
All Maps in China are Transformed - jann
http://home.wangjianshuo.com/archives/20081109_all_maps_in_china_are_transformed.htm
======
machinagod
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...

Cheers, R

~~~
yaix
Everywhere in China you can buy illlegally imported smartphones (cheaper,
avoids chinese sales taxes) from Hongkong, all with GPS included.

~~~
jrockway
One country, two systems.

------
marshray
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.

~~~
rmc
_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.

<http://en.wikipedia.org/wiki/Mercator_projection#Uses>

~~~
alexqgb
The Mercator projection isn't a good example of a map in which visual
distortion and a lack of navigational utility go hand in hand.

Indeed, the hole point of the projection was to make navigation easier by
allowing rhumb lines (the shortest distances between two points on a curved
surface) to be charted as perfectly straight lines on a two-dimensional map.
From these lines of constant bearing, mariners could work out the precise -
and constant - angle they should maintain in relation to the pole star in
order to get from one point to another.

Without a reliable method for establishing longitude at sea, 17th Century
navigators could never be exactly sure how far along their courses they were,
but at least they could know that they were heading in the right direction.
Given the level of uncertainty involved in these enterprises, this one piece
of (relatively) hard and verifiable data was extraordinarily important, making
the accuracy of the projection, and the mathematically - if not visually -
correct placement of shorelines within it especially important.

Unfortunately, the iconic value of the Mercator projection has vastly outlived
its utility - or at least, the common awareness of the once formidable
navigational problems it addressed. Far from seeing it as a brilliant
technical solution, it is often seen through a purely political filter that
views its strengths as weaknesses, while completely missing the map's actual
intent.

~~~
Sniffnoy
Let's not get mixed up about what the projection did and didn't do. As you
point out, the importance of rhumb lines comes not from the fact that the
thing they keep constant -- the bearing (with respect to north/south) -- was
something that could actually be measured.

Rhumb lines are not, however, the shortest distance between two points on a
sphere. Those would be great circles. In particular, note that along a rhumb
line one can never reach the north or south pole. Indeed, rhumb lines are
dependent on your choice of poles, which the actual shortest course clearly
cannot be!

~~~
Sniffnoy
Argh. Misnegation from earlier version. "As you point out, the importance of
rhumb lines comes from the fact that..." -- there shouldnt' be a not there.

~~~
pekk
You are (it seems intentionally) ignoring the point that Mercator's area
distortion doesn't dangerously mislead in navigation, quite the contrary. Or,
if that isn't true, please name some cases where navigators were messed up
because they thought Greenland looked bigger than it was in area.

Unless you use a globe, every projection onto a flat rectangular surface
distorts.

Now how does that make more plausible the claim that world map makers are
inflating the area of Taiwan on purpose?

~~~
alexqgb
Really? Seemed like he was simply pointing out an error on my part. Don't see
where Taiwan enters that at all.

More to the point, there's a big difference between distorting scale in a way
that's mathematically consistent throughout the projection (i.e. one in which
you preserve shape or position at scale's expense), and simply fudging the
scale in a particular spot.

------
john_horton
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.

~~~
pyre
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.

------
rmc
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:

[http://sautter.com/map/?zoom=15&lat=31.21741&lon=121...](http://sautter.com/map/?zoom=15&lat=31.21741&lon=121.4504&layers=B000000TFFFFFTFF)

You can see the noticable difference in street geometry.

------
fs111
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.

~~~
iloveponies
It's news to the rest of us who don't work in that world.

~~~
FuzzyDunlop
Requiring legitimate incorporation in a foreign country in order to do
business there (typically through partnership with a domestic firm) is also
not unique to China or map making.

~~~
nate_meurer
No, but doing so in order to ensure state control of information for
propaganda purposes is certainly a feature of tyrannical governments, China
being a particularly strong example.

------
jackfoxy
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.

~~~
azov
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.

~~~
tomjen3
But the thing is that most bridges which has a weight limit on them has that
limit on a sign next to them.

And if you want to know the depth of a ford, well you can go and measure it.

So I really don't get why they would make them secret.

~~~
bdunbar
_So I really don't get why they would make them secret._

It's helpful to know the ford depths of a river crossing before you get there
with your tanks.

Take a fanciful example. One could not, say, send a U.S. Army survey team to
measure the depth of the Orne before the allies landed in Normandy. The
Germans would really object to that kind of thing.

~~~
tomjen3
Properly not with tanks. But one old guy with a fishing pole in a boat?

~~~
bdunbar
We're getting into 'what-if' territory.

------
vgrichina
It isn't surprising at all.Soviet Union maps were also intentionally
inaccurate. This inaccuracy still often appears in xUSSR maps.

------
iloveponies
Is OpenStreetMaps blocked in China? If not, there could be huge precedence to
subvert this.

~~~
paxswill
OSM is banned in China [0].

[0]
[http://wiki.openstreetmap.org/wiki/WikiProject_China#Legalit...](http://wiki.openstreetmap.org/wiki/WikiProject_China#Legality)

~~~
felipe
I developed a project in China using OSM and it's certainly not blocked there
(i. e.: The host is accessible).

The problem of OSM in China is its limited data-set. For example, in the city
I developed the project OSM had only the major streets, and the map was quite
old.

