OpenStreetMap contemplates licensing

By Jonathan Corbet
October 22, 2008

Maps are cool; there's no end of applications which can make good use of mapping data. There is plenty of map data around, but it's almost exclusively proprietary in nature. That makes this data hard to use with free applications; it's also inherently annoying. We, as taxpayers, own those streets; why should we have to pay somebody else to know where the streets are?

Your editor likes to grumble about such things; meanwhile, the OpenStreetMap project (OSM) is busily doing something about it. OSM has put together a database and a set of tools making it easy for anybody to enter location data with the intent of producing a free mapping database with global coverage. It is an ambitious project, to say the least, but it's working:

Right now on each and every day, 25,000km of roads gets added to the OpenStreetMap database, on the historical trend that will be over 200,000km per day by the end of 2009. And that doesn't include all the other data that makes OpenStreetMap the richest dataset available online.

OSM data is not limited to roads; just about any point or track of interest can be added to the database. If current trends continue, OSM could well grow into the most extensive geolocation database anywhere - free or proprietary. And those trends could well continue; one of the nice aspects of this kind of project is that no particular expertise is needed to contribute. All you need is a GPS receiver and some time; some OSM local groups have even acquired a set of receivers to lend out to interested volunteers. This is our planet, and we can all help to map it.

All this work raises an interesting question, though: under what license should this accumulated data be distributed? Currently, the OSM database is covered by the Creative Commons Attribution-ShareAlike 2.0 license. It is a copyleft-style license, requiring that derived products be made available under the same license. So, for example, if a GPS navigator manufacturer were to include an enhanced version of the OSM database in its products, it would have to release the enhanced version under the CC by-SA license.

The OSM project is not happy with this license, though, and is looking to make a change. The attribution requirement is ambiguous in this context; do users need to credit every OSM contributor? Does making a plot of OSM data with added data layered on top create a derived product? But the scariest question is a different one: can the CC by-SA license cover the OSM database at all?

Copyright law covers creative expression, not facts. The information in the OSM database is almost entirely factual in nature; one cannot copyright the location of a street corner. So what OSM is trying to protect is not the individual locations, but the database as a whole. Copyright law does allow for the protection of databases, but that law is far more complex than the law for pure creative works, and it varies far more between jurisdictions. Europe has a specific (though much-derided) database right, the US has far weaker database protections, and other parts of the planet lack this protection altogether. So it may well be that, if some evil corporation decides to appropriate the OSM database for its own nefarious, proprietary purposes, there will be nothing that the OSM project can do about it.

So the project is thinking of making a switch to the Open Database License (ODbL), which is still being developed. It, too, is a copyleft-style license, but it is crafted to make use of whatever database protection is available in a given jurisdiction. To that end, the ODbL is explicitly structured as a contract between the database owner and the user. In any jurisdiction where database rights are not recognized under copyright law, the contractual nature of the ODbL should provide a legal basis to go after license violators.

But the use of contract law muddies the water considerably; there are good reasons why free software licenses are carefully written to avoid that path. Contracts are only valid if they are explicitly and voluntarily entered into by all parties. If the OSM cannot show that a license violator agreed to abide by the license, it has no case under contract law. The project has a plan to address this problem:

To ensure that potential users are aware of and agree to the contract terms, we are proposing to require a click-through agreement before downloading data. (All registered users would agree to this on signing up so will not need a further click-through on each download.)

Registration and clickthrough licensing are obnoxious, to say the least. But, in any case, the only people who will go through that process are those who obtain the database directly from OpenStreetMap. The ODbL allows redistribution, naturally, and it does not require that explicit agreement be obtained from recipients of the database. So it is hard to see an outcome where copies of the database lacking a "signed" contract do not proliferate. Additionally, reliance on contract law makes it very hard to get injunctive relief, weakening any enforcement efforts considerably.

The ODbL includes an anti-DRM measure; if a vendor locks down a copy of the database with some sort of DRM scheme, that vendor must also make an unrestricted copy available. This license tries to distinguish between "collective databases" (which are not derived works) and "derivative databases" (which are). Drawing layers on top of an OSM-based map is a collective work; tracing lines from such a map is a derivative work. It is, in general, a complex bit of work.

