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Phil_n
Newbie
Joined: July 30, 2009
Posts: 8
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 Posted:
Aug 20, 2009 - 12:36 PM |
 
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| Post subject: iphone 3GS - GPS in Shanghai / China |
I have used the Maps app in both my old 3G and now my new 3GS.
Although it has helped me out many times when driving around, the GPS is actually never accurate.
When I open maps and click the locate me button it starts with a Big blue shaded circles which quickly narrows down to a smallish circle but the blue dot is ALWAYS something like 100-200 meters off and however long i leave it on it never gets more accurate.
This app is nevertheless useful as it does give me a rough idea of where I am and in which direction i am going in but it would be so much better if it was pinpoint accurate. I have read many forums on this and it seems this does work well in Europe / USA.
I have asked some friends who also have the iPhone and they all seem to have the same problem.
I used to have an in-car GPS which was generally very accurate. Wondering why the iPhone GPS is not.
Has anyone has that problem? Does anyone know how to fix it? |
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BoShiDunRedSox
Barker
Joined: July 07, 2008
Posts: 181
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Aug 20, 2009 - 12:58 PM |
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I get different results, depending on which app I'm using, and whether the app is using network triangulation or GPS. Neither method seems to be accurate, but on occasion, it's been within 50m.
I intalled tomtom this week, and will use it on an upcoming trip to the US. Hopefully it will work better than the existing apps I have. |
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7thGreen
Lurker
Joined: July 29, 2009
Posts: 36
Status: Offline
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Aug 20, 2009 - 01:10 PM |
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it appears the iphone just shows you the location of the tower in which you are connected. I haven't noticed a triangulation to determine my exact location in the standard app. to my knowledge the iphone does not have a GPS receiver.
In my car GPS, because of the tall building in SH. i only get a sat signal a few times a day. however, because it is built into the car it calculates my location based on the last GPS signal then the system compares distance and direction against the map to determine my location. basically the more turns i make the better it knows where we are. |
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Phil_n
Newbie
Joined: July 30, 2009
Posts: 8
Status: Offline
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Aug 20, 2009 - 01:47 PM |
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| 7thGreen wrote: |
| to my knowledge the iphone does not have a GPS receiver |
The 3G and 3GS iPhones most definitely have a GPS receiver.
I have a feeling the accuracy is deliberately off for some unexplainable reason, but that's just a feeling. |
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blueeagle
Seeker
Joined: June 21, 2007
Posts: 47
Status: Offline
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Aug 20, 2009 - 01:54 PM |
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My 3GS works very well in US. Very quickly pin point my location accurately. In Shanghai on the other hand doesn't work that well. It quickly give me a general idea where I am, but can't seem to pin point my exact location no matter how long I waited. So pretty much the same experience as OP. Not sure why, maybe the GPS receiver can't get a lock cause of the tall building around or because of the layer of grey stuff in the sky that perma-cover Shanghai.
Anyone experience 3GS in places like Manhattan, NYC? |
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Phil_n
Newbie
Joined: July 30, 2009
Posts: 8
Status: Offline
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Aug 20, 2009 - 02:13 PM |
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I have tried using my iPhone GPS in the countryside with no interference at all - same problem
Used it in the mountains around Guilin (little or no pollution) - same problem |
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defender
Newbie
Joined: Sep 02, 2009
Posts: 1
Status: Offline
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Sep 02, 2009 - 02:36 PM |
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Check out Wikimap. It allows users to save open street maps (osm) for offline map nagivation and browsing. It also allows new waypoints and new pictures to be uploaded which are automatically shared to other Wikimap users.
http://wiki.alumni.net/wiki/Wikimap |
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trader889
Lurker
Joined: Oct 22, 2004
Posts: 31
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Sep 02, 2009 - 03:41 PM |
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There's nothing wrong with your iphone. All GPS units sold outside of China, due to Chinese regulations, must be slightly shifted from the actual map grip. This is a common problem. Locally bought GPS units solve the shift problem. For example, Garmin has teamed up with Unistrong in China to sell GPS units without the shift problem. How to solve it? Not sure if somebody has it solved for the iphone. Ask computersolutions, he will know. |
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blueeagle
Seeker
Joined: June 21, 2007
Posts: 47
Status: Offline
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Sep 03, 2009 - 09:47 AM |
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My Nokia N95 on the other hand can pin point my exact location pretty well here in Shanghai. The only problem with that, it took several minutes for the device to "lock in" your position. I bought the phone in US, although I hacked it to install Chinese OS so I can read Chinese characters. Maybe that's why it works really well in Shanghai.
So, if that is the case, it means that there must be some software hack that can fix our iPhone GPS problem. I wonder if the iPhone sold through unicom will have similar issue or not. |
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PNWer
Barker
Joined: Oct 18, 2007
Posts: 177
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Sep 04, 2009 - 05:34 PM |
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compsolutions
PopStar
Joined: Mar 07, 2009
Posts: 1096
Location: Shanghai
Status: Offline
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Sep 04, 2009 - 06:20 PM |
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GPS (for non miltary use) is usually to within 50sqm anyway, plus the maps are off for security reasons.
