There's a couple of regulations for selling GPS enabled devices in China (I am a software guy on a major PND manufacturer with products being sold in China).
- The map data is scrambled (GPS coordinates are encrypted).
- To correlate a GPS position with the map data, you plug the HW position through an encryption library (which you have to compile in a specific government building in Beijing).
- Border drawing is strongly regulated: no border line between Mainland China and Taiwan, Tibet is of course China, South East Asia Islands can't have border lines drawn and Kashmir is a big thing also with border lines.
- You can't show pure GPS coordinates
- You can't include a number or POIs in your map (mostly government buildings/facilities).
As a note, India as a certain degree of insanity as well: You can't export a map. Launching a PND there involved shipping a bunch of map technicians there to actually make sure we never got a map outside of India...
so what you're calling scrambling/encryption is actually a transformation? the encryption library transforms the coordinates so that they match the distorted map?
what is the advantage of this? couldn't an attacker get a copy of the software? is there some kind of real-time authorisation step so that they can disable the transformation or change it?
[edit: thanks; wasn't thinking you thought it a good idea, just curious for more info]
What this reminds me of is USA's inane attempt to control encryption technology. Every state is used to controlling information, the tech is just moving too quickly for bureaucracies to even respond.
I'm sure there are thousands of Chinese engineers with careers transforming map coordinates. You don't want to put these people out of a job, do you?
Back in the early 90's (in the US) I had a friend who was a college student from China. In the common area of her dorm there was a huge wall-size Rand-McNally map of the world. We were looking it over.
"There's China" I said. "And there's Taiwan."
"You know Taiwan is really not that big." she said.
"What do you mean?"
"Map makers show it larger than it really is in order to exaggerate its importance."
I was a little weirded out by that idea. This girl was pretty intelligent, she seemed to know some math and logical thinking. She was in the process of becoming a CPA.
For better or worse I responded with practical analysis: "How would that even work? You and I could go buy maps right now for navigating ships and airplanes, those would have to be accurate in order to function. We could compare them to this one and if they are noticeably different we could complain and the company that made the map would lose face. Why would Rand-McNally give a shit about the political importance of Taiwan anyway, enough to risk their own credibility?"
"They just do. All map makers do this." She would not be convinced.
those would have to be accurate in order to function
The most common form of map, Mercator projection, greatly distorts the area of land around the equator, and makes northernly (& southerly) lands appear much larger. It makes Canada, Greenland, Alaska, et al. appear quite large compared to Africa & South America. But those areas are much larger.
Are you suggesting that in this case the blogger is similarly misinformed or deluded?
I don't think it's unreasonable to think that China is manipulating its map data, particularly when other people here in the mapping industry have already said this is well known in their field.
You knew her disposition. (You were her friend). What was the goal of that comment, to incent a fruitless political discussion?
Edit: Whoa there. Why the downvotes? I am genuinely curious why the parent decided it was a good idea to stoke that discussion. I have friends whose political views are far from mine, and there are just DMZ topics that I don't dare bring up. For example, a discussion about the Federal Reserve and Operation Twist would be fruitless with my Libertarian friends, who just have a different opinion on that, which I believe is irreconcilable. I would say that's the same situation with Taiwan-strait politics.
It seems like there is little tactical payoff in doing this, as large, foreign militaries would already have detailed, accurate maps covering the whole world, China included. I bet this is an internal-resistance oriented policy.
Even then, if there were an internal-resistance movement that was well organized enough, they could get around this stuff. Seems more like it's there to keep some bureaucrats employed and possibly to prevent lone-wolf resistance 'fighters' who might not be well organized/smart enough to get around these measures.
There are several tools that allow you to compare OpenStreetMap and Google Maps by overlaying partially on the other. Here's one of the area in question:
How is this news? I work in the digital mapping world and there everybody knows this. You cannot even get the data out of China, all data has to stay within China and if you want to do map business in China, you can only do it through a joint-venture with a Chinese company.