~~~
jann
Probably because private mapping is prohibited and there is no public-domain
map data.

from paxswill's link:

"According to the Surveying and Mapping Law of the People's Republic of China,
private surveying and mapping activities are illegal in mainland China."[0]

[0][http://wiki.openstreetmap.org/wiki/WikiProject_China#Legalit...](http://wiki.openstreetmap.org/wiki/WikiProject_China#Legality)

~~~
rmc
_no public-domain map data_

For the record there is no public domain map data in a lot of countries in
Europe. The USA has the sensible approach of 'all government data (incl. maps)
should be public domain'. In Europe the state owned mapping organisations do
the mapping and claim full copyright on the maps & data.

The 'illegal to make your own maps' is, obviously, not the case in EU

~~~
iliis
> _In Europe the state owned mapping organisations do the mapping and claim
> full copyright on the maps & data._

This is true here in Switzerland. You have to pay quite a bit for our maps. I
think it's a good thing actually, because their quality is worth the price.
They provide extreme detail even in very remote locations (well, remote for us
at least ;)). And for doing quick lookups, there's a free online-map at
<http://map.geo.admin.ch/>, which also provides a lot of statistical data.

~~~
rmc
Yep. OSM was set up by some people from the UK and the OS knows the location
of everything that's more than about 20cm big and nailed down (from planning
applications & surveying), so they have lots of high quality data.

However most people/businesses don't need that.

Just look at Google maps & OpenStreetMap. They don't have submetre accuracy,
however there are still quite useful to people and businesses.

------
wangweij
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.

------
ArchD
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.

------
devmach
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.

~~~
rmc
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.

------
eob
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.

~~~
marshray
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.

~~~
georgieporgie
_His GPS went totally nonfunctional when we were in view of the Pentagon._

Which is pretty humorous since, once you're vaguely close to it, it's hard not
to find it. If they built several other pentagonal buildings in the area, it
would be a different story. :-)

~~~
Game_Ender
They might have some local GPS jammers to make it harder for unmanned drones
or bombs to navigate near the building.

------
DizzyDoo
This reminds me of the Peters Projection, one of the weirder attempts to map
the oblate spheroid nature of the earth to a 2D plane.

<http://www.petersmap.com/>

~~~
nkassis
Wow, it would definitively be hard to use such a map in Canada looking at how
it squeeze the polls.

~~~
biot
Though politicians would love to squeeze the polls during an election.

------
yvolution
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.

<http://en.wikipedia.org/wiki/Map_projection>

~~~
srl
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.

------
sunyc
of course it is china only. in china licensed gps maker can buy a chip deal
with the offset ,provided by government.

it is a non uniformed transformation.being applied to.whole map , to lower the
accruacy.

------
ctl51
First - that post is 3 years old.

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
i don't think it's unique to China

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
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.

------
zrgiu_
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.

~~~
jann
It's generally not by much, but when you're relying on google maps to get
exact coordinates, you might get into trouble.

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&...](http://maps.google.com/maps?q=34.25977,108.946309&num=1&vpsrc=0&ie=UTF8&t=m&z=15)

~~~
gbog
Yes and there is a fix in a cyanogen modded version.

------
cleaver
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.

------
mapster
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.

~~~
srl
A map projection issue would show up in other places on the map, and would
have been fixed by now.

~~~
mapster
Not true at all. Data can be pulled from multiple database sources, each with
their own projection info., so if there are datum shifting issues, you can
have some pieces not aligning to basemap while others do.

------
kleim
This is so ridiculous. China really thinks US Army is using Google maps? I
wonder how they did not figured out that all armies are not working like
theirs...

------
languagehacker
This really made me pine for the following feature Google will have in five
years: "It looks like this was written in English by a non-native speaker.
Would you like us to make this more grammatical? (Yes) (No)"

------
bigwally
The Yahoo Maps for China don't look very transformed.

[http://maps.yahoo.com/#lat=39.8908713496569&lon=116.4246...](http://maps.yahoo.com/#lat=39.8908713496569&lon=116.4246940612793&zoom=15&mvt=h&trf=1)

(This isn't a vote for Yahoo Maps, just an observation)

------
bigwally
This is not a problem with using a GPS, the problem is the shift from using
different mapping technologies.

Trying to get satellite and the map portions to line up is very difficult.
Trying to do it on a global scale with data from multiple sources... you get
the idea.

Now please get back to China bashing and don't let the facts get in the way of
your political/religious feelings. Remember to include lots anecdotal evidence
and use the word red. And as always bring up other countries that seem scary
on fox news.

~~~
tompagenet2
While I understand your cynicism, my experience in Shanghai and Beijing
suggests that Google Maps are some way off between satellite and streetmap
modes. I have not found the same problem (or at least to anywhere near the
same level) in the UK, Chicago, Michigan, Korea, Japan, Germany, Slovakia and
many other countries. There does seem to be an offset applied.

An example in Shanghai: <http://g.co/maps/m34n8> An example in Seoul:
<http://g.co/maps/4gk3t>

Note the near perfect alignment in the latter, and way-off alignment in the
former.

~~~
yvolution
No where else has more sky scrapers than Shanghai and Beijing, which easily
affects your GPS signal.

~~~
cbr
If you mean buildings over 100m, then no:

    
    
        1 	Hong Kong
        2 	New York City
        3 	Tokyo
        4 	Dubai
        5 	Shanghai
    

Beijing is #20.

[http://en.wikipedia.org/wiki/List_of_cities_with_most_skyscr...](http://en.wikipedia.org/wiki/List_of_cities_with_most_skyscrapers)