It is complex enough that a number of OSM contributors are wondering if it's all worth it. Jordan Hatcher is one of the authors of the ODbL, and he supports its use with OSM, but even he understands the concerns that some people have:

The [Science Commons] point is that all this sort of stuff can be a real pain, and isn't what you are really doing is wanting to create and manipulate factual data? Why spend all the time on this when the innovation happens in what you can do with the data, and not with trying to protect the data in the first place.

There is an active group with OSM which is opposed to this kind of licensing and would, in fact, rather just get down to the task of collecting and distributing the data. They express themselves in terms like this:

One thing I really love about OSM is the pragmatic, un-political approach: You don't give us your data, fine, then we create our own and you can shove it.

Not: You don't give us your data, fine, then we create a complex legal licensing framework that will ultimately get you bogged down in so many requests by prospective users who would like to use our data and yours but cannot and you will sooner or later have to release your data according to the terms we dictate and then we will have won and the world will be a better place.

These contributors would rather that OSM release its data into the public domain - or something very close to that. Rather than put together a complicated license, they prefer to just publish their data for anybody to use as they see fit. There have been all of the usual discussions which resemble any "GPL vs. BSD" licensing flame war one has ever seen - except that the OSM folks appear to be a very polite crowd. It comes down to the usual question: will the OSM database become more complete and useful if those who extend it are forced to contribute back their changes?

The public domain contingent clearly does not believe that any improvements to the database obtained via licensing constraints will be worth the trouble. So it seems likely that there will be some sort of fork involving the creation of a smaller, purely public-domain OSM database. It may well be an in-house fork, with the public domain data being merged into the larger, more restrictively licensed database for distribution. Regardless of how that goes, this split raises issues of its own: how are the two databases to be kept distinct in the face of cooperative additions and edits?

Any relicensing of the database also brings up another interesting question: what to do about all of the existing data, which may or may not be copyrighted by those who contributed or edited it? The license change may well require a process of getting assent from all contributors and purging data obtained from those who do not agree. This proposed timeline shows how the project is thinking about working through this task. It is hard to imagine this process going entirely smoothly.

The OSM community clearly has a set of thorny issues to work out. Given that, it's not surprising that this process has already been dragged out over the better part of a year. How this issue is eventually resolved will certainly serve as an example - not necessarily a good example - for other projects working on free compilations of factual data. Let us hope that OSM can come to a solution which lets this project continue to grow and generate a valuable database that we all will benefit from.

to post comments

OpenStreetMap contemplates licensing

Posted Oct 22, 2008 17:37 UTC (Wed) by xav (guest, #18536) [Link] (1 responses)

About ODbL:
"it is crafted to make use of whatever database protection is available in a given distribution"
s/distribution/juridiction/ ?

Jurisdiction

Posted Oct 22, 2008 18:02 UTC (Wed) by corbet (editor, #1) [Link]

Yes, obviously. Fixed now.

OpenStreetMap contemplates licensing

Posted Oct 22, 2008 17:51 UTC (Wed) by erwaelde (subscriber, #34976) [Link]

"One thing I really love about OSM is the pragmatic, un-political approach: You don't give us your data, fine, then we create our own and you can shove it."

That sums it up for me. I do contribute bits from my little world and I'm very grateful to all the others who contribute theirs. Thanks!

Erich

OpenStreetMap contemplates licensing

Posted Oct 22, 2008 17:56 UTC (Wed) by rvfh (guest, #31018) [Link] (2 responses)

How did Wikipedia solve the issue? Same problem isn't it?

OpenStreetMap contemplates licensing

Posted Oct 22, 2008 18:24 UTC (Wed) by rfunk (subscriber, #4054) [Link] (1 responses)

It appears that Wikipedia chose the GNU Free Documentation License. But no, it's not the same problem. They're copyrighting an expression of (hopefully) facts as written in articles by contributors, not a collection of raw facts.

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 10:10 UTC (Thu) by lysse (guest, #3190) [Link]

Not necessarily facts at all, in some cases. They're definitely covered by copyright. ;)

Legal vs. technical content at LWN

Posted Oct 22, 2008 19:39 UTC (Wed) by asamardzic (guest, #27161) [Link] (1 responses)

I'd like to state first that I'm well aware on importance of the legal stuff, especially on importance on learning about this stuff in a community consisting mostly of technical people. However, I'm also wondering is it really needed to go in such detail, like in above article, here at LWN? I have an impression that recently weekly editions (I guess this article will appear tomorrow in weekly edition) very often have a lengthy article on minutious details of particular licensing case on its front page. While I try to read these with interest too, must confess I'd much more like to read about technical stuff, for example in this particular case about how to contribute road data to OpenStreetMap, then about software or devices already using this database, and alike stuff...