[edit] BTW: India is similar, they are not scrambling the map, but it cannot leave the country either. So as a map-maker you have to have a local company there in order to do business.
Getting detailed maps in lots of coutries is difficult. Lived in Ethiopia for a while, which up until 1993 was governed by a communist regime. Around 2000 it was still law that in order to get maps on a 1:10000 scale you needed a government license/permit and could only be bought at the "Mapping Authority". 1:100000 maps on the other hand were available everywhere.
Lots of other countries have restrictions for instance on key bridges and other infrastructure, disallowing access, pictures, stopping, etc.
Historically maps have been closely guarded military secrets. As late as the Renaissance possession of the wrong map could get you executed by European powers, even in peacetime. Rudyard Kipling's novel Kim is largely based on the true story of British surveying and map making in India and central Asia.
AFAIK, military maps are still secret in most places. This is because they contain information that cannot be easily derived from hi-res satellite imagery. Stuff like "how much weight can this bridge support", "how deep is this ford", etc. This is important if you are trying to, say, drive tanks through unfamiliar terrain.
Both Google Maps and Nokia OVI work perfectly fine on my E71 here in China. I guess they just get that encryption library linked inside so the position of my locations always match the roads and buildings on the map. On the other hand, the satellite images in Google Maps do have an offset, which means Google has not redraw the satellite images. Either because Google is unwilling to do that, or, as machinagod said, they cannot take the encryption library back to their image server to do the recalculation.
Useful information. That explains why I was having so much trouble navigating with mapping software on my Android phone when I visited. Now, I wonder if there's a workaround.
Could it be true also for the some parts of Europe ? When i was in Belgium ( Brugge ) and Germany ( Nürnberg, Berlin ) i used google maps a lot. And i realised some streets, not all, looks longer or shorter than others on the map.
In the USA, map data from the government is public domain. In Europe this is not the case. You have to pay for map data from the government. As a result Google Maps is usually based off 3rd party map data like TeleAtlas, who use things like aerial imagery & guesswork. This can result in not 100% accurate maps, so there can be mistakes and errata like that. That's much more likely than government control.
Generally buying national map data is expensive in europe.
The naming of streets is also quite complex, if the street has been there for 1000years then it's likely that various of layers of government aren't quite in synch with what they are calling it.
so if google maps just uses a free public domain source it might not match what the city council or the post office use
Here's a completely anecdotal, "a friend of a friend.." story, but I think it's a cool yi and you'll enjoy it:
A friend of a friend is a cartographer who works in DC. According to this person, the official subway map of DC distorts the true geography of the city -- and the subway lines -- as much for security purposes as it does graphic design purposes. The red line, in particular, apparently is drawn with a completely bogus path through the city on the maps. The true path of the line goes underneath the national mall and several important government buildings, if this person is to be believed.
Subway "maps" tend to be more like generalized graph diagrams than cartographically accurate maps. After all, you're stuck in a box and your only choice is which node to get off at.
But it wouldn't surprise me if an overlay on a cartographic map was intentionally inaccurate. One time I was in DC a cab driver was trying to get me to my hotel. His GPS went totally nonfunctional when we were in view of the Pentagon.
It would be an interesting research project to ride around subway systems with a data-logging accelerometer (like a smartphone). Integrate acceleration to get velocity, integrate velocity to get relative position, get GPS fixes when the signal is available, and diagram the results.
Underground maps usually don't match the real geography. If you made a "real" map, it would be next to useless since the central stations should be all in one place with lots of empty space around. It's the destination / via station you care about when you know the destination, not realistic detail of the path itself.
http://en.wikipedia.org/wiki/Tube_map has some examples of more realistic London underground maps (older editions). It's a common topic of graphic design / visualisation courses.
The red line does turn south a bit going west out of Gallery Place, but it doesn't go any further south than D street and doesn't go under any important federal buildings.
