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Something I noticed about the GPS.

Took a 300 mile each way car trip over the last 2 days. I had my Captivate and 4 year old Tom Tom XLS with 9 month old update. We didnt need the Tom Tom until about 10 miles from our destination. Turned it on at the same time as opening Navigation on the Captivate. It took around 5 minutes for them to get a satellite lock. The interesting thing was they locked at EXACTLY the same time.
Now, the Tom Tom (TT) usually locks in 30 seconds or less if I turn it on near home. If I'm over say 100 miles from home it takes several minutes to lock on. I had heard this is due to the TT looking for the same satellites or number of satellites as when it was last locked on.
So that said, when we were leaving, I turned on the TT and Captivate and did the same thing. TT locked in about 30 seconds, Captivate in about 5 minutes. When we were 100 miles from home I turned off the TT and Captivate. Turned on again at home and they both took exactly the same time to lock on again - about 5 minutes.
I noticed a similar lag with my Tilt 1 if I didnt download the quicksat updates. If they were installed, the thing locked on very quick.
So could the Captivate have no historical data of the last lock and thus is always trying to track and locate satellites that are not visible, gives up then locks onto new ones?
Am I smoking something?

With everyone complaining about the gps, I have had absolutely no trouble with it. Being very inaccurate with the famous blue circle around it is only when it does not have a CLEAR view of the sky. I bought a holder that sticks on the windshield and it locks on in about 2-4 minutes, and it deadly accurate from there. I have the cheap tom tom and the captivate is just as accurate as the TT. Actually locks on faster than my TT if Im moving. I've tested it a lot to see if I can have trouble, but unless I block its view.... I have 100% reliable operation out if it.

klloyd said:
With everyone complaining about the gps, I have had absolutely no trouble with it. Being very inaccurate with the famous blue circle around it is only when it does not have a CLEAR view of the sky. I bought a holder that sticks on the windshield and it locks on in about 2-4 minutes, and it deadly accurate from there. I have the cheap tom tom and the captivate is just as accurate as the TT. Actually locks on faster than my TT if Im moving. I've tested it a lot to see if I can have trouble, but unless I block its view.... I have 100% reliable operation out if it.
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2-4 minutes sucks bad for locking and needing a 100% clear view of the sky is also bogus. What happens if you don't live in the flat rectangle known as Kansas? The GPS on these flat out sucks. I have a 10+ year old "cobra" handheld GPS that locks faster and holds lock / is more accurate.

I live in that flat rectangle, and it still would get lost.

OP
I think you are on the right track. In addition to othe issues with the gps, such as incorrectly intrpreting the time zone and having GMT 5 hours off, regardless what other people say, it seems to be starting in"cold" mode always, whic means it needs to download all the positional data first, determine the satellites positions and the attempt to get a fix. This takes about 5 min in any gps, simply because the transmission rate of the gps satellites is very low.
Your tomtom attempts to take a shortcut assuming it's not too far from where it was turned off last time. If true, it can get a fix in 20 secs or less, if false, it would take 5 min.
Sent from my SGH-T959 using XDA App

Mine always locks in within 20 seconds, whether I am moving on stationary, hot start or cold start. I've even tried turning it on 100s of miles from my usual location and still locks and holds while driving to 32ft accuracy. I am already on my second captivate, the first one liked to turn off randomly. The first one didn't have a gps problem either.
I did do the supl.google fix to both though. They were slow with factory settings.
Under LbsTestMode do you have it set to HotStart and MS Based?
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jmgelba said:
Took a 300 mile each way car trip over the last 2 days. I had my Captivate and 4 year old Tom Tom XLS with 9 month old update. We didnt need the Tom Tom until about 10 miles from our destination. Turned it on at the same time as opening Navigation on the Captivate. It took around 5 minutes for them to get a satellite lock. The interesting thing was they locked at EXACTLY the same time.
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Click to collapse
I did notice the same thing when I was on a trip in Wyoming two weeks ago. I hadn't turned on either GPS (in this case the car one was a Garmin) and when I did both locked at the exact same time (probably after about 3-4 minutes after turning them on). It was quite surprising because I thought the Garmin would go much faster than my Captivate, but this was not the case.