Legal vs. technical content at LWN

Posted Oct 23, 2008 0:55 UTC (Thu) by JoeBuck (subscriber, #2330) [Link]

I suggest just skipping the content that you aren't interested in. Like it or not, these issues do matter; it's OK if you don't care, but many do.

OpenStreetMap contemplates licensing

Posted Oct 22, 2008 20:11 UTC (Wed) by adegeus (guest, #22055) [Link] (1 responses)

Why not just make OSM "public domain", so no license would be required at all. Then we, "the world". would really own our own map, and anybody can do anything with it he or she likes. E.g. also put it in to a propreitary box.

OpenStreetMap contemplates licensing

Posted Oct 24, 2008 16:01 UTC (Fri) by giraffedata (guest, #1954) [Link]

Why not just make OSM "public domain", so no license would be required at all?

A significant part of the article covered that question. It's the same question as why don't we put the Linux kernel in the public domain: The idea is that copyright is valuable property and rather than give it away completely, the owners can trade it for other people giving up some of their copyright. E.g. if I let you distribute my map layer, you have to let everyone distribute yours.

According to the article, some people believe in this with respect to OSM and others believe there's not enough out there to trade for, so it's just not worth the legal trouble.

There are yet another side to all this

Posted Oct 22, 2008 20:47 UTC (Wed) by khim (subscriber, #9252) [Link] (22 responses)

In Russia or China, for example, posession of the OpenStreetMap on your laptop can bring you to a jail (probably not right now as maps of Russian are pretty rudimentary in OSM). What can be done (if anything) about that?

In other news...

Posted Oct 22, 2008 22:33 UTC (Wed) by denf (guest, #23577) [Link] (1 responses)

... in some countries, possession of marijuana can bring you to jail. What
can be done about that?

On a serious note, I believe this is not the case anymore. With GLONASS
being pushed to public use accurate maps have to be legal in Russia.

Posession? No. Mapmaking? Yes.

Posted Oct 23, 2008 5:17 UTC (Thu) by khim (subscriber, #9252) [Link]

If the map has proper licenses it's not illegal anymore. But if you did it yourself and included wrong type of information... treason is not an easy charge to repell.

There are yet another side to all this

Posted Oct 23, 2008 2:23 UTC (Thu) by clugstj (subscriber, #4020) [Link]

Uhh, nothing. Data and licenses/contract cannot correct governments.

There are yet another side to all this

Posted Oct 23, 2008 2:40 UTC (Thu) by flewellyn (subscriber, #5047) [Link] (14 responses)

I'm a bit confused...why would possession of a street map be a jailable offense in any jurisdiction?

There are yet another side to all this

Posted Oct 23, 2008 3:56 UTC (Thu) by felixfix (subscriber, #242) [Link] (10 responses)

Military secrets. It is a widespread rumor that maps in the Soviet Union were illegal for civilians, and it certainly seems plausible. Britain in WW II took down or misdirected road signs in rural areas to make it that much harder for German invaders to find their way around.

There are yet another side to all this

Posted Oct 23, 2008 3:57 UTC (Thu) by flewellyn (subscriber, #5047) [Link] (4 responses)

Sure, but in this age of satellite imaging and global information networks, how well would such measures actually work?

There are yet another side to all this

Posted Oct 23, 2008 4:24 UTC (Thu) by felixfix (subscriber, #242) [Link]

In this age of global information networks, how well does censorship work?

Why you would expect any dictatorship to be modern and up to date in their thinking is beyond me.

Not very well at all - it does not mean you'll not be jailed

Posted Oct 23, 2008 5:26 UTC (Thu) by khim (subscriber, #9252) [Link] (2 responses)

Compare this and this. Note: both maps contain kind of "black hole" in the middle of the town. Sure: it's some kind of top-sikrit object. I'm pretty sure appropriate Google search reveal which object exactly - but it does not mean you'll not be jailed for possesion of map of that object.

