I don't think of myself as a luddite in any way, but one can't help but get the feeling that the image of the world brought to us by huge tech companies has gigantic holes in it.
When you spend all of your time inside of that image of the world it's difficult to see the gaps. I love this. It's as if he walked in to a void.
This is more a shift in perception of what online maps are taken for. Online maps were traditionally made for one purpose only, car navigation, not to show a complete picture of the world.
And the only commercially geodata available in digital format, from a few specialized companies, were for car navigation in lucrative markets (like the US and Europe). It wasn't a given that online maps work properly or show more than base coverage outside those regions.
Only recently maps providers started integrating user created content.
OSM as a whole is also surprisingly sparse outside those established markets.
Just a reminder, back in 2007 Mexico wasn't even covered by Google.
Microsoft generously provided the imagery he was using.
(Well, probably. Anyway, big tech companies are doing a lot of the work that goes towards satellite and aerial imagery being easy for people to access. So are governments. It just isn't as clear cut as you stated it.)
Of course, of course. I meant 'image of the world' in the broader sense — sort of like the "OK" from Mr. Penumbra's 24 Hour Bookstore.
I didn't mean to imply that they're purposefully ignoring things, but that it's difficult to create a methodology for mapping the world that doesn't ignore features of it — either by accident or as a rule.
My comment was to agree with the concept that its easy for me to blindly believe in what the big tech companies publish. Mapping or otherwise.
I love Doctor Who episodes where on the surface everything looks normal, but on closer inspection things are very different (eg Weeping Angels or The Silence).
"one can't help but get the feeling that the image of the world brought to us by huge tech companies has gigantic holes in it."
Compared to the image of the world you get from your chair without those tech companies, I wouldn't describe it as 'holes', but as filling in 99% of the white areas.
Columbus didn't create a huge hole in the wolrd's map
> the image of the world brought to us by huge tech companies has gigantic holes in it
When I was a kid I liked to go buy USGS maps of the area around where I lived. While what's online is certainly not perfect, I find the fact that I can get detailed, free maps of almost the entire world nothing short of amazing!
I'm a Google employee, but don't work on maps. I also don't speak for the company... and so on and so forth.
If you zoom in on Google Maps, you can see that the city is marked as Gereida, so it's not the lost city he's claiming it is. Now, I'm happy to listen to people who think it should surface at higher zoom levels, since there's nothing around it, though I suppose that's a feature request for the maps people.
It's marked as a PoI of type "City Center", potentially from a user adding it. It is not in your data set as a city and does not render as such, which is why it disappears at higher zoom levels. This also explains why people down-thread cannot forward resolve the city's name but searching for it works once a small-enough bounding box is established.
So no, Google does not render this city and it's probably inaccessible via your geocoding tools. It's the equivalent of a restaurant from Google Maps's perspective. It goes without saying I feel weird explaining this to you. :)
There is a road going through it, but the city is unmarked. The conclusion in the forum is that this city is Gereida, but a search for it doesn't return anything in GM.
One interesting thing is that the search for "Gereida" does work, but only if I'm already over Sudan. I guess it needs more context to do the search, but "Gereida, Sudan" isn't sufficient.
edit: it does work anywhwere if you search for "Gereida near Buram, Sudan", but I don't think anyone would ever search for that.
It is named on the map view (non-satellite) for the 3 highest zoom levels. I also doubted dmayle's allegation, but did find the label after a minute of searching. I agree with the suggestion that the label should show up on lower zoom levels.
Was this true as of when they had the discussion? Note that the discussion took place in December, and they subsequently added the city to OpenStreetMaps and to Wikipedia. Someone may have added the point of interest to Google Maps since then, or Google Maps may have automatically pulled that information from OSM or Wikipedia.
It is clearly visible in the satellite views on Google Maps, but the map view only shows the main road going through it. I wonder how many other such places could be found just by browsing the web? This seems to be what this guy is doing. If you look at older posts of his, he is working on automatic road following in satellite imagery.
On Google Maps many places have incomplete map data. If you get a bit farther out of Accra, Ghana, quite a few streets will just not be there. That was quite obvious when my sister was there for a few months two years ago but it seems to have gotten somewhat better. Accra is not in the middle of nowhere, it’s a major and important West African city (and 2.3 million people live there).
