Every time I root and install a custom rom gps lock slows down and is less accurate. Why is this true even when custom rom is based on stock rom? I would like to root again but I hate slow gps. IMO anything more than 10 sec is slow. All the fixes do nothing
I do not see how people put up with it
There are probably several things worth checking.
1) Is this something that happens only immediately after the ROM install, or persists indefinitely?
The best unassisted (meaning no aGPS) GPS module will take 60-180 seconds to acquire a first fix from a "cold start" condition, depending on satellite constellation configuration at that moment. It's not really possible to improve on that without differential GPS.
So, that "10 second fix" can really only happen in one way: by having a precise time estimate and also a good previous fix.
Before the advent of aGPS (Assisted GPS) in phones, handheld or marine GPS units would engage in a kind of trickery: they would always save the last fix acquired when shutting down, and then use that as an AP (Assumed Position) the next time they were powered up. A good AP guess can dramatically lower the time to a first fix if it happens to be close to the actual location.
And it just so happens that a lot of people experience that exact usage case: they shut off their GPS in the evening, sleep overnight, wake up and power up the GPS... just a few feet feet away from their last fix. Or consider a boat owner - they turn their GPS unit off when they return to port, and the next time they depart days or weeks later, they turn it back on right at the location of the previous fix (the harbor). Voila! A rapid 10-second fix!
Now enter aGPS; the cell network can give the phone very precise time and also a position to within a mile or so. Now it doesn't matter if you shut the device off, carry it cross country, and power it back on - if it is able to talk to the local carrier, it will have the precise time and a crude but decent estimate of position in a few milliseconds. That AP (Assumed Position) collapses the time required by the GPS to produce a first fix, and Voila! A ten-second fix!
(Remember that in the US, ALL cell phones - even dumb flip phones - have a GPS chip in them to comply with national 911 regulations; the Man always knows precisely where you are if you are in cell range... even when you "turn off your GPS")
So, the "10 second first fix" is a little bit illusory - it is not something the GPS unit is capable of by itself without assistance. Turn off your phone, fly to a different part of the globe, travel to a spot with no cell service, and turn it back on again... and it will take even longer than a cold start to get a first fix... because it starts up with a horrendously wrong "first guess" AP.
The first (Verizon) Android phone I had, I remember other owners claiming that GPS would not work at all when they were in Puerto Rico (roaming on another carrier)... and made the claim that the GPS chip was so heavily dependent on aGPS, that it simply could not ever get a fix without it. (The presumption was that the local carrier did not have any aGPS servers.) Later, I had the experience of using the same phone in wilderness conditions where I would keep the phone either off or in airplane mode to (save juice), and occasionally fire up the GPS to record a special location or two. Many times - whilst outdoors with a horizon-to-horizon view of the sky (with 6 or 7 birds up), that phone would take over a minute to lock. But it would eventually do so.
It is still possible that those folks were correct about the Puerto Rico thing - in my case my prior aGPS fix might have been 60 miles away, "in town"... but those other folks may have traveled closer to 1000 miles with their phones off. So my "last fix AP" guess was crude, but far less crude than theirs. (Either that or they were just impatient, and never waited the minute or two required for a "real" unassisted GPS fix in a brand-new location)
So I mention the above because a lot of stuff has to hang together to produce that "10 second fix"; an effort to decipher where the variability is coming from has to look at a large number of possibilities.
I don't know if this device (VSGN3) uses proprietary firmware device drivers ("blobs") for the GPS end of things - but if that were the case and a ROM was ported from a different carrier and the firmware blobs were not replaced correctly, that could account for something?
As for fix accuracy, remember that the GPS "Accuracy" is not the actual positional error - if you "knew what the error was", you could simply eliminate it by subtraction. At best it is a stochastic estimator based on signal strength estimates, positional diversity of satellite constellation, individual path delay estimates, etc.
Meaning: it is an estimator of system noise. You have to take a ton of measurements of noise to say anything meaningful about it, and a whole lot more than that to compare two noise distributions with any resolution.
So I would be careful about coming to the conclusion that the accuracy is worse - it is possible that you just happened to look when the constellation was poor.