As an aside, apparently thats what the american's said about bombing the Chinese embassy in belgrade, cough bullfeces, cough.
You can get better results triangulating, but as people say above, government doesn't want you to. And you *REALLY* don't want to be messing around with that unless you fancy a long free vacation courtesy of the government.
Read here for offset error info: http://www.kowoma.de/en/gps/errors.htm
Also bear in mind Shanghai = lots of tall buildings.. bad for reflections. |
_________________
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menos
Seeker
Joined: Mar 28, 2008
Posts: 65
Status: Offline
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Sep 08, 2009 - 12:33 PM |
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At the moment I am still using a ~2 year old Samsung i780 with GPS + "Mapking 2007" software with mapking files.
I use the i780 to navigate by foot and car in the PRC and Hong Kong and found it very quick und accurate.
I have no trouble, to get a very quick lock (less than 30 sec most of the time).
I think about getting an iPhone though (Windows Mobile annoys me).
1.) Is there a GPS software for the iPhone of similar performance, so I can leave the Samsung at home?
2.) How is battery life with the iPhone and GPS?
I can use my Samsung i780 for 2-4 hours, navigating on battery power until I have to change the battery or plug it in the car charger. |
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Jumme
Newbie
Joined: Aug 22, 2009
Posts: 2
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Sep 09, 2009 - 12:36 AM |
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I use Nokia N82 with Garmin XT GPS to navigate while in Shanghai.
Though I know about the offset error, it doesnt seem to be a problem, even in central area (tall buildings).
If anyone here have a java enabled phone, (many Nokia and others) Ill be happy to assist with installation.
(Im only here until this saturday, though). U'll need to bring a memory card/storage. |
_________________
Danish guy in Shanghai |
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Ginger555
Seeker
Joined: Feb 20, 2009
Posts: 66
Status: Offline
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Sep 22, 2009 - 01:00 PM |
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The iPhone doesn't have GPS ... it has that wierd A-GPS hence the issues with it not being accurate in China ... the USA has more towers so more accurate. The new iPhone 3GS has a built in electronic compass that makes the A-GPS better but still its not the real thing.
http://en.wikipedia.org/wiki/Assisted_GPS
And for A-GPS you have to use your data on your iPhone and in China data is charged per minute so depending on your contract can get expensive to use. |
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menos
Seeker
Joined: Mar 28, 2008
Posts: 65
Status: Offline
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Sep 22, 2009 - 01:40 PM |
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Ginger, the Samsung has A-GPS too and works nicely in the PRC and Hong Kong.
I can disable the data service by menu and have significantly longer times for an initial GPS lock. It works too though if needed.
I run it with a monthly data prescription with a M-Zone card.
It is very reliable and I use it very often, when navigating in unknown areas. I have had no issues with map offset and normally navigate from door to door quite precisely. |
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foos
Lurker
Joined: June 24, 2009
Posts: 24
Status: Offline
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Sep 22, 2009 - 02:05 PM |
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| Ginger555 wrote: |
| And for A-GPS you have to use your data on your iPhone and in China data is charged per minute so depending on your contract can get expensive to use. |
Actually, China Mobile charges by the MBs. Their GPRS data plan is very affordable. I've been on the 20 RMB/month for 150 MB data plan for months now with frequent use of Google Map, Garmin, Opera, and Gmail on my Nokia N86. I have yet exceeded the 150MB plan limit. I don't know about China Unicom. But I doubt they dare to charge more than China Mobile.
Btw, if you can download 24x7 on your cell phone, China Mobile has an unlimited GPRS data plan for a few hundred yuan. |
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foos
Lurker
Joined: June 24, 2009
Posts: 24
Status: Offline
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Sep 22, 2009 - 02:19 PM |
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| menos wrote: |
Ginger, the Samsung has A-GPS too and works nicely in the PRC and Hong Kong.
I can disable the data service by menu and have significantly longer times for an initial GPS lock. It works too though if needed.
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My Nokia N86's A-GPS works fine too.
Google Map for Symbian is good! I drove to Suzhou last weekend with it, and it worked just like a real GPS, except for the lack of voice directions. The phone's GPS and Google Map had been tested in the streets and alleyways of Beijing, Shanghai, Suzhou, and New York City since I got it, and it was very very good. |
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KentWang
Newbie
Joined: Sep 13, 2009
Posts: 7
Status: Offline
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Oct 10, 2009 - 09:19 PM |
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I used a iPhone 3G and also had inaccurate GPS, usually about 1 km off. |
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KentWang
Newbie
Joined: Sep 13, 2009
Posts: 7
Status: Offline
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Oct 10, 2009 - 09:26 PM |
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To answer some above posters:
iPhone since the 3G has real GPS, not just A-GPS.
GPS offset has been turned off by the US military a long time ago.