I was extremely lost last night in the city with buildings all over on a cloudy night. Gps found me and directed me in about 1 min coming from a car garage .
I've noticed it locks faster if you back out of Google maps while its finding your location and go back in. It seems to get a lock quicker. Same goes for navigation, I enter a destination and hit navigate, if it don't find a lock within say 10 seconds like it usually does for me ill hit back once and then navigate again. Then it usually finds a lock fast almost instantly ..
I do get the blue circle while navigating sometimes , but it moves along perfectly . Ill even just use google maps without the navigation and watch myself move on the map nicely...
I usually get from 4 to 7 satellites out of 12 or so.
Works for me, if it can be better cool, but its done me well so far can't complain too much.

I tried using it last night. Not sure how many satellites it locked on to, but it did give me the accurate to 5 meters message in Maps.
That said, it was ever so slightly off (probably 6 or 7 meters instead of 5) and my compass is blown. Even after calibrating it, its still a few degrees off (15 - 20 maybe?).

my GPS testing: OK for me. My opinion...

I bought my first Captivate at the very beginning of August. I wanted the GPS to work, so I could use it instead of a separate GPS unit sometimes. After about 5 days the GPS was really struggling to lock. I put it outside under the open sky for 5 minutes with GPS Test, and it saw lots of satellites but used zero. I reset the phone and poof, it worked properly again. That seemed like a strange bug to me. I heard an update was coming by the end of September, but that was going to be outside my 30 days, so I returned my Captivate to Best Buy and got my $230 back, no problems.
Sept 7, I bought a new Captivate, now only $150 at Best Buy. This one worked fine and the GPS never completely failed like the first one did. But I didn't test much as I waited for the update. September 22 I forced the update on my normal unrooted captivate, and it went fine. I did some testing and the GPS seemed to track OK and lock in a reasonable time. Now its a week later and it still seems good.
Here are a couple comments.
First a note on my GPS experience. I own 3 GPS units besides the Captivate, and older MIO C230, a Garmin eTrex Centure HC, and SPOT 2 GPS Messenger. I also have extensive experience with a Garmin Nuvi 1390T. I ride a dirt bike in the desert and have used tracks to navigate extensively.
- Time to get satellite lock. The Captivate does often take a while to lock on the satellites. But so do all my other GPS devices. Sometimes they lock quickly, but often they can take a minute or more. This is related to whether they have stored data on where they are, and thus know where to look for the satellites. At any rate I don't always get a quick lock on the Captivate, but it has never failed to get a lock under a clear sky if I give it up a minute or two. 10m resolution is typical once locked under a unobstructed sky. For those having trouble with this: Are you giving the Captivate a clear view of the sky and a couple minutes? Yes, sometimes GPS's lock indoors and really quickly. But in my experience this isn't always true. What I'm saying is the Captivate works similarly to the other GPS's I use. Sometimes fast, sometimes slow. But it is always locking under a clear unobstructed sky within a couple minutes.
- Google maps. After it locks, the captivate shows my location on the map well. As I said above, sometimes lock takes a minute or more. And it requires a clear view of the sky most of the time.
- Track quality. I tested with "My Tracks". I run around town on a scooter every day, so its easy to turn on the tracker and and see what happens. I put the Captivate in my pocket on my thigh, back side facing the sky. The only thing obscuring its view is my body. Basically, it seems to work fine. It certainly works as well as my Garmin eTrex. The eTex tracks are always a bit rough too. Yes, the Captivate track does sometimes cut the corner or the curve and is off the street that I actually rode on. But it basically follows my route well. It has always followed me when I loop around a block, or drive down a short dead end and come back. I can definitely tell where I went and what roads I took when I look at the track. I'm not bothered if it shows me 20-40 feet off the road on occasion (as I have noted, so does my Garmin eTrex). I expect this with a 10m resolution.
- Navigation. I've been using the google Navigation app on drives in the car. I mount the Captivate in a mount on the dash, so it has a clear view of the sky through the glass. It's not on the seat, or in the ashtray or in a cup holder. It's mounted to the windshield close to the front, so it has a good view of a broad expanse of sky. This is exactly how I mount the Mio GPS or Garmin etrex or Garmin Nuvi when I use those in the car. Used like this, my Captivate navigation has been excellent. Frankly, its far better app than the Mio or Garmin Nuvi 1390T that I have used. The searches are quick and I like the presentation. Obviously, in Navigation the app knows to lock you on the street. And when I drive past an indicated turn it always notices immediately.
Summary: So I don't know what has changed since my first Captivate, but this one seems fine to me. I don't know if it's the hardware, or the SW update. But so far mine works as well as the other GPS devices I have used. If it keeps working like this for another week, I'm definitely keeping it. I'm sure some have trouble, as I did with my first Captivate. And I do think some others expect too much: I don't expect the Captivate to be "THE BEST GPS" I have ever seen. I expect it to lock within 2 minutes, work for navigation in my car, to find me on a google map and to record a track of where I went. This all seems to be working for me. (And usually it locks in well under a minute for me). I think I'll keep it... if this performance keeps up.
IMO, YMMV
Carl