Besides, what would be the point? The National Mall is absolutely riddled with tunnels! West to east there's an old streetcar tunnel at 14th Street under the Bureau of Engraving, the 12th and 9th street road tunnels open to trucks, two tunnels apiece for the yellow/green and orange/blue lines with the latter going under dozens of federal buildings, the entire Smithsonian subway station, large underground art galleries south of the Smithsonian castle, the buried watercourses of Tiber Creek, the National Gallery gift shop & cafeteria under 4th street, the I-395 Center Leg Freeway that has the DOL built on top of it, the United States Capitol subway system, the old C Street streetcar tunnel under Senate Park, and the First Street heavy rail tunnel under the LOC / Supreme Court.
Which official map - the one posted in each station and online? Sure it's distorted: it has to make sense to millions of tourists. Most transit maps I've seen are the same: geographic realism is sacrificed to make it easier for patrons to get around.
Orange and Blue lines go under the Mall: this is reflected on the map. IIRC there is one stop at the Mall, several close. There aren't any Red line stops near the Mall.
several important government buildings
It's D.C. You can't shake a stick without hitting an important government building.
Many people will know about this projection (and first have heard about different projections in general) from The West Wing episode Somebody’s Going to Emergency, Somebody’s Going to Jail (http://en.wikipedia.org/wiki/Somebody%27s_Going_to_Emergency...).
How maps look like depend on a whole bunch of other factors like the projection they use etc. Thus simply overlaying the maps and say, hey, this is distorted, is simply unfounded. It's very likely that Google maps etc may be adopting different projection systems so the users can have smooth using experience zooming in and out, and panning across the global without feeling the earth is round.
A map projection issue could a) easily be fixed, and b) would have been noticed and fixed already, as it would manifest in more places than just china.
Secondly - I lived in Beijing for half a year in 2010 (ie. 2 years after this post was published). I used Google Maps often on my smartphone, and the GPS fix on the features map was incorrect (ie. I would be standing at a street corner and it would show me a few hundred meters down the street on the map).
It starts with a street view. If you zoom in a little, turns out the bar is out in the water! When you switch to Satellite view, the bar is where it is supposed to be, on the shore.
I don't see the anomaly you're talking about. At any rate, it was probably just that -- an anomaly in the mapping software -- which is completely different from the government-mandated misinformation that is the subject of this story.
I've been in Beijing for the past 3 months, and I've been relying solely on Google Maps to get around. I never had one single problem. If there ever was any discrepancy between maps and the real world, I didn't see it.
I don't doubt there are issues, but in Beijing I haven't seen them.
I did see exactly the same thing in Toronto for some time. The satellite image was misaligned with the street map for the Jane/Finch area. It's fixed now.
I do wonder how much trouble Google goes to fix up maps in China. I can't really see enough of the map to tell if this appears to be deliberate distortion, or just another error.
Hopefully Google is still keeping their maps up-to-date... When I was in Beijing, I found the Google map much easier for finding bus routes that the local alternative.
It could simply be a map projection issue - where the traffic data projection is slightly off by an order of 1000 meters. This datum shift could be easily fixed by Google.
[+] [-] machinagod|14 years ago|reply
- The map data is scrambled (GPS coordinates are encrypted). - To correlate a GPS position with the map data, you plug the HW position through an encryption library (which you have to compile in a specific government building in Beijing). - Border drawing is strongly regulated: no border line between Mainland China and Taiwan, Tibet is of course China, South East Asia Islands can't have border lines drawn and Kashmir is a big thing also with border lines. - You can't show pure GPS coordinates - You can't include a number or POIs in your map (mostly government buildings/facilities).
As a note, India as a certain degree of insanity as well: You can't export a map. Launching a PND there involved shipping a bunch of map technicians there to actually make sure we never got a map outside of India...
Cheers, R
[+] [-] andrewcooke|14 years ago|reply
what is the advantage of this? couldn't an attacker get a copy of the software? is there some kind of real-time authorisation step so that they can disable the transformation or change it?