This has happened to me in several phones. Fix 10 seconds before rooting. Several minutes 3 to 10 minutes after rooting and installing a custom rom, even if rom is based on original stock rom. Adding aGPS doesn't seem to help much. It has happened to me repeatedly. AOSP roms are the worst but even custom roms that are based on samsung rom have the issue. Its like vzw has some way to screw up gps once you root
Sent from my DROID RAZR HD using Tapatalk 2
Well, if you want to try to dig in and "get to the root of it", I think the area(s) you'll end up looking in revolve around how aGPS data is obtained & cached, how ROMs (read: Google location services) cache location data**, etc.
I just stepped outside with my stock-rooted VSGN3, which always seems to lock in about 8-12s under "normal" conditions. 15 birds in view. Then I:
- put the phone in Airplane mode (no cell, no WiFi**)
- using the GPS Status app (eclipsesim), clear the aGPS state.
- using app manager, force stop GPS Status, clear cache and data (of that app)
- turn off GPS
- start up GPS Status, accept EULA, go into settings and enable "display time to first fix"
- using app manager, force stop GPS Status, clear cache only (of that app)
- turn GPS on
- launch GPS Status
Result? Time to first fix = 215 seconds... With 15 birds in view!!!
If I repeat this process, but instead of waiting more than 60 seconds, I turn Airplane mode off... and within a few seconds the aGPS date goes to 0 hrs, and 8 seconds after that I get a first fix.
**I forgot to mention something in my first post. GPS Apps are clients of the Google Location services. Which means that a location "seed" can be obtained from Google's global location database even if you are using a carrier that provides no aGPS service.
How does this work? By co-opting billions of Android users to become participants in their vast geolocation data collection operation. Your neighbor or a stranger drives by your house with their always-connected Android phone on (& WiFi, GPS on), and it reports back to Google "hey, here I am at this precise lat/lon, and I see the following WiFi SSID/AP Mac Address"... namely - *your* WiFi router. Google then plops this unique device identifier into their geolocation database. Note that this sounds rather sinister, but the reality is that you were probably the first person to "drop a dime" on your WiFi router's lat/lon, with your own Android device. You only needed to authorize Location services once for that to happen.
Now a second Android user drives by. He has his GPS "turned off", and thinks "they don't know where I am, I have my GPS off". But he has unfortunately left WiFi on***. So his phone tells Google - via the (IP) mobile data network - "hey, I don't know where I am, but my WiFi sees the following WiFi SSID&AP Mac Address". And then Google replies, "oh, I know where you are, here is your position to within a few hundred feet". (And then the Google server says to itself, "heh, I also know what Google account owner hangs out there a lot - and that he's there right now. Heh.")
So I am not trying to dispute your observations; it's just that the location seeding data that actually creates an opportunity to get a "10-second fix" can originate from a variety of places, so your task of "getting to the bottom of it" (unless you are just here to complain) is a little bit complicated - you are going to have to spend some time digging if you want a "fix" (sorry, pun intended)
Good luck
*** Note one of the recent "features" of newer versions of Android is "give us permission to scan for WiFi networks even when you think WiFi is supposed to be off" - hmmm, why do you suppose that is?
Wow, great explanation. How did you gain this familiarity?
Related
Just received my HD and having trouble with GPS. I went straight into Google Maps and selected Use GPS but after about 3-4 minutes it says that no GPS was found. Going into External GPS settings and unticking 'Manage GPS automatically' results in Google Maps saying that no device was found straight away rather than the 3-4 minute wait.
Any ideas?
EDIT: going into Google Maps options > GPS Settings and setting it to Managed by Windows results in me getting a 'Seeking GPS satellites' message but it stays on 0.
Oppressa said:
Just received my HD and having trouble with GPS. I went straight into Google Maps and selected Use GPS but after about 3-4 minutes it says that no GPS was found. Going into External GPS settings and unticking 'Manage GPS automatically' results in Google Maps saying that no device was found straight away rather than the 3-4 minute wait.
Any ideas?
