All Maps in China are Transformed
By Jian Shuo Wang on 2008-11-09 14:26 · Hi-Tech ToysThere are rumor that all printed maps that is available in domestic market are transformed. The goal is to make the map useless for military situation to protect the safety of the country.
I heard about it but I didn’t really believe it. I thought to protect the country from foreign intelligence agents by transforming all maps available in a country is just a fool decision.
I do know that in certain Shanghai map, because of the streets in downtown is so crowded, and in other places, density is lower. So they transformed the map to cover as much as places possible while keep the downtown street clear enough to recognize.
However, the rumor is not about this specialize map. It is about all maps in China.
Google Map Revealed the Secret
In most places in China, Google map has a feature to hybrid map and satellite images. I found that handy. In China, however, there are no this feature.
Recently, Google added traffic map. When traffic map overlaid on top of local map, it fits each other perfectly. If the map is overlaid on a satellite map, you see the huge transformation.
Google Traffic on Map
Look at this: the traffic line and the map fit each other perfectly. You see the yellow line as Huashan Road - the road before where I work, and the green thin line is Huaihai Road, and the upper left double green lines are Elevated Highway.
Google Map on Satellite Maps
Look at this again.
The traffic lines are still there, but if you see the reality - the satellite image, you will find out the maps are completely transformed. The real Huashan Road is about 300 meters west of what is shown on the map, and the Huahai Road is actually 200 meters north of it. Meanwhile, it is not a consistent transforming - it is very random.
I checked other maps, and my conclusion is:
Look at a Chinese map, the real location may be 0 - 500 meters north, south, west, or east (randomly) of what the real location is. You have no idea about where the real location is because the transform is random.
It is Not a Problem of a Map Provider
Is it the error of a single map provider? In this case, is mapabc.com, the map source that provided the wrong data? I don’t think so. I talked with Google people about this, and talked with map expert. It seems all the maps are transformed.
I Hope We Release Real Map
Civil usage of GPS was once forced to add some noises so it is not accurate as GPS technology can provide. Now, the ban was lifted, and people can get knowledge of where they are via GPS.
I don’t think today, we can protect anything just by transforming a map. It reminded me about the claim of many local “map experts” that Google maps has released the national secret of China. I think the real national secret is, how narrow minded the “experts” are.
32 Comments
I enjoy reading your blog -thanks for the interesting posts.
However, while some maps are altered (in the UK, where I'm from, the standard OS maps miss many details close to armed forces bases, etc) and I'm sure it happens in China too, the Google Maps issue you've spotted is not down to this.
The transformation is due to a different map projection type being used on the map source used by Google. If you're interested you can read about map projections here: http://en.wikipedia.org/wiki/Map_Projection.
I live in SH and use a Internet Tablet / GPS device which takes it's images from maps.google.com (and ditu.google.cn) and I have to set an "offset" to show the maps in the correct location. The offset is not random, it is the same deviation N/E every time this map source is used.
Cheers,
John
i will be in Shanghai soon too and also face the problem with the offset i have seen on Google Maps. Can you tell me how you did this in your software and maybe provide some offset data for me?
So is it true the Map data is correct and only the satellite images are mapped wrong due to the projection method google uses?
Thanks in advance
Dagobert
PS: Maybe we can meet in Shanghai in March when you tell me the coordinates. Then you can show me. :)
the bad thinks is the "direction function" is based on the map and not on the satelllite so basically the device will ask you to turn when it's yet too late or too early creating a big mess!!
how come no one talk about this? :( I want t ouse my Iphone as GPS!!
thanks for your help
This really sucks as I can care less about the satellite view. I wish there's a way we can set the offset in Maps in my iPhone but I don't see many people care about it to even talk about it. I can't find anything in google about this at all.
This is actually the first site I found that talked about it but I was actually searching for "How to report google map problem". : /
Friends with Android phone, take a try and see if your problem fixed.
So finally, I found some other people with the same frustrating experience as me! It's been driving me crazy and I keep re-installing my software hoping to see a difference... the latest 3.0 update still didn't help with the offset, but made it really clear on my iphone where the offset was once i could see the traffic maps. And just to reiterate, it is the MAP that's offset, the SATELLITE is perfect.
So if China Unicom is going to launch the iPhone in China later this year, should we expect a fix to this soon? Otherwise you're going to have millions of people with legitimate phones who are going to be pissed the GPS functions blows chunks. Since I had to "hack" mine to work, I accept a certain loss of functionality or convenience... but not for long.
The reason for this seems to be that locally made GPS devices are all corrected via firmware for this offset. So either they want to protect local gps brands or it has to do with military reasons that all maps have offset (which sounds like an outdated method anyway)?