[edit: thanks; wasn't thinking you thought it a good idea, just curious for more info]
[+] [-] Luc|14 years ago|reply
[+] [-] yaix|14 years ago|reply
[+] [-] est|14 years ago|reply
Do you guys put Tibet as disputed area on like 90% of the maps in the West? Really?
[+] [-] danbmil99|14 years ago|reply
I'm sure there are thousands of Chinese engineers with careers transforming map coordinates. You don't want to put these people out of a job, do you?
Humans are funny.
[+] [-] marshray|14 years ago|reply
"There's China" I said. "And there's Taiwan."
"You know Taiwan is really not that big." she said.
"What do you mean?"
"Map makers show it larger than it really is in order to exaggerate its importance."
I was a little weirded out by that idea. This girl was pretty intelligent, she seemed to know some math and logical thinking. She was in the process of becoming a CPA.
For better or worse I responded with practical analysis: "How would that even work? You and I could go buy maps right now for navigating ships and airplanes, those would have to be accurate in order to function. We could compare them to this one and if they are noticeably different we could complain and the company that made the map would lose face. Why would Rand-McNally give a shit about the political importance of Taiwan anyway, enough to risk their own credibility?"
"They just do. All map makers do this." She would not be convinced.
[+] [-] rmc|14 years ago|reply
The most common form of map, Mercator projection, greatly distorts the area of land around the equator, and makes northernly (& southerly) lands appear much larger. It makes Canada, Greenland, Alaska, et al. appear quite large compared to Africa & South America. But those areas are much larger.
http://en.wikipedia.org/wiki/Mercator_projection#Uses
[+] [-] ljf|14 years ago|reply
http://noisydecentgraphics.typepad.com/design/2008/07/this-i...
[+] [-] narkee|14 years ago|reply
I don't think it's unreasonable to think that China is manipulating its map data, particularly when other people here in the mapping industry have already said this is well known in their field.
[+] [-] orijing|14 years ago|reply
You knew her disposition. (You were her friend). What was the goal of that comment, to incent a fruitless political discussion?
Edit: Whoa there. Why the downvotes? I am genuinely curious why the parent decided it was a good idea to stoke that discussion. I have friends whose political views are far from mine, and there are just DMZ topics that I don't dare bring up. For example, a discussion about the Federal Reserve and Operation Twist would be fruitless with my Libertarian friends, who just have a different opinion on that, which I believe is irreconcilable. I would say that's the same situation with Taiwan-strait politics.
[+] [-] john_horton|14 years ago|reply
[+] [-] pyre|14 years ago|reply
[+] [-] rmc|14 years ago|reply
http://sautter.com/map/?zoom=15&lat=31.21741&lon=121...
You can see the noticable difference in street geometry.
[+] [-] fs111|14 years ago|reply
[edit] BTW: India is similar, they are not scrambling the map, but it cannot leave the country either. So as a map-maker you have to have a local company there in order to do business.
[+] [-] iloveponies|14 years ago|reply
[+] [-] joelhaasnoot|14 years ago|reply
[+] [-] jackfoxy|14 years ago|reply
[+] [-] azov|14 years ago|reply
[+] [-] vgrichina|14 years ago|reply
[+] [-] iloveponies|14 years ago|reply
[+] [-] paxswill|14 years ago|reply
[0] http://wiki.openstreetmap.org/wiki/WikiProject_China#Legalit...
[+] [-] wangweij|14 years ago|reply
[+] [-] ArchD|14 years ago|reply
[+] [-] devmach|14 years ago|reply
[+] [-] rmc|14 years ago|reply
[+] [-] nobody31|14 years ago|reply
The naming of streets is also quite complex, if the street has been there for 1000years then it's likely that various of layers of government aren't quite in synch with what they are calling it.
so if google maps just uses a free public domain source it might not match what the city council or the post office use
[+] [-] eob|14 years ago|reply
A friend of a friend is a cartographer who works in DC. According to this person, the official subway map of DC distorts the true geography of the city -- and the subway lines -- as much for security purposes as it does graphic design purposes. The red line, in particular, apparently is drawn with a completely bogus path through the city on the maps. The true path of the line goes underneath the national mall and several important government buildings, if this person is to be believed.