It does not work as military precaution but it works very well indeded if you want to punish someone :-)

404 - black hole not found...

Posted Oct 27, 2008 14:54 UTC (Mon) by hummassa (guest, #307) [Link] (1 responses)

I think your tup-sikrit installation is not a lot tup-sikrit anymore, because I can't see any black holes, not in Google Maps, and not in Yandex...

Stange - I can see it clearly.

Posted Oct 27, 2008 18:15 UTC (Mon) by khim (subscriber, #9252) [Link]

Have you really expected BLACK hole? Oh, silly me. It's GRAY. Big difference there. See "ulitsa Tihonravova"? See buildings across the street? On other side - there are numbers 28,30,32,36,38/2, 40, 42. On the other side... On satellite there are over 20 building of different sizes. On the map... nothing. Huge gray blob. WHY these buildings are not marked? Yup: that's top-sikrit object in question. MCC to be exact.

Just like another example it's pointless and stupid. Yet it's law.

There are yet another side to all this

Posted Oct 23, 2008 5:18 UTC (Thu) by afalko (guest, #37028) [Link] (1 responses)

Correct me if I am wrong, but I would assume that maps of all sorts were legal in the USSR, except to be considered fact they would have to be made and authorized by the state. If you happened to make a map of a military secret, you'd probably vanish into thin air at the hands of the KGB, but that is a different matter.

Today in Russia, I would except you to be allowed to use OSM and OSM's license would likely be enforced to the furthest extends of the law (which IMO would not be a great extent). However, you probably will get in deep trouble if you submit gps mappings containing perceived military secrets.

If you use openssh in Russia, then legally you are committing a crime, as you are not allowed to use encryption tools without permission from the government. Once again, it comes down to enforcement. From what I know, just about every corporation in Russia skimps on taxes. The government does not really care much unless you get out of line, in which case you're going to find yourself behind bars for the tax evasion everyone commits.

Anyway, back on topic, you should be OK submitting maps to OSM in Russia, but just don't start submitting GPS mappings of your attempts to find Nuclear warheads :).

It's not legal to OWN map - it's illegal to CREATE map

Posted Oct 23, 2008 8:23 UTC (Thu) by khim (subscriber, #9252) [Link]

Map ownership is not restricted. Map creation is. It's kinda hard to point to someone who owns the license (granted by Russian government) for OSM... All other maps (especially printed ones but also Google Maps or Yandex Maps) have pointer to someone who owns the license.

That being said I'm pretty sure induvidual users will not be jailed, but Linux distributors who include OMS data on the CD... that's another question altogether :-)

There are yet another side to all this

Posted Oct 23, 2008 10:12 UTC (Thu) by lysse (guest, #3190) [Link] (2 responses)

Although as someone who grew up in a rural area of England, I can attest to that gesture being largely superfluous...

WW II road signs in rural England

Posted Oct 24, 2008 15:49 UTC (Fri) by giraffedata (guest, #1954) [Link] (1 responses)

as someone who grew up in a rural area of England, I can attest to that gesture being largely superfluous...

Superfluous how? It didn't make it harder for Germans to get around, or Germans weren't going to be there?

WW II road signs in rural England

Posted Oct 24, 2008 17:54 UTC (Fri) by Hawke (guest, #6978) [Link]

I would assume the GP was talking about the road signs being useless anyway...

There are yet another side to all this

Posted Oct 24, 2008 11:49 UTC (Fri) by gdt (subscriber, #6284) [Link] (1 responses)

There was a conviction of Faheem Khalid Lodhi in Australia in 2003 for "possessing things connected with terrorist acts". The "thing" was a map of an Australian state's electricity grid. See Regina v Lodhi [2006] NSWSC 691.

Lodhi's map was not a street map, but major transmission links and substations could well appear in OpenStreetMap as they are particularly good reference points in rural areas.

There are yet another side to all this

Posted Oct 24, 2008 14:20 UTC (Fri) by flewellyn (subscriber, #5047) [Link]

Yes, but given the state of race relations in Australia (not much better than the US), I imagine his real crime was being Muslim.