EDIT: going into Google Maps options > GPS Settings and setting it to Managed by Windows results in me getting a 'Seeking GPS satellites' message but it stays on 0.
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Click to collapse
ok now just be patient and go to a place where you can see the sky
getting a fix the first time takes some time. you can speed this up using the QuickGPS under programs. This downloads a satellite prediction map so the receiver can find satellites much quicker. Otherwise the receiver has to scan for bypassing satellites, which can take a few minutes to complete.
check next forum threat: http://forum.xda-developers.com/showthread.php?p=2923926&posted=1#post2923926
think I had the same problem as you have right now.
Thanks Gogem. I didn't want to but I gave a hard reset a try then went straight to Google Maps and still no luck. After saying it was looking for satellites for 3-4 minutes it said it couldn't connect to GPS, cancel or retry
Oppressa said:
Thanks Gogem. I didn't want to but I gave a hard reset a try then went straight to Google Maps and still no luck. After saying it was looking for satellites for 3-4 minutes it said it couldn't connect to GPS, cancel or retry
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as 6Fg8 mentioned you have to see the sky, inhouse or between tight buildings or in a canyon GPS isn't working. and.. this is by design of GPS (!) it can take up to 12 minutes to find the satellites! Technical background: all GPS infos streamed by the satellites have a very low power and data rate. QuickGPS can reduce this time. So be patient. Maybe a 3rd party app like "GPS Gate" (commercial, but 14 day trial available) may help.
Do you have another device to check the GPS receiving from your position, maybe your Blackstone is broken?
regards
ps: http://www.kowoma.de/gps/Signalaufbau.htm (sorry, German language)
Thanks. I just installed Co-Pilot 7 and checked the GPS signal. It must be because I'm inside. I can get 3 satellites on the receiver screen so it obviously is working. I'll just need to take it outside and see how I go then.
Oppressa said:
Thanks. I just installed Co-Pilot 7 and checked the GPS signal. It must be because I'm inside. I can get 3 satellites on the receiver screen so it obviously is working. I'll just need to take it outside and see how I go then.
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in theory you need 3 satellites (of total 31 active today) to get your x-y position on earth and (optional) a 4th satellite to get your altitude. each satellit is running in an orbit of 20,000 km. therefore your max height can be 20,000 km ;-)
in praxis you may see ca 6..8 satellites.
regards
bla3603 said:
in theory you need 3 satellites (of total 31 active today) to get your x-y position on earth and (optional) a 4th satellite to get your altitude. each satellit is running in an orbit of 20,000 km. therefore your max height can be 20,000 km ;-)
in praxis you may see ca 6..8 satellites.
regards
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yes in theory, but a lot of people mistake that as a hard requirement->when you pass, you must have a good reception for routing and such.
if you have seen the satellite graph, hte one with two or three con-centric circles, and satellite in or around those circles
you need at least two satellites in the inner most circle (45 degrees) to get a good lock, otherwise you woudl need more satellites to get a good lock.
the circles represent degrees from the verticle point of reference, ie think of you as the axis, and your feet is the origin.
Yeah in theory you need 3 points to triangulate. But I've never had a GPS give me my lat and long from just 3 satellites.
When I first opened my Polaris some time ago, it would not get a gps lock either. I had ordered an external gps antenna, so I hooked it up and got a lock real quick. Since then, I guess the gps chip in the phone knows what the gps signals taste like, so it always gets quick locks and works like a champ. In fact, it worked so well, I never used the external antenna again
LOL must be one of those new fangled learning chips you have there
JesseW said:
When I first opened my Polaris some time ago, it would not get a gps lock either. I had ordered an external gps antenna, so I hooked it up and got a lock real quick. Since then, I guess the gps chip in the phone knows what the gps signals taste like, so it always gets quick locks and works like a champ. In fact, it worked so well, I never used the external antenna again
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thats the reason why software like quickgps exists, it lets the gps chip smell where the satellites are. kind of odor transmission tool ...
GPS working fine... just no reception indoors that's all. Disappointing seeing as my girlfriend's new kaiser gets a complete signal in a room with 1 window.