vintagephone/Carl. Yours is a very useful write up. I use a Garmin GPS for Geocaching, some street navigation and bicycle riding in the country. What you wrote should be very helpful to someone not so familiar with GPS devices in general. Thanks.
= Ron

I completely agree. People looking at 'my tracks' and showing that there are some slight variations - we don't even know if the google maps is 100% accurate, as I know there are certain places where it doesn't match up directly with the road. I think as long as no errors are being presented during navigation (mine is doing fine in navigation mode) there is not really any complaining that can be done. Even my built in car GPS makes a mistakes once in a blue moon.

I'm not sure what Garmin Nuvi you're using, but I have a 2 yr old 250W and it smokes this phone. The phone has me driving through people's yards and buildings. It has gotten better since the JH7 update, its almost what I would call usable now. Try doing a Mytracks track on it, its a joke how far off it is. Its certainly unusable for that.

derek4484 said:
I'm not sure what Garmin Nuvi you're using, but I have a 2 yr old 250W and it smokes this phone. .
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I'm very familiar with the Garmin I used, a Nuvi 1390T. Negatives for the Garmin included horrible traffic reports, and searches for my destination took forever. Basic Navigation was OK, if you knew the address of where you were going. And if you were going someplace more than 30 miles away (a common undertaking in the LA basin), you just couldn't get there. Searches on the Nuvi only include locations within 30 miles. Frankly, the search was much worse than on my old Mio. I had the Nuvi 1390 for a couple weeks and returned i just as I got my second Captivate. For basic GPS navigation, the Nuvi was OK, but I saw no advantage over the Captivate. Are you mounting your Captivate in the same way and place you are mounting your Nuvi? I actually use a modified Nuvi windshield mount with my Captivate, so my mounting is literally identical.
Now, you Captivate my not work as well as mine. My original Captivate was worse than this one. As I said, YMMV (your mileage may vary).

I use a Garmin V GPS receiver for Geocaching and some other activities which demands a very high degree of accuracy. This receiver will use as many birds as it can find (seldom less than five) to determine its location but a cell phone GPS receiver may limit the number of satellites it tracks to conserve battery power.
Using four satellites, the accuracy of the Garmin V typically comes down to a target area that is two to twenty feet in diameter. This unit is fast; I can watch the current location triangle move past streets just as I am able to make out the street signs.
The Captivate I ordered will not be here until later today so I can't report anything about my experience with that device. I have been using an HTC device (AT&T "Tilt") and Google Maps for several years now and can report it has very good GPS accuracy and speed when compared to the Garmin unit. I would be pleased indeed if the Captivate even comes close to the performance of the Tilt.
As with any GPS device, it has to have line of sight visibility with at least three satellites to report its position with any reliability. Clouds (with heavy moisture), trees and tall buildings can reduce GPS accuracy substantially. Bicycling through heavily forested areas reduces the accuracy of my Garmin V from a few feet to hundreds of feet. As it takes a few minutes for the receiver to "lock on" and recalculate its position, after pedaling through a forested area I can be a mile up the road before the display catches up. Even at bicycle speeds (15MPH) I have missed turns simply because of trees!
With the Tilt, moving on foot around tall buildings, Google Maps sometimes can't figure out where I am. In the car, I usually pull the sunroof shade back so the Tilt gets a clear shot at the sky.
One final point: If I have the Garmin running at home, shut it off, then restart it again when I am fifty miles from home, it takes maybe five minutes to find three in-view birds. There is a feature in the Gamin that allows me to move its cursor to about where I think I am and it, then it uses this information to find new birds. I use this feature frequently and it usually saves two or three minutes locking on to a new set of birds. That feature is not available with the Tilt and it can take a full five minutes for it to find three birds when I change location with the GPS receiver turned off.
I hope these comments are useful. A cell phone with GPS capabilities is understandably no match for a single-purpose GPS receiver and particularly so when the two devices sell for about the same price.

