature is really very useful as it stops the thing dancing all over the place when you're stood still... below this movement threshold, the small scale erratic nature of the outputs at or near rest are pretty much unusable.

Inaccuracy of GPS

Well i have a question.
When i use TomTom or IGO the position on the screen is always about 50 meters off to where I actually am.
So since IGO & TomTom Both have the same behaviour i guess i should look at the GPS module.
My old S730 was always spot on... when i looked at the screen and saw a turn on the left, there actually was a turn to the left.
Anybody knows how this can be solved ?

My TD2 does not have this problem, perhaps there is an issue with your particular phone?

I thoght about it before and found out that it was not inaccuracy but the delay GPS chip needs to calculate your position. Do one test. Some time when you stop at a red light and you know you've waited for about 5 secs, check your position then. I believe it will be accurate then.
I noticed that some GPS's try to calculate your current position based on direction and speed you had few seconds ago. I found out about it one time when I waited at the red light in a long tunnel. Obviously there was no signal there, but when I stopped, GPS kept on showing that I was moving about 40MPH for several seconds before it finally showed lost signal message.
Some GPS's do calculate your position ahead of time and some don't.

Maybe it was because i had assisted GPS turned on...
If you do a search on AGPS LAG (ANY HTCPRODUCT WITH AGPS) then you will see enough posts that speciffically deals with this problem...
My old phone is SPOT ON with TT and my new 2 times faster phone is less accurate, and in a street with lots of turns, take a-lefts etc it's quite important to rely on the machine. And when the machine says turn left on the next corner, is that left the one i am currently at or the one 20 meters ahead from where i am now....
It should be just as with my old phone spot on

Well disabeling AGPS definitely works...
I am now about 20 meters behind all the time. This seems acceptable although I keep finding it strange that my older phone was way more accurate.....

you mean disable QuickGPS or disable AGPS in Advanced Config??

It is definitely a lag issue, not a precision issue: my TD2 internal GPS is at least as accurate as my Qstarz bluetooth GPS logger, and this one has a dedicated large antenna and good GPS chipset. TD2 sensitivity is also comparable, maybe even better inside building, and the time before locking a signal from coldstart is also comparable or better...
BUT there is a lag of maybe 30 m around 50 km/h in my car, and it is is indeed quite noticeable for driving directions...No big deal for me, as I do not rely on voice instruction but always have a quick peak at the screen (I was bitten by ambiguous instruction often enough in the past with other GPS system to have developped this quick peak habit ;-) )..but this lag is indeed anoying...
I'd like to try the TD2 using the external GPS through bluetooth, if I find time to do it this WE I will post my conclusions...

well0549 said:
Well i have a question.
When i use TomTom or IGO the position on the screen is always about 50 meters off to where I actually am.
So since IGO & TomTom Both have the same behaviour i guess i should look at the GPS module.
My old S730 was always spot on... when i looked at the screen and saw a turn on the left, there actually was a turn to the left.
Anybody knows how this can be solved ?
Click to expand...
Click to collapse
I use to have the same problem as you, so, I've tried the tweak referred in this post http://forum.xda-developers.com/showthread.php?t=514912 and it did the trick for me.
I use iGo8 and NDrive and the accuracy improved a lot, it's almost spot on, no matter what speed I'm driving.
Regards,

I was in my mates Audi TT the other day. He has the built in GPS in the dash board. I noticed there was as much lag as you see on an HTC device.
Also was in a car a few months asgo with someone who had a stand alone TomTom device and that too had lag.
Unless you're paying thousands of Dollars for millitary grade navigation equipment, i wouldn't spare the lag issue another thought.

Not long now ...
There's a bigger lag comming if the media are to be believed (and based on everything that comes from the tele, radio and newspapers these days - there're probably not - they can't even get the weather right)
http://news.sky.com/skynews/Home/Technology/GPS-Network-Could-Fail-Next-Year-Leaving-Sat-Nav-Useless-US-Government-Accountability-Office-Warns/Article/200905315284843?lpos=Technology_Carousel_Region_4&lid=ARTICLE_15284843_GPS_Network_Could_Fail_Next_Year_Leaving_Sat_Nav_Useless%2C_US_Government_Accountability_Office_Warns

"
Unless you're paying thousands of Dollars for millitary grade navigation equipment, i wouldn't spare the lag issue another thought."
Diamond1 paid £150 was spot on. No Lag. The speed indicator on tomtom was very accurate, not like on the diamond2 where it takes over 2 seconds to show a speed change. I am surprised that not many people have noticed the slow and inaccurate GPS performance of the D2.

