All Maps in China are Transformed

There 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.

by Jian Shuo Wang on November 9, 2008 under Hi-Tech Toys

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Comments

If the rumor is true, then how can GPS device work in China?

Posted by: JH on November 14, 2008 5:24 PM

Hey,

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

Posted by: John Levermore on November 15, 2008 1:28 PM

Hello 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. :)

Posted by: Dagobert on January 29, 2009 9:30 AM

@Dagobert, if you just need to get directions, the transformed map is OK since the relative locations of the map is workable for you. However, if you use GPS, that can bring a big problem.

Posted by: Jian Shuo Wang on January 29, 2009 7:23 PM

That means GPS isnt working in Shanghai (for example)? How can there be Navigationsystems for cars? Or do they get real maps? I did a fast check on Johns offset tip and it seems everywhere is the same offset. So this would lead to my assumption the streetmap is accurate like he mentioned but not the mapping of the google satellite view. Maybe its really only a projection problem of google?

Posted by: Dagobert on February 3, 2009 9:47 PM

yeah I noticed on my Iphone....basically the SATELLITE VIEW show the correct position, instead the MAP is offset.
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

Posted by: Gio on February 10, 2009 6:48 PM

You're not alone Gio. I am in Guangzhou and it's the same thing. The GPS of the satellite view is perfect. Switch it to map view and I'm off 300-400 meters of where I'm suppose to be.

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". : /

Posted by: Ryo on March 28, 2009 2:10 AM

If you're using an Android mobile and get trouble on the incorrect my location because of the transformed maps, just try this application: http://sites.google.com/site/hereimapp/english

Posted by: aleung on May 10, 2009 11:11 PM

I am using HTC magic and also have this issue. But today(Jun 16), I update google map program from "market". It seems this deviation issue fixed.

Friends with Android phone, take a try and see if your problem fixed.

Posted by: Jimmy H on June 16, 2009 8:40 PM

Hello!

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.

Posted by: shanghai_iphone on June 26, 2009 5:24 PM