I doubt that it is Maps or myTracks that is off (although I had wondered about this as well) because when you run the Captivate side-by-side with an N1, the N1's lock and track are very fast (almost instantaneous) and flawless. Of course we all know the Captivate's lock and track issues. The N1's track would not be so perfect if it were an issue with the base map accuracy, when the app on both phones is the same and accesses the same data.
The issue can also be seen running GPS Status or GPS Test together too, the N1's lock is always better, although I see no appreciable difference in SNR values for each satellite. It is just like the Captivate simply will not lock, even when it sees the same satellites. That is why I am sure it is the driver issue and therefore fixable.
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Google Map update effect GPS

I was wondering if anyone else experienced EXTREME improvements today after updating Google Maps?? I am to 10-20 meters of accuracy compared to the normal 400 meters. It actually shows me at my house which is WAY WAY in the country!

Most of the time I'm at 10 meters, sometimes it'll get to 5 meters. Maybe it's improved, maybe not.

Mines still off by 5-6 miles. Odd because when i first got it my location was only off by 1/2 mile.
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I didn't get to drive but I did get a very fast navigation lock that never happens for me. Also I got a lock inside my house within 10 meters. And the navigation lock was also inside.
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Well I tried it with GPS off, here in australia, and my location was only 2 houses off. This is a massive improvement. But that's just based on cell phone towers i guess.., dunno about actual GPS improvement but that would also be nice

Noticed this as well. Was in Orchard Supply earlier and tried out the GPS because my brother was asking about it (he's been thinking about getting captivate). Was able to get a very accurate lock INSIDE the store showing in about 20 seconds where I actually was in the store which was nuts (actually it was pipe fittings aisle ). Tried navigation home from class during the afternoon and it took about 10 seconds to get a lock and never lost me the whole way. My GPS was working fine before but now it's even more accurate/faster.

I second this. I tried with the GPS at home. Locked very quickly, and about 10 meters. Navigation seems working fine too.
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Sounds like GMap finally defaults to use A-GPS mode which means faster lock. Accuacy? Not affected.

TRY THIS
Referring to INDOOR accuracy with GPS module off.
I'm noticing that if I have WIFI AND USE WIRELESS NETWORKS ON, the indoor accuracy has improved massively. If I turn WIFI OFF but leave Use Wireless Networks ON, I seem to get standard cell tower location of 500 - 1000 meters.
So, Im assuming this update has enabled Google's version of Skyhook in maps.
Im pretty sure thats what it is since I dont have to be connected to an access point for it to work. Just have WIFI ON.
Nice.
Everyone should disable Skyhook from the LBSmode. I had it disabled since my phone got updated to JH7 but for those how don't...
My settings from factory are:
Skyhook OFF
GPS plus OFF

I to see a improvement. I drive 80 miles one way to work and never lost lock. This has never happened before.