[Q] Digital Compass

Hi,
It really seems that the G1 has a digital compass, but I couldn't see it documented and doesn't seem to be part of the specifications.
However I tested it a few times with GPS Toolbox and it seems to accurate to be based on GPS (also because I think GPS one would actually be "heading" and only generated if moving).
Anyone has any thought ?
Nick

Of course the G1 has a compass. Yeah GPS doesn't know anything about orientation, only 3d position. Along with the accelerometers the phone can know it's exact position and oriention.
Fire up google maps and look, your position marker is a compass arrow. All it's search results etc all show orientation arrow also. Plus if you tap the "my location" circle icon a second time, maps itself goes into compass mode (as can street view). The compass is a base standard of android, just don't trust it if you have a charge cable plugged in

Thank you.
I had a look again at gsmarena and it says that it has a digital compass, which at the time the phone came out was not yet a standard feature (even if GPS was present)
I was SO sure that I had researched it some time ago and it didn't say anything about it .. my bad.
Thanks !

[Q] S3 Mini - gps inaccurate while running

Hi, I purchased S3 mini around december 2012, one of the main reasons why I bought it was the gps/glonass-feature, since I figured it would provide me with more accurate tracking while running. Previously I had used a Samsung Galaxy Gio phone for running, and with rooting and a gpsfix (changed the server) it provided accurate gps in long half-marathon runs and so forth. The issue with that phone was that the battery life was terrible.
Now, the S3 mini is brilliant in battery consumption, but the gps accuracy has been horrid. It locks a satellite within seconds, several satellites are in use immediately. So, nothing to complain there. However, it is almost one street off, throughout my run. It tracks usually 1-2 kilometers less distance than the Gio, which manages to stay on the road I'm running on perfectly. If I'm to believe the S3 mini, I frequently run in water and through people's backyards...
Now, I have attempted the usual tricks, cleared agps, updated it before runs, calibrated the compass with GPS status indoors and outdoors. But nothing seems to work. Many times the gps will track perfectly when I'm headed, let's say northwards for several kilometers, but then when I turn to go west-east or southwards (for example) the gps accuracy goes off. I'm hoping this is an issue that could be easily fixed, since it's a shame that such a fabulous phone like the s3 mini fails to be a good running partner.
My S3 mini is not rooted, most of the gps fixes only fix satellite locking. My issue is inaccuracy, and yes, many people think it's normal, but having had perfect tracking with an entry-level smart phone like Samsung Galaxy Gio, I fail to understand why my S3 Mini does not excel in this area.
What else should/could I try? or just use my gio while running and hope it doesn't run out of battery in 1,5 hours.

I have also noticed the inaccurate gps of the s3 mini. After some positional testing I have decided that the gps is just not V good on this phone including being mounted on shoulder.
I also have an issue where gps locks up and freezes when the phone sleeps. I have yet to overcome this. I'm hoping it's a kernel issue brought about by flashing.
After years of smartphone soul searching, I now use a Garmin 405cx for sports, etrex10 for work and hiking, and a tomtom for sat navigation. I only now rely on the shoddy gps for View ranger Os mapping on the phone. Based on its performance I've started purchasing paper maps and now use those to navigate while walking and hiking.
This makes me very sad. I love android and like the s3mini. However yesterday I contemplated throwing it across lane 3 of the M20.
Sent from my GT-I8190 using Tapatalk 2

Hi, I have a same problem with my new Samsung Galaxy S3 mini and Sports Tracker. And many other reporting this problem. Sports Tracker works fine with my ZTE Blade. The first I thought that the fault is in bad GPS module in my phone. But the GPS work fine with Navi software. I realized that in Navi software the phone screen is always on and with Sport Tracker go in stanby. And when the screen go in standby the gps stop working. And when the signal is repeatedly interrupted then for a long time does not want to connect. Solution is that you in Sport Tracker settigs set Screen backlight to Always on. Now the problem is that the random clicking Stop suspended yor current workout. I do not know if fault is with Jelly Bean ROM or with Samsung Galaxy phones. Later I again tested navi app IGO Primo and if I turned off the screen GPS also go on off.
Phone screen always ON is also not an ideal solution. Because the signal is still losing, but every once for a second.
I tried various apps: GPS Status (settings: Background behavior/The app will keep the GPS running even the device screen is turned off.
But it does not work).Tracker Booster, Keep My GPS Alive, but without success
Is there any solution for this?

