Category Archives: Cartography

POSM, OSM without the Internet

Disclaimer: I am in no way affiliated with the POSM or its development.  I’m just an OSM contributor who thought this was neat and wanted to share the love.

For a while I’ve been envisioning some sort of system that would allow map data to be collected over a large area and then committed and later shared without an Internet connection.  Going into a rural area without sufficient or existing Internet connectivity would surely be a problem with using tools for compiling and rendering OpenStreetMap (OSM) data.  I had come up with a few solutions that were not unique and seems to have been tried before.


Yep, just toss your GPS tracks, pictures, and JOSM output onto a USB thumb drive and walk/drive it over to a centralized location, where Internet connectivity is available, for processing.  Sure, it might take a while to collect all the information and take a while longer to redistribute all the information to the people in the field but it works.


Okay, being a network geek this is my favorite solution; build your own network!  For the record, I’m not talking about stringing wire from village to village like soldiers did around Europe in WWII.  No, I’m talking about building wireless MANs to connect wired/wireless LANs that may already exist in these villages (or we can build our own!).

Adding our own infrastructure (email, web, and other servers) to the network would provide basic communications between villages with a potential connection to the Internet from a faraway town.

But this is far from fun for a software geek (I’m not one of those).  From here enter the POSM.


The Portable OpenStreetMap, or POSM, device is a small server that hosts all the tools needed to compile, edit, and publish collected mapping data without Internet connectivity.  The project was discussed at the US State of the Map (2016) and the video is a must-watch.


Of course a POSM could be added to either a Sneakernet or Intranet to allow for distributed data to be collected faster but the POSM, alone, seems to make working with this data much easier in the field.

Back to my thoughts

Honestly, my first thoughts around making a box like this, even before I heard about POSM, was the syncing of data back to the master OSM database.  If you watched the video to the end it appears someone else in the crowd had the same concern.  The answer to this was the use of git to manage conflicts.  To me this is very smart as git was made for this type of use-case (distributed data that needs to be compiled together at a core location).

I do wonder how well POSM would work if you had one in each village with MAN connections between and having the POSMs sync among themselves, sharing the data in near-real time.  This would be beneficial as there would be a backup of the data in the event one of the POSM devices died and could add some redundancy.  Providing connectivity could also aid in communications between sites through IRC or XMPP.

Lots of ideas…  Lots of options…

My Mapbox article for

Mapbox Office

Mapbox Office

Back in December I met with Eric Gundersen (@ericg), CEO of Mapbox, and Alex Barth (@lxbarth), lead of Mapbox’s Data Team, at their DC office to discuss their work within the open source community.  I was happy to find their office have the “start up” feel to them and everyone seems to be very passionate about their work.  I’ve since run into a few Mapbox employees that, even outside the office, seem to have maps in their hearts.  I suspect this company will provide even more FOSS goodness in the future and will be one to watch.

If you haven’t read the story it can be found on the website.

Looking for something to map?

Recently people have released tools to make it easy to find something to map on the OpenStreetMap (OSM) project.  If you’re looking for something to do take a look at one of these tools:


The Humanitarian OpenStreetMap Team (HOT) focuses on areas in the world that aren’t mapped well (or at all) and where there is a need for a humanitarian effort.  If you’ve been around OSM for a while you’ll probably remember reading something about the mapping effort in Haiti after the earthquake back in 2010.  The humanitarian effort didn’t stop there.  Most recently Typhoon Haiyan has left many international emergency responders in need of mapping data to be able to move their resources around and perform damage assessments.  Their projects are listed on their website and allow you to checkout a task for mapping or validating other mapping work.  As work is completed it goes into the hands of the responders on the ground.