What is GPS plus?
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drfubar said:
Referring to INDOOR accuracy with GPS module off.
I'm noticing that if I have WIFI AND USE WIRELESS NETWORKS ON, the indoor accuracy has improved massively. If I turn WIFI OFF but leave Use Wireless Networks ON, I seem to get standard cell tower location of 500 - 1000 meters.
So, Im assuming this update has enabled Google's version of Skyhook in maps.
Im pretty sure thats what it is since I dont have to be connected to an access point for it to work. Just have WIFI ON.
Nice.
Everyone should disable Skyhook from the LBSmode. I had it disabled since my phone got updated to JH7 but for those how don't...
My settings from factory are:
Skyhook OFF
GPS plus OFF
Click to expand...
Click to collapse
Wi-fi location fix has been in Google Maps for a long time now. It is not new.

Here's my opinion on this. I have nothing to back this up other than what I interpret from behavior I have seen, so it is strictly my opinion/guess.
Ignoring any GPS hardware or software issues there may or may not be, I think that Google Nav has issues from time to time. I don't know if it is because it relies on 3g data to paint maps and determine routes or whatever, but I think it seems to "lag" sometimes. And if it gets a bit off track, it takes too long to recover. Maybe it does it more on a system that struggles with GPS accuracy a bit more, I don't know.
So, my guess would be that an update to Google maps would not contribute anything to a faster GPS lock or more accuracy from GPS, since I guess this happens at the OS level.
However, what we see when navigating, is Google NAV(maps) interpretation of the GPS. So, when it teleports you off the road maybe it's because it isn't smart enough to think, "Hey, a car doesn't just teleport off a road, so I'll wait a couple more seconds to see if it returns before I show it off the road". It already does this to some degree since your accuracy under good conditions can be 10 or 15 meters which could easily put you on a lawn or sidewalk but NAV continues to show you on the road.
So, maybe, Google Maps updates can help make the Nav experience better by being smarter about interpreting GPS data and showing your position within the context of driving a car down the road.
My $.02
Bob

foxbat121 said:
Wi-fi location fix has been in Google Maps for a long time now. It is not new.
Click to expand...
Click to collapse
So do your maps show better accuracy or not? Since that is the topic of the thread you might as well refer to the topic. Or are you just trying to show everyone you know better?
One thing is that the feature was there, another is if it worked properly.
Now it works. Before it didn't.

My navigation isn't the best but I am thrilled to have a quick lock in the boonies where I live... GPS worked decent but lagged in little rock our biggest city.... but I haven't been to the city since the update... I'll let everyone know if it can now navigate there. ... I know my location contributes to the issues!!!! But again I was thrilled to be getting locks!
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I updated Maps yesterday and the AGPS sometimes says I'm in Georgia now(I live in PA), lol, in the middle of a highway no less. However the GPS is working better. I got my first lock ever as well as the first time my GPS has ever seen more than 3 satellites(saw 6).

All I can say is that I would be VERY surprised if an update to Google Maps helped GPS locking, how many satellites it sees, or accuracy at the GPS layer on the device.
However, I would not be surprised if a Google Maps update helped with navigation use or even placing you on a map, since it Google Maps can modify it's interpretation of the GPS position.
If your GPS was spotty before, then thinking you are seeing more satellites or better accuracy, using something like GPS Status, is just a placebo.
However, this is pure speculation on my part. I suppose it's possible that Google have modified something at the device layer that controls the GPS chip, but I'm thinking not.
My feedback would be to exchange your phone if your GPS is spotty. I did and my new phone has pretty much perfect GPS.
Bob

How can you tell the actual accuracy in ft or meters in google maps?

If anything for me GPS lock is take longer than before update.

mudfarmer said:
Mines still off by 5-6 miles. Odd because when i first got it my location was only off by 1/2 mile.
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If it is of by that much it is only giving you a network provided location...not a gps position. Turn off use wireless networks to see a gps location
Sent telepathically using vulcan mind meld app.

gps lock trouble

So half of the time when i use my gps, it will lock me with towers and be up to like 1600 meters or something. and one time i let it sit for 10 minutes and it got no closer. If i toggle the gps on and off once or twice though it will work usually (and it works fast when it does). also one time i just restarted the phone too.
anyone else see issues like this?