Oppressa said:
GPS working fine... just no reception indoors that's all. Disappointing seeing as my girlfriend's new kaiser gets a complete signal in a room with 1 window.
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my touch HD gets signals indoors in three different houses. i was sitting quite far from the window, one of the building is my office -> thick concrete walls, etc. i know i should be cheering, but i'm very confuzzled... HOOOW IS IT WORKING with out a clear sight of the satellites?!?!
I was stunned (in a scary sort of way) just how accurate google maps got me based purely on mobile signal (before it tracked any satellites)...
It put the blue dot about 10feet to the left of where I was standing!
i dont know but i think gps is broken - i am loosing signal while driving in highway if i dont have hand up almost near roof - i made today almost 300km with avg speed 140km/h and touch hd gps *realyworking time* like 1/10 of whole trip. I realy think there must be some serios problem, because my co-driver with iphone google maps have totaly no problem
I have meant to write about this before. I have really never had a major issue with my GPS once I got it unlocked. I do generally get fairly fast locks. However I do travel with my job quite a bit. It seems that every time I get off the plane & into a rental car. It takes forever to get a lock. It has taken me sometime as long as 45 minutes. Has anyone else experienced this or have an explanation. I have tried resetting my phone several times, tweaking the registry, & using Clean Ram.
I used to see this sometime with my Dell navigation system for my X51v.
jadesse said:
I have meant to write about this before. I have really never had a major issue with my GPS once I got it unlocked. I do generally get fairly fast locks. However I do travel with my job quite a bit. It seems that every time I get off the plane & into a rental car. It takes forever to get a lock. It has taken me sometime as long as 45 minutes. Has anyone else experienced this or have an explanation. I have tried resetting my phone several times, tweaking the registry, & using Clean Ram.
I used to see this sometime with my Dell navigation system for my X51v.
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Honestly, some locations will give you more satellite lock-ons than others. Aside from that, you could use something like QuickGPS to get aGPS location based, so your device would connect faster... wild guess though
Use QuickGPS or or AstroLauncher, both work fairly nicely. With QuickGPS you have to update every week, but you get signal faster. With AstroLauncher there aren't any updates for satellite info, but it'll take a bit longer, around 5-10 minutes...
Again, long waiting times for locks is a general problem with the Vogue... I guess that is why the carriers decided to hide this feature (that and to try to stick you with data charges and propitiatory GPS software )
A number of people have experienced a long-standing Android bug on their Nexus One, that when you spend an extended period of time in an area with no signal, the phone never reconnects until a reboot. Even attempting to shut down cleanly or to go into and out of airplane mode results in Android crashing after a minute or so and rebooting that way.
It's hard to draw conclusions from my experience because the occurrence rate was so random (sometimes a couple of times in a single day, sometimes ten days between occurrences), but I installed Froyo Saturday evening and haven't experienced the "no service" bug since then. That's getting close to the MTBF for me over the last few months. The official ticket is still listed in "new" status (after almost a year!), but it's possible that some change in Froyo fixed it without the developer being aware of that particular ticket.
Has anyone who was experiencing the "no service" bug in 2.1 had it happen again since upgrading to Froyo? Now that I can do hands-free bluetooth dialing, that's the biggest remaining blemish on my Nexus One experience, so I'd be thrilled if the bug were, in fact, gone.
Just a little FYI, that is actually a common "bug" independent of Android. I sell cell phones for a living, and many phones, from BB's to WM, Nokia to Samsung, and everything in between has this "bug". Not all do, but I would say 90% of phones have this bug where if you leave coverage for an extended period, it doesn't re-connect when you move back in, and need to reboot. It is because phones are set up to stop searching for a network after X ammount of time without coverage, to prevent the battery drain of constantly searching. When you do go back into coverage, there are two ways to re-register... either reboot, or most phones have an option to manual search and register with a network. I know with my Nexus One this has only happened to me once, at my Dad's (his house is a deadzone for everyone), and all I did was do the manual search and was back up and running, didn't have to reboot.