[+] [-] marshray|14 years ago|reply
But it wouldn't surprise me if an overlay on a cartographic map was intentionally inaccurate. One time I was in DC a cab driver was trying to get me to my hotel. His GPS went totally nonfunctional when we were in view of the Pentagon.
It would be an interesting research project to ride around subway systems with a data-logging accelerometer (like a smartphone). Integrate acceleration to get velocity, integrate velocity to get relative position, get GPS fixes when the signal is available, and diagram the results.
[+] [-] viraptor|14 years ago|reply
http://en.wikipedia.org/wiki/Tube_map has some examples of more realistic London underground maps (older editions). It's a common topic of graphic design / visualisation courses.
[+] [-] blasdel|14 years ago|reply
The red line does turn south a bit going west out of Gallery Place, but it doesn't go any further south than D street and doesn't go under any important federal buildings.
Besides, what would be the point? The National Mall is absolutely riddled with tunnels! West to east there's an old streetcar tunnel at 14th Street under the Bureau of Engraving, the 12th and 9th street road tunnels open to trucks, two tunnels apiece for the yellow/green and orange/blue lines with the latter going under dozens of federal buildings, the entire Smithsonian subway station, large underground art galleries south of the Smithsonian castle, the buried watercourses of Tiber Creek, the National Gallery gift shop & cafeteria under 4th street, the I-395 Center Leg Freeway that has the DOL built on top of it, the United States Capitol subway system, the old C Street streetcar tunnel under Senate Park, and the First Street heavy rail tunnel under the LOC / Supreme Court.
[+] [-] bdunbar|14 years ago|reply
Orange and Blue lines go under the Mall: this is reflected on the map. IIRC there is one stop at the Mall, several close. There aren't any Red line stops near the Mall.
several important government buildings
It's D.C. You can't shake a stick without hitting an important government building.
[+] [-] DizzyDoo|14 years ago|reply
http://www.petersmap.com/
[+] [-] ugh|14 years ago|reply
[+] [-] nkassis|14 years ago|reply
[+] [-] yvolution|14 years ago|reply
http://en.wikipedia.org/wiki/Map_projection
[+] [-] srl|14 years ago|reply
[+] [-] sunyc|14 years ago|reply
it is a non uniformed transformation.being applied to.whole map , to lower the accruacy.
[+] [-] ctl51|14 years ago|reply
Secondly - I lived in Beijing for half a year in 2010 (ie. 2 years after this post was published). I used Google Maps often on my smartphone, and the GPS fix on the features map was incorrect (ie. I would be standing at a street corner and it would show me a few hundred meters down the street on the map).
[+] [-] bahman2000|14 years ago|reply
take a look at this POI on 4sq: http://4sq.com/rArZMj
It starts with a street view. If you zoom in a little, turns out the bar is out in the water! When you switch to Satellite view, the bar is where it is supposed to be, on the shore.
[+] [-] nate_meurer|14 years ago|reply
[+] [-] asmosoinio|14 years ago|reply
[+] [-] zrgiu_|14 years ago|reply
I don't doubt there are issues, but in Beijing I haven't seen them.
[+] [-] jann|14 years ago|reply
If you switch between map and satellite mode here, you have a distance of about 390m between the location in both maps.
http://maps.google.com/maps?q=34.25977,108.946309&num=1&...
[+] [-] cleaver|14 years ago|reply
I do wonder how much trouble Google goes to fix up maps in China. I can't really see enough of the map to tell if this appears to be deliberate distortion, or just another error.
Hopefully Google is still keeping their maps up-to-date... When I was in Beijing, I found the Google map much easier for finding bus routes that the local alternative.
[+] [-] mapster|14 years ago|reply
[+] [-] srl|14 years ago|reply