I've got the same problem while using GPS in a running application (like runkeeper, runtastic or endomondo).
I know this is an old thread, but I want to ask if anyone has found a solution for this problem.
I would be very thankful!

I have the exact same problem. After two months of GPS hell with my SII I got a new SIII mini. Initial GPS lock and detection goes really quick (22 satellites). If I do a quick turn in running it seems that it tracks a bit of until the end. It may be 100 meter or 200 meter on a 10 kilometer (and people indeed say it's normal, but with my SII it was perfect)
Could it be processor related? I run with a bluetooth heart rate sensor, google music, running app, etc. I tend to believe if I switch of 3G that it goes better.
Any other suggestions on this?

I have basically come to the conclusion that the GPS on this phone is ****, primarily due to the OS sleeping it. Which is a battery saving strategy. We do have very good battery life on these devices.
The GPS doesn't have any issues if an app is using it, like (Viewranger recording a track). This prevents the OS sleeping it. However accuracy of the GPS on SGS3M is poor. But really if you after doing serious tasks that require even a hint of accuracy then purchasing a dedicated device is the way forward. If you run try the Garmin range of fitness devices. If it's work try a hiking GPS I use a etrex 20 for assisting in surveying trees. Recording my movements across a site and the locations of any trees with works associated.
I think the phone manufacturer decided that the accuracy issue was not a concern as many navigation apps would snap the users location to roads and such.
Don't hold out for any solution. I can say the only thing to ensure is the latest firmware. I have the latest which isn't available on the "BTU" location code. However the German firmware works fine with my UK device. Check the Dev thread for latest stock rom, (pretty rooted).
Sent from my Nexus 7 using Tapatalk 2

gaze eademno
ninjalandpirate said:
I have basically come to the conclusion that the GPS on this phone is ****, primarily due to the OS sleeping it. Which is a battery saving strategy. We do have very good battery life on these devices.
Click to expand...
Click to collapse
I don't know what to think from it. If I track a car drive with it (using Endomondo), it uses a perfect track to road tracking.
Also initial running tracking using Endomondo is fine. It seems that a sudden change in direction (eg a sudden change from south to nord) let's down the accuracy. It's strange because the device has a very good satelite detection and fast lock.

NicolasBE said:
I don't know what to think from it. If I track a car drive with it (using Endomondo), it uses a perfect track to road tracking.
Also initial running tracking using Endomondo is fine. It seems that a sudden change in direction (eg a sudden change from south to nord) let's down the accuracy. It's strange because the device has a very good satelite detection and fast lock.
Click to expand...
Click to collapse
This morning I had a spectacular improvement.
What has changed:
I installed the latest 4.1.2 official build from sammobile.com
I ran without 3G location services. (pure on GPS)
I also switched the device from being upside down on my left arm, to being straight on my right arm.
Possible something that has nothing to do with it: my work e-mail policy was not yet enabled on the device.
I also ran a slightly other route (but there was still a sharp turn halfway involved), and the signal corrected itself perfectly.
My bluetooth heart rate was enabled, 3G was enabled and google play music was enabled.
So the thing I'm eager to try is: enabling location services again, and doing the route that caused trouble again.
But to be honest ... I think it's the new 4.1.2 build that solved it.

My gf's phone has XXAMG1 build and it has exactly this same issue. GPS shuts down a couple of minutes from start.

Recently I found out that my GPS becomes inaccurate when I enter into the forest. I use it mostly for navigation while mountain biking. The position defers after 10 to 20 minutes for 200 to 400 metres. The position error direction is almost every time in the direction of departure point that means that GPS position stays behind me. When I check GPS reception with GPS test, there are always 5 to 12 satellites in use with estimated error up to 5 metres. The interest thing is that if I switch GPS off and then again ON, the new first fix is very accurate. After that, if I continue cycling, the position becomes inaccurate again. I have tried different programs (sports tracker, view ranger, orux maps, Google maps) with same results.
Any suggestions very welcome.