The Nexus One version of this bug is unusually annoying, though: a manual search for networks turns up nothing (normally I have good signal strength whenever I step outside my house from both T-Mobile and AT&T, but neither shows up after the bug hits), and having the phone crash and spontaneously reboot if you enable airplane mode when the phone is in this state is pretty severe.
wmm said:
The Nexus One version of this bug is unusually annoying, though: a manual search for networks turns up nothing (normally I have good signal strength whenever I step outside my house from both T-Mobile and AT&T, but neither shows up after the bug hits), and having the phone crash and spontaneously reboot if you enable airplane mode when the phone is in this state is pretty severe.
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That is pretty severe, in that it reboots... but the "bug" of not getting signal back has nothing to do with strength or the N1 is all I am saying. I have at least 2 people a day come into my store with this issue, on all different handsets. Some can get it back just by manually searching (this is different from switching between airplane and back), others have to reboot.
I spent a few 1/2hr chunks today with my FRF50 Froyo'd N1 in a spot in the office that was guaranteed to cause this bug to show up. And every single time it's reacquired the network when I left. Take that with a grain of salt since the bug has been intermittent for me.
Now if only the headset and AVRCP music controls hadn't broken this would be phone heaven.
Yeah, I think it's improved for me with 2.2 as well. One thing that's handy though is an Airplane Mode widget, as cycling the antenna with that usually worked for me before Froyo.
this "bug" drove me crazy! It would tend to happen to me at least once a day. I am scared to say this, but it hasn't happened one single time since updating to "unofficial froyo"
Well, good news all around! I'm not quite ready to declare the bug dead, because I've been disappointed a number of times after tweaking something and having the bug lurk quietly for a number of days, only to pop up again after I had decided it was gone, but it's certainly looking encouraging. Thanks for all the responses. Keep us updated.
I've had the same bug issues, and usually at home when it happens. This radio seems determined to reacquire no matter what.
As for the AVRCP comment, my N1 a la FroYo is working great with my BT3030 stereo Bluetooth receiver. I use the controls all the time.
I think i am having somewhat of a unique problem with this. My "use network to determine location" setting isnt working. When i first turn on or reboot the phone it will find my location as usual. But as soon as i have turned the GPS on this setting will no longer work. Once i turn GPS off it no longer uses the cell towers to determine my location. In fact, when i turn GPS off, my location on google maps jumps back to where i was before i turned GPS on. So when i did this at home, it told me i was still near my work, which is 10 miles away. Anyone else have this issue? It is very frustrating when using an app like sherpa or yelp because it is lot looking for stuff anywhere near where i am.
odd problem. i've read similar things about the gps. Maybe i'm just close to the sattelites, but i get great GPS. In fact, this is the best GPS i've ever gotten from a phone. I've had a ton of smartphones with GPS including blackberry, iphone, iphone 3g, Htc Hero, HTC EVO, and now this Vibrant.
This is the first time, i've had a phone GPS that stayed in the lane the entire way i drove home. Plus it was always right on the spot without delay. The only grievance was it took about a minute to sync up. Reminded me of the old TOMTOM devices and their 1 minute syncs. But once it got going, it was spot on.
This is not a GPS issue. It does take me a little bit to connect to GPS, but i am mainly concerned with being able to use the network to determine my location. This function uses less battery than GPS but still works for things like sherpa and Yelp.
Wow...I wsa hoping this was going to be a hot issue that other people were experiencing. This makes me think i should exchange my phone because i have some sort of defect. Please, any opinions...
After applying the GPS fix I am having an odd issue. When I fist launch google maps it shows me in some small rural village in China. Once the GPS gets a fix it goes to where I am really am. This would not be a big deal except when I take pictures it Geotags the picture as being in this Chinese village which is kind of a pain. Also it screws up my weather widgets sometimes. Any ideas? I was thinking maybe it has to do with the server it is using to pull down the GPS data, but not sure.
I am having a similar issue, but not quite as drastic. Mine just simply shows me being the last place i was before GPS was turned on. Like right now, without GPS connected but using the towers to figure out my location, it shows me at the place i at lunch, about 3 miles away, rather than at work. Its VERY frustrating.