I also have other (foreign) gps device which has exactly same offset (so the offset is definetly in the maps, not in the gps). Did not find any solution for e.g. google maps or google earth (if you have an easy way to "calibrate" either the maps in google maps or the tracks with offset, then let me know)
If I didn't need to pin point my position on Maps with GPS, it would work just fine as a regular map.
http://forums.groundspeak.com/GC/lofiversion/index.php?t154946.html
The satellites we all use today for GPS navigation is controlled by US. I guess the data transmitted by satellites can be manipulated by US whenever necessary. So in theory the reading of every GPS device can be controlled by US. This certainly makes Chinese government nervous. They want to use their own GPS navigation satellites. By providing erroneous map data they try to discourage the use of existing GPS platform. Ideally all those random errors can be only perfectly corrected by using the data transmitted from China-made navigation satellites in the future.
I doubt China will launch their own Sats as it is too costly and I don't really see a need for it. If they need to rely on other means of location service, they can always use the massive cell phone network.
I do really believe the problem lies with Google maps and some Chinese policy. I'm wondering if iPhones sold in China have this problem? That would suck cuz their iPhones are already lacking wifi.
I have bought a garmin zumo 550 gps in denmark and the china navigator map from canada.
It did not work here in China because of the off set of approximately 400 meter.
Have tried every thing, downloaded the bin file, talked to garmin, updated my garmin, downloaded maps from the net. Nothing worked.
Then I found www.vttown.com
Shanghai company.
They just wanted type, model and id number of my garmin and 2 days later I got the navigator map and every thing works perfect.
So if you have problems contact vttown.
hi
michael
No offense but the "military" excuse just doesn't make sense. Anyone can come here and buy a GPS that works perfectly. So in a sense, any military from any country can buy one. Heck, I can buy one and send it anywhere in the world. Then extract whatever code and apply it to their GPS system.
The more realiatic view on this is just money. You can't buy GPS from outside China so people will need to buy it in China. Simple as that.
ABCMaps applciation.
http://itunes.apple.com/us/app/abcmaps/id379582726?mt=8
In China, the built-in iPhone Maps application is distorted and will
show you a position that is 300-1000m randomly from reality. The
ABCMaps application is to align the maps to the real place.
ABCMaps is Chinese only applcation now. However, it is so easy to use.
So even you can not read Chinese you can use it also. The English
version will come out in the future.
http://itunes.apple.com/us/app/abcmaps/id379582726?mt=8
Find out where you are really in China. If you travel in China,
sometimes you will be troubled by China maps offset. The ABCMaps application is to align automatically the maps to the real place .
If available in your area, real-time traffic conditions will be
displayed over the road as color-coded lines by click "Traffic" button.
What's New In Version 1.30
1. English support added
2. Traditional Chinese support added
3. Small bug fix for iOS 3.0
What does this mean? Well it means what I'bebeen saying: that only the google map is affected, on purpose.
I don't know exactly how ABC Maps re-align the gps coordinates but I know that's the only thing they did because if you switch between street and sat view, they still don't overlap exactly. ABC maps simply aligns the gps coordances and put them on the map view. Perhaps they simply use the sat views coordinates for the map view because the sat views are correct in the default map program.
But great start nonetheless. The ads do bug me a little and I honestly would pay money for this if it had more features and remove the ads. I've already used it a few times and the gps locations are spot on. Hope there will be more updates to come.
That's how closed societies tend to do things, but it's really obsolete now as any random civilian gan get decent uncensored sat-maps and accurate geopositioning.
The mismatch between satellite map and street map is just because they use different coordinate system.
Generally speaking, the earth is a 3D object while the map is 2D. So we have to choose a mapping function do map a 3D coordinate (spherical coordinates) to a 2D coordinate (x,y). There isn't a perfect global mapping so different countries choose their own mapping. In China, we use Krasovski system(Beijing 54) and then moved to Xi'an 80 system. All the street maps made in China are based on this system. However, the satellite map is made outside China by a WGS84 system. So you will find some mismatch between the two systems. You can also find the mismatch in Russia and many other countries which made their fundamental geographic information with another system.
Also, there is a law that you can't use a common coordinate system (like WGS84) to make map in China.
Now I dare say there won't be a logical answer to this but Why Oh Why! This is nonsensical if the US military wanted to bomb China they won't be relying on google maps. Either this is completely paranoid and illogical (wouldn't surprise me at all in China) o there must b some commercial reason behind this that benefits Chinese companies. Any explanation much appreciated particularly in regard to the google collaboration but. Cheers