This seems viable but doesn't explain why some GPS devices are accurate in China.
Overall, I have no clue why it's inaccurate. |
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netzwerg
Barker
Joined: Sep 30, 2009
Posts: 130
Status: Offline
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Oct 11, 2009 - 10:01 AM |
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| KentWang wrote: |
iPhone since the 3G has real GPS, not just A-GPS. |
A-GPS IS real GPS, plus the feature of getting the Almanach data (= which sat is where at what time) via GPRS with EDGE speed of 200000bit/s, and not over the 40bit/s downlink from the GPS satellites. That enables sat fixes in seconds with enabled A-GPS, not minutes like with GPS.
If the Almanach data are downloaded either via GPRS or from the GPS-SAT, an A-GPS enabled devices works just like a regular GPS device. The A- in A-GPS is just used before sat-fix. |
Last edited by netzwerg on Oct 11, 2009 - 10:06 AM; edited 2 times in total |
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netzwerg
Barker
Joined: Sep 30, 2009
Posts: 130
Status: Offline
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Oct 11, 2009 - 10:04 AM |
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| foos wrote: |
| menos wrote: |
Ginger, the Samsung has A-GPS too and works nicely in the PRC and Hong Kong.
I can disable the data service by menu and have significantly longer times for an initial GPS lock. It works too though if needed.
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My Nokia N86's A-GPS works fine too.
Google Map for Symbian is good! I drove to Suzhou last weekend with it, and it worked just like a real GPS, except for the lack of voice directions. The phone's GPS and Google Map had been tested in the streets and alleyways of Beijing, Shanghai, Suzhou, and New York City since I got it, and it was very very good. |
Same with my E71's GPS and google-maps as well as Nokia maps. Just as accurate as in Europe or elsewhere in the world. Great feature if you get lost here. 
Even downtown between the skyscrapers it works fine. no inaccuracy at all. |
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mindmix
Squeeker
Joined: Oct 13, 2009
Posts: 19
Status: Offline
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Oct 14, 2009 - 09:23 PM |
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| netzwerg wrote: |
| foos wrote: |
| menos wrote: |
Ginger, the Samsung has A-GPS too and works nicely in the PRC and Hong Kong.
I can disable the data service by menu and have significantly longer times for an initial GPS lock. It works too though if needed.
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My Nokia N86's A-GPS works fine too.
Google Map for Symbian is good! I drove to Suzhou last weekend with it, and it worked just like a real GPS, except for the lack of voice directions. The phone's GPS and Google Map had been tested in the streets and alleyways of Beijing, Shanghai, Suzhou, and New York City since I got it, and it was very very good. |
Same with my E71's GPS and google-maps as well as Nokia maps. Just as accurate as in Europe or elsewhere in the world. Great feature if you get lost here.
Even downtown between the skyscrapers it works fine. no inaccuracy at all. |
Google map in China are the old one. Chinese govement will not let google to update satellite. |
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PureXTC88
Reacher
Joined: Mar 24, 2003
Posts: 369
Location: Toronto / Pudong
Status: Offline
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Oct 15, 2009 - 11:32 AM |
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I use a combo of Google Maps and Route66 on my Samsung i8910HD and it works very well. Unfortunately Rout66 is only in Chinese, I wish they had Pinyin. |
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TISM
SuperStar
Joined: July 14, 2005
Posts: 1581
Location: Shanghai
Status: Offline
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Oct 17, 2009 - 08:25 PM |
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| mindmix wrote: |
| netzwerg wrote: |
| foos wrote: |
| menos wrote: |
Ginger, the Samsung has A-GPS too and works nicely in the PRC and Hong Kong.
I can disable the data service by menu and have significantly longer times for an initial GPS lock. It works too though if needed.
|
My Nokia N86's A-GPS works fine too.
Google Map for Symbian is good! I drove to Suzhou last weekend with it, and it worked just like a real GPS, except for the lack of voice directions. The phone's GPS and Google Map had been tested in the streets and alleyways of Beijing, Shanghai, Suzhou, and New York City since I got it, and it was very very good. |
Same with my E71's GPS and google-maps as well as Nokia maps. Just as accurate as in Europe or elsewhere in the world. Great feature if you get lost here.
Even downtown between the skyscrapers it works fine. no inaccuracy at all. |
Google map in China are the old one. Chinese govement will not let google to update satellite. |
My E71 with Google Maps is very accurate and also includes traffic. Also great for working out which bus to take with the transit directions |
_________________
Everyone will be famous for 15 minutes. |
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netzwerg
Barker
Joined: Sep 30, 2009
Posts: 130
Status: Offline
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Oct 18, 2009 - 12:33 AM |
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| mindmix wrote: |
| Google map in China are the old one. Chinese govement will not let google to update satellite. |
I dont know what google maps you use but mine on my e71 is very up to date, accurate and uses layers like traffic, wikipedia or transit lines (subway, busses, trains). I can even see on which side of the road i am standing. |
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