My GPS issue is that even though it locks on within 7 seconds when I run Cardio Trainer it always shows me at least 1.5 to 2 tenths of a mile farther than I have gone. I have checked the distance with my Vibrant and also with my Nexus One and they both show the same distances. For whatever reason the MT4G seems to add on distance not traveled.

mine doesn't like to lock on, but before I goto nav I just go load GPS status and reload the aGPS info every so often and keeps it honest

This phone definitely has gps that is inferior to one in G2 or even G1. However, my gps has no problem locking on and holding on to my exact location. Every now and then it losses orientation and spins the map around but that only lasts a sec or two and only happens when its cloudy or in downtown. Get your phone replaced I would say.
Sent from MT4G.

[Q] Is my GPS chip defective ?

Hello,
I'm encountering some issues with my Samsung Nexus S GPS. I got the i9023 (Europe/SLCD) version of the phone, which is running default rom (stock), freshly updated to 2.3.4 (via official OTA!).
I couldn't figure why, when using Maps, my position would usually be around 1 km away from where I am. I found out later, this time using Navigation, that it is desperately searching for a GPS signal, that it can't find. Sometimes I manage to get a lock, when I keep it running for like 30 - 40 mins, but it immediately disappears. GPS Statuts keeps showing 0/5 sats.
I was convinced that my GPS chip was defective.
But today, I was hanging out in the city and tried running Navigation. I got a lock, for the first time, within a 15 sec delay. That was the first time that I managed to get live GPS tracking. I've walked a bit around, and the tracking was really, really accurate.
Back home, in my apartment, again I can't get any signal. I live in the 3rd floor, walls aren't that thick and, as for an anecdote, in the same room, my iPhone 3Gs instantly finds my position.
I've bought this phone 6 days ago and therefore still under warranty. Question is, can we say my GPS chip is defective ? Is it worth requesting a replacement ?
Thanks !

1st) You cannot expect to get gps reception inside even with professional equipment. When your iPhone gets a fast fix it's most likely WLAN triangulation. As Apple uses a different database than Google, it may work on on your iPhone and not on your Nexus for a paticular place and vice versa.
2nd) It's unlikely that your gps is broken if you can connect to GSM/UMTS/CDMA2000 networks as gps is processed using the same chipset.
3rd) That 1km-off-fix might be celltower based location, 1km sounds quite plausible.
4th) Try _NOT_ to move until you get GPS fix.
5th) Keep internet access while trying to get a fix. The Nexus S as most phones on the market use assisted gps, where your phone contacts a server that provides data which enables your phone to track its position more easily.
6th) Good luck.

Yes, well, I had 2 friends which came to my place, in my room, and just activated GPS on their iphones and it located them straight away, to our exact position. So it was definitely the GPS tracking and not triangulation.
Indeed, when MY phone locates me off 1 km, this is definitely triangulation or cell-towers.
Of course, when I try to get a fix in my apartment or on my balcony, I just put it on a table and must wait for at least 30 mins to get a lock, and it disappears quickly. Doesn't seem normal to me ...
Finally to answer your 5th point, I got 3G, so a perfect fast & smooth inet connection.

GPS testing should always be done outside, you are not supposed to use it indoors.
What is probably happening there is that the other devices are more sensitive and can still get a lock. You might be able to get a lock if you place your phone very close to the window.
I got a Nexus S recently and noticed that the GPS is quite weaker than the one on my old HTC.
Although the Nexus is faster to get a lock (if you let it use 3G) the GPS itself is less sensitive and accurate.
It looses signal easier, for instance, if i go under some trees, and it takes more time to get signal back after loosing it, for example, if you go under a bridge, the old HTC would get the lock back in 2 seconds after leaving the bridge, the Nexus took half a minute.
Having said that, i think it's good enough for driving navigation, i have done some tests and on the road it behaves well enough.
You shouldn't be surprised, this phone is very similar to the Galaxy S and that had terrible GPS issues, this nexus is better, but still weak.

Thank you for your feedback, temp9300 !
I guess the Nexus S can't compete with iphone's. But it's ok, as long as it works fine outdoors, this is what matters.