There are yet another side to all this

Posted Jan 17, 2011 12:14 UTC (Mon) by wookey (guest, #5501) [Link]

The greeks are paranoid about maps too, and appear to treat them as weapons. I don't know the actual law, but I do know that high-res maps are pretty-much unobtainium (or were a few years ago), and that you could get into trouble for distributing them (we were cavers that needed a good map - the only way we could even look at one was to find a freindly person at a road-building company who could show us his (but definately _not_ hand it over).

And recall what happened to some UK plane spotters a few years back for a general idea of the paranoia level. http://www.independent.co.uk/news/world/europe/greek-cour...

You can see the remnants of this 'maps are military' meme in the UK, where the mapping agency is still called the 'Ordnance Survey' (ordnance is bombs and missiles). Mapping was once an almost exclusively military activity. A few countries haven't quite got past this to accept that it's incredibly useful for everyone and that military/state control of mapping is no longer possible.

There are yet another side to all this

Posted Oct 23, 2008 8:15 UTC (Thu) by filipjoelsson (guest, #2622) [Link] (1 responses)

To throw in a bone: In Sweden it is still illegal to publish a non-authorized map. The authorization step is a military guy removing any of our mobilization stuff from the map.

Nevermind that it is quite stupid - all you need to do to find military mobilization stuff is to compare aerial photography with recent maps (stuff that's in the photo but not the map tends to stand out) - it's quite illegal anyway. So is photographing from the air (plane or tower) without a permit, btw.

Is it obvious we've spent hundreds of years being afraid of the Russians, or what?

There are yet another side to all this

Posted Oct 24, 2008 18:01 UTC (Fri) by Creideiki (subscriber, #38747) [Link]

Almost correct. SFS 1993:1742 6§ says you're not allowed to distribute aerial photographs or detailed maps without permission. There are only a few areas (see AIP ENR 5 2.2.1, or any TMA map) where photography in itself is forbidden.

Interestingly, SFS 1993:1742 7§ explicitly exempts pure satellite images from the permission requirements. How high resolution are the best satellite images commercially available nowadays?

There are yet another side to all this

Posted Oct 23, 2008 8:27 UTC (Thu) by dottedmag (subscriber, #18590) [Link] (1 responses)

You're disinformed. It is no longer the truth in Russia.

Exaggeration? Yes, but not a big one.

Posted Oct 23, 2008 8:41 UTC (Thu) by khim (subscriber, #9252) [Link]

Heh. That's bisuness model of Geocentre Consulting: they check licenses of firms who offer maps and if they don't have proper licenses - they are going to them and demand to sign an agreement. Alternative is not pretty: high penalty or jail time. You may be true as far as actual jail time is concerned: it gives nothing to extorters so I can not recall any recent cases where it actually happened. But fines are fine :-) They can be used with great "otkat" technology to produce actual money.

So if you are talking about problems for pesonal use - it's probably Ok (too much hassle for too little gain), but shops who'll offer CDs with OSM... that's another story :-)

OpenStreetMap contemplates licensing

Posted Oct 22, 2008 23:00 UTC (Wed) by jengelh (subscriber, #33263) [Link] (1 responses)

What's much more interesting, assuming you had an appropriate license how would you detect proprietary additions? "Look ma, that street corner ain't in OSM, it must be prop!" Happy searching within the number of street corners in the world.

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 0:22 UTC (Thu) by corbet (editor, #1) [Link]

Proprietary additions would probably be completely different types of data. On the list there was a discussion of a city's database of bus stops, for example.

OpenStreetMap contemplates licensing

Posted Oct 22, 2008 23:37 UTC (Wed) by dlang (guest, #313) [Link]

as a community we ridicule the companies that try to protect databases of facts (phone books, etc)

as such I think it's wrong to turn around and try and protect databases of facts that we accumulate (this map data is a very good example)

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 2:09 UTC (Thu) by pj (subscriber, #4506) [Link] (1 responses)

They should put their database into readable english text then use the GFDL on *that* for redistribution. Any machine translation of that is a derivative work, so that's protected via the GFDL as well, by the same logic that translating a .wav into a .mp3 is still protected via the copyright.

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 4:24 UTC (Thu) by butlerm (subscriber, #13312) [Link]

That won't work. The sine qua non of copyright is creativity. A usable machine generated natural language representation of a database of facts would not have this property.