I'm having the same problem. My GPS shows me in a neighboring city that is 50 miles away, every time.
The best way to test this is to load the 'Maps' live wallpaper. It happens every time. Also, booting up the 'Maps' application will throw me into the other city for at least five minutes, before it realizes that the data is not correct.
It's a new "google fortune" feature. It's telling you you need to travel the world.
Same problem here, however, I was thinking it had more to do with the "Use Wireless Networks" not updating my location.
-If I have gps turned off and wireless network location on. My location doesn't update at all until I reboot the phone (although Latitude shows it as being updated within the last few minutes, even though it shows me somewhere I haven't been in hours and is 50miles away.)
-If I turn gps on, it will then get a fix and properly update my location.
I did apply the GPS fix.
lol mine switches between seattle and SPAIN! wtf.
I think it has to do something with the way samsung implements the gps receiver..a friend had a sammie moment..she would be right next to me..nyc...but her gps would say shes in havana, cuba..on good days..some place in estonia..lol...and now i see the issues being replicated here...i blame samsung...my old trusty g1 locks a signal and is very accurate within a min or 2..
Thanks for the info, sync3. That's starting to become my thought as well.
What a shame. I hope an official statement is released, either way.
chastbi said:
Same problem here, however, I was thinking it had more to do with the "Use Wireless Networks" not updating my location.
-If I have gps turned off and wireless network location on. My location doesn't update at all until I reboot the phone (although Latitude shows it as being updated within the last few minutes, even though it shows me somewhere I haven't been in hours and is 50miles away.)
-If I turn gps on, it will then get a fix and properly update my location.
I did apply the GPS fix.
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Click to collapse
This is the EXACT problem I am having. I dont know how to get it to update my location.
I have the same issue. I also had applied the GPS fix... I've tried reverting to stock settings, tried enabling skyhook and tried a few other things.
The only way I've been able to properly get my location is to turn off the network assist and tell the GPS to operate in standalone mode. It takes a heck of a lot longer for a fix, but it's accurate if it does get a lock. Doesn't work so well indoors though.
Who the heck were the field testers for this device? its full of more bugs than an entymologist's labratory.
Clear your GPS data
heygrl said:
Clear your GPS data
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That was one of the first things I tried. It didn't help.
My main concern is that this is unrelated to the GPS software issue and that this is actually a hardware issue. Does anyone agree or disagree with this?
pearlblues said:
My main concern is that this is unrelated to the GPS software issue and that this is actually a hardware issue. Does anyone agree or disagree with this?
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I agree this is hardware related because others have reported exchanging their phones rids them of the GPS issues.. :-/
I work in Houston and sometimes while at work GPS says I'm in Pawcatuck, CT.
The question is when not using gps what function of the phone updates your location? Could it be a network issue? How do you force it to retrieve tower data that marks your location?
Sent from my SGH-T959 using XDA App
Well, i exchanged my phone last night because of this issue and the new one is doing the same thing. So either this is a problem inherent to this model (hopefully the software not telling the phone to refresh tower data) that can be fixed with an update or i am extremely unlucky.
pearlblues said:
Well, i exchanged my phone last night because of this issue and the new one is doing the same thing. So either this is a problem inherent to this model (hopefully the software not telling the phone to refresh tower data) that can be fixed with an update or i am extremely unlucky.
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Just had my 3rd call with TMobile- she now assured me that this is a software issue (which i made her mark in my account incase it winds up being hardware later) and that all phones with software # T959UVJFD have it. She said tmobile is working with samsung to fix. I told her all Galaxy S series, domestic and international, have GPS issue and samsung has yet to fix any. She said well that is something you need to consider.
blink55184 said:
Just had my 3rd call with TMobile- she now assured me that this is a software issue (which i made her mark in my account incase it winds up being hardware later) and that all phones with software # T959UVJFD have it. She said tmobile is working with samsung to fix. I told her all Galaxy S series, domestic and international, have GPS issue and samsung has yet to fix any. She said well that is something you need to consider.
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Wow, very helpful information. How they get this fix released ASAP.