Maps are imperfect images of reality and keeping them current costs a lot of effort. Depending on who is likely to use them maps will be more detailed in certain places – especially maps that aspire to provide global coverage.
In Accra its missing roads in the suburbs, next to the place I grew up (a small town in Bavaria) its a few (but not all) footpaths in the park missing and a bad match of satellite image and map data (with streets being a few meters off in different directions, a problem that strangely doesn’t seem as prevalent in Accra).
I live in a suburb of Sydney, Australia and in this area most of the residential streets on OSM are unnamed. So my assumption would be that there is a LOT of metadata waiting to be collected in most (all?) cities across the entire world.
More than likely the roads were traced from satellite/aerial imagery and there's no source for road names. If you're in that area you might want to use the Edit button to add the road names (it's really really easy now). If you don't want to sign up for an account, you can use the "Add Note" feature in the lower right and do it anonymously.
I'm not sure unmapped (on google/OSM) cities are rare at all. My daughter was born in a town in Ethiopia and it's not on any map that I've been able to find while it is listed (without lat/lng sadly) in wikipedia.
If there was only one unmapped city it would be considered rare yet there would still be thousands and thousands of people who could share your anecdote. Adding yours to this thread (albeit without any information about it) brings the number to 2 - for all I know there could be hundreds of them, but there could also only be those 2.
For much of the world no-one has ever done large scale mapping. The Soviet Union and USA produced military mapping and gazetteers for targeting, but it often lacks good on-the-ground knowledge. In rural areas it can be difficult to even get a consistent place name from people who navigate from memory.
Yeah, from the way it was written it seemed to me that he was actually there, taking gps measurements. So I was thinking 'why doesn't he just ask somebody there' until I was a few paragraphs in.
the airstrip was built by my friend martijn (https://github.com/MartijnR) when he worked as a construction expert with the Red Cross in Darfur. He had to "hire somebody to chase away goats before plane landing".
The Gazetteer of Sudan: Names Approved by the United States Board on Geographic Names
as well as the file linked under the parent of this post lists this place as Qureida/Quraydah as a well, with Sa‘dūn as the name of the nearest populated place
Look it up in Google Earth with the USHMM layers on. Lots of "destroyed villages" are marked in the surrounding area. Interesting how this city survived while so many others nearby didn't.
Also, the imagery shown is from 2006. Something more recent would be helpful.
Last year "Rostov na donu", a piffling little village with the Mil (helicopter) factory and several million people living in it had only two roads, according to google.
I'm surprised there are towns this large not on maps. It seems like it would be trivial for a large company like Google or Microsoft to write software that scans satellite imagery and cross checks it with current maps to see if anything large is missing. In fact, I would be surprised if they don't already do that. Although I could see this area of the world not being very high priority.
After reading the helpful wikipedia article posted elsewhere in this thread, it seems like the "city" is (or became) a refugee camp. So on old maps (the paper kind digitized by UT--and probably known to Google) it was just a wayside or a small market with a few houses. Geopolitical events led 10's of thousands of people to amass and settle there in a short time. Few places change that fast, but it's not unknown: mining booms and subsequent ghost towns (in a ghost town, the satellite image makes it look larger than its population really is).
This is further reminder that maps are not ever complete, nor intemporal. The human world (roads, buildings) change quite rapidly in both growth and decline.
So you find areas that are missing, then what? Fly somebody there to check out the street names? Remote sensing is a big field, of course they know about naive cross-check techniques like this, the question is what do you do when you find error. And the answer is: you focus on improving the thing that are most relevant to your business first, and war-torn African countries are rather low on that list.
In the satellite image I think it's safe to assume each white block is a tent and each dark outline is a fence. There are many dark outlines with no tents showing where the old population has moved out.
The wikipedia article explains the sudden changes in population of the settlement. It would probably explain the grid layout too.
It looks like the north-west part is the actual town and to the east and south is where it expanded as a camp. Of course, now there is more town than (what I assume was the original) town.
You can see that almost all of it is a nice grid. Makes me wonder why. It's quite amazing despite their poverty, they were able to organize the buildings.
Why would Gereida, a city with a population of 120,000 be considered a lost city just because it is not on an electronic map?The question 'Anyone care to name it?' sounds really patronizing.As if the people currently residing there could not possibly have a name for where they live.
When you spend all of your time inside of that image of the world it's difficult to see the gaps. I love this. It's as if he walked in to a void.