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 4:16 UTC (Thu) by pabs (subscriber, #43278) [Link]

I'd love to see them use CC0 - an enhanced version of a public domain dedication, that includes a license for countries that do not allow living persons to transfer their works to the public domain. It is done by the Creative Commons folks and is under development.

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 4:31 UTC (Thu) by dankamongmen (subscriber, #35141) [Link]

it was my understanding that "sweat-of-the-brow" arguments protected databases whose construction required significant initiative/expense/ingenuity.

wow, cs4001's term paper came in handy. who'd have thought?

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 7:14 UTC (Thu) by ewan (guest, #5533) [Link]

Would it actually be much of a loss if OSM was to lose copyright
protection on the grounds that it's just a big bundle of facts, since any
such decision would surely also destroy the copyright on existing
proprietary mapping databases, and get to the end goal of Free maps that
much quicker?

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 10:53 UTC (Thu) by k3ninho (subscriber, #50375) [Link] (3 responses)

Our Editor's comment about not being able to copyright facts seems a USA issue; the idea seems to me a legal fiction because there are many ways to embody a fact. Consider a map: it is a mapping to paper of a physical layout, and there are a number of known and popular projections when mapping the surface of a planet to flat paper.

I'm unsure about other jurisdictions but, in the UK, Copyright in an original work requires expenditure of more than a trivial degree of independent skill, labour and judgement. In the case preparing the maps for OSM, it's arguable that the skill required in operating the GPS device and converting its recorded information, the labour in travelling the journeys required to make the survey, and the judgement in editing the map data before upload would ensure that the embodiment of information justifies protection by copyright. Does the Berne Convention not mean that these criteria apply internationally?

I believe that copyright subsists in the OSM data. There will further be a database right in EU. Is there an assignment of copyright when you upload map data? If not, that's a slipup. But the real issue is that OSM may take on GIS providers whose datasets are extremely expensive. That will require some clear thinking about how to ensure that the community retains access to their mapping.

OpenStreetMap contemplates licensing

Posted Oct 23, 2008 11:45 UTC (Thu) by spaetz (guest, #32870) [Link] (1 responses)

> Consider a map: it is a mapping to paper of a physical layout, and there are a number of known and popular projections when mapping the surface of a planet to flat paper.

We are not talking about not being able to copyright the map. Of course a map is copyrightable. The choice of colors and other issues makes it an expression of creativity.

The database that contains those "facts" is a different beast though. It is just that: a collection of facts. And copyright does not apply to facts.

Fact & precision ? Multiple contributors ?

Posted Oct 27, 2008 17:29 UTC (Mon) by lacostej (guest, #2760) [Link]

Some ideas that probably mean not much...

How precise need a fact to be so that it becomes a fact ? The GPS positionning is precise up to a certain limit. Plus there are potential issues (hardware, user errors, etc..) that make the data in the database unique.

Think about a group of painters trying to reproduce a landscape, each with different tools. Althought the end result might be very similar to the reality (the facts), it could be slightly different enough to be seen as a creation. Futhermore, as the work is always in progress and uses so many contributors make it a special case. It's not like the creation was directed/controlled and the current result (a sub set of the reality) is some sort of community art. Or do we need changes in the law to manage those community gathered 'facts' ?

Finally: what about using colors to represent the GPS positions ? :) Or losing some precision/introducing small errors voluntarily in order to make the result a creation ?

OpenStreetMap contemplates licensing

Posted Oct 28, 2008 4:43 UTC (Tue) by dvdeug (subscriber, #10998) [Link]

Standards for copyrightability vary around the world. The UK is generally believed to admit copyrights for stuff the US won't. Under US law, a copy of a PD painting, no matter how skillful, laborious or judgement-requiring, does not permit of a new copyright. Likewise, a phonebook doesn't get a copyright, nor does the listing of cable companies. Only creative works get a copyright; and the whole point behind something like this is not a new creative work, it's a recording of the physical facts of the world in a mechanical manner.

Don't even need a GPS receiver

Posted Jan 12, 2011 21:09 UTC (Wed) by Eliot (guest, #19701) [Link]

A minor nit about "All you need is a GPS receiver and some time"?

All you need is a web browser connected to OSM, local knowledge, and some time. Much useful mapping can be done without a GPS by using available satellite imagery and local knowledge.

See http://wiki.openstreetmap.org/wiki/Mapping_techniques#Sat...