Same issue here (example included)
Same issue here. S3 Mini and Endomondo. Tracks start to differ after a certain amount of time (refer to attached JPG)
Chatted with Samsung about this issue and they told me that this is caused by the fact that all Galaxy phones have AGPS, where an internet connection is neccessary for the GPS to work. But I am not sure that this is the problem...
Samsung told me that I am the only person indicating this is a problem so it's probably my phone. Perhaps good to file an official support request at Samsung?

My few thoughts on this...
On stock rom everything was working well. except for the rom itself.
On maclaw cm 10.1. gps worked well until after an hour or so of use for tracking. then gps decided that I'm cca 100 meters away from spot where I was standing. it just translated my position and stayed translated the whole time until I turned gps on/off.
On Stock i8190XXAMJ3 gps was amazing, it was locking onto satelittes even inside the house, but it had the same issue like cm10.1 rom.
Now I'm on S5style_i8190XXANA2_v1 and for now gps look good, didn't have any issue, hope it will stay like this.
just to say, I've played with gps.conf, with various apps like gps status, gps test, resetting agps data, trying different apps for tracking and nothing worked. after a while, gps simply translates my position and stays like that.

to reply to myself...
for some reason every stock rom I flashed with cwm apparently didn't flash baseband with it (or something went wrong), so phone was showing original baseband version. then I flashed baseband ANA2 separately and now gps shows no problems stated in previous post.

I've had the same problem on my S3 mini. I'd tried a few apps to track my sport activities before I've found working one - Navime Sport Tracker. Since then I've been using it and faced no problems with GPS and tracking. Unfortunately app only works in Poland. So you may ask why I'm writing about this. I do so because I reckon that problem sometimes lies in a tracking app itself. E.g. in the same place where Navime was detecting 7-13 satellites Endomondo (with identical GPS settings) managed to find 1 or 2. That's how I solved my problem. And one more thing - I use stock-Samsung Android 4.1.2 (newest).
My usual GPS config:
- GPS is ON (obviously)
- using wireless network to fix GPS is OFF (option on the top)
- GPS data available for Google services is ON (option on the bottom)
- data connection is ON
Proof:
navime.pl/trasa/348283/Katowice-Pszczyna+17.04.2014

Hi pcm266
I know this is a reply to a post a year old, but this is the closest description of the problem I continue to experience. Perhaps you and others are still looking for a solution.
This is NOT simply a matter of poor connections due to loose screws. I tried a month ago tightening screws, checked every setting but the problem persists. Loosened then tightened screws again yesterday. Today I ran with both my S3mini and my old Samsung GIO. The GIO recorded perfectly!
Your sentence "Many times the gps will track perfectly when I'm headed, let's say northwards for several kilometers, but then when I turn to go west-east or southwards (for example) the gps accuracy goes off. " is pretty well what I see happening.
What is puzzling is that S3mini worked perfectly in a race on 29 March. ??? Have not been able to repeat that.
Tightening screws is certainly not helping me. I am sure that this is a software error. There is a consistency in the type of error that is not is the type of error I would expect from intermittent connections.
Another strange thing is that the S3mini tracking is pretty good when travelling in a car. It is when I ran - which is of course much slower than a car - that the tracking is worse. Something to do with collecting too much data and doing some sort of averaging????
My son runs with an S3. Never had a single tracking problem.
A tip re the GIO battery: The Lithium-hydride batteries in laptop battery packs have the same charging characteristics as the batteries in the Samsung phones. I simply soldered wires from the contact points in the phone to a battery taken from an old laptop pack. (Usually when these battery packs fail, most of the individual cells are still good. I use them in all sorts of applications. ) The battery is fastened to the back of the Gio with duct tape. The phone no longer has a simcard in it, so I keep it on airplane mode. The battery stays charged for days!

Guys, I've never experienced this GPS problem. My S3 Mini has completely accurate readings both in car and while walking. You can try and update your phone to a newer firmware version if it's still on a firmware from a year ago. Don't know what else to suggest, God bless my S3 Mini for not having this problem, 'cause I use GPS frequently

Hello, I have the same problem with inaccurate gps after some time. Is there any solution. I use this phone only for running, so for me it is not a problem to flash another rom. I hope someone can give me a solution or a rom that works while running.