Okay, this is a neat idea.  Whenever edits or massive data entries are done there are times when everything doesn’t mesh well.  Maybe a road crosses another road which looks fine when viewed on a screen but breaks navigation and leads to inefficient routes.  These bugs can go unnoticed unless someone tries to use the data and finds a problem or someone might happen to stumble upon the issue.  That’s where Maproulette comes in.  This system gets programmed with a specific problem that needs to be fixed.  Right now that problem is the connectivity issue I mentioned.  It combs through the OSM database looking for just these issues and records where they are located.  A visitor to the site is shown the next error in the list with an offer to bring up an editor so they can either fix the problem or verify a false positive.  Because the edits are quick to fix I’ve been able to knock out forty or more in an hour without much thought.  (Hey, some people knit and watch TV, I fix mapping bugs and watch TV!)

Battle Grid

Battle Grid data of Greenville, NC

Battle Grid, Greenville NC

Oh yes, the Battle Grid!  Sounds similar to a cage match doesn’t it?  When the 2012 TIGER mapping data from the US Government was released it was discovered that the quality of the data was much better than the TIGER maps that many of the United States’ roadways were originally based upon in OSM.  Battle Grid (from Maproulette) combs through the OSM database and compares the TIGER 2012 data to what’s in OSM and then shows discrepancies as colored blocks.  The redder the boxes the more discrepancies there are in that grid.  So a quick look at the map shows you where your mapping skills are most needed.  Some additional tools have been created that allow you to overlay the TIGER 2012 data under the OSM data for comparison.  This allows you to visually see the problem areas and fix them quickly.

There are other ways to find data that might be missing.  Just walking around your community and visually comparing the OSM data to what you see with your own eyes certainly helps.  Validating data against satellite imagery is also good.  As I wrote about in an early post, collecting points of interest and address information is also quite useful while out and about.  Getting involved in OSM is easy and learning how to map isn’t difficult either.  So get out there and get mapping!

Tools for Contributing to the OpenStreetMap Project

Okay, I admit it, I’m a closet cartographer. There are few things that excite me like looking at, building, and working with maps. Luckily for me the OpenStreetMap (OSM) Project was born and I started contributing back in 2008. Back when I was starting contributing I was making minor changes to the TIGER map data, cleaning up the bad data that peppered my local town. Today I’m still cleaning up data but I’m also adding points of interest (POIs), such as restaurants, shops, and hotels, and also address information that makes the overall data more useful to consumers.

The tools used to edit and collect mapping data have improved over the past few months with many applications coming to the Android operating system. The physical size of many Android devices allows field collection of data without having to lug around a laptop. With many of the features now available on the portable platform, collecting mapping data is easier than ever.

Tools of the Trade


Still the workhorse tool of my contributions, I use the Java OpenStreetMap Editor (JOSM) for most of my edits on the project. Whether I’m using GPX files of trails and roads collected from the field or adding POIs and other map features from satellite imagery, JOSM makes it easy to make advanced additions and changes. Many mapping programs use JOSM as a springboard for their data to get into the OpenStreetMap repositories. If you are serious about working with OSM data then you should get comfortable with using JOSM.


OsmAnd Maps and Navigation, an Android, is usually marketed as a program for viewing OSM data and using it for navigating from one point to another. This program allows you to download, directly to your device, the mapping data which is quite helpful if you don’t have an Internet connection to get this data like other mapping solutions.

From a contributor’s point of view, OsmAnd allows you to create GPX track files that can be later edited with JOSM and also allows you to create, and upload directly to OSM, POIs such at restaurants that you may be visiting at the time. This is a great feature for me as I will sometimes find myself somewhere that isn’t officially on the map.

Keypad-Mapper 3

Keypad-Mapper 3 is an Android application that allows easy mapping of house numbers. Using JOSM or Potlatch 2, the online OSM editor, Keypad-Mapper data can be imported, verified, and then uploaded into the OSM repositories.

Other applications

Other software is available to collect, modify, and use OSM mapping data. If maps interest you or if you are just looking for a good, open source mapping solution take a look at OSM and enjoy the large amount of global work that goes into the project every day.

Shameless Plug: Contribute to digital cartography with OpenStreetMap

I’ve been trying to write an article for for the last year dealing with open source cartography.  I finally got around to finishing the article and it was published yesterday.  I’m not exactly happy with the way it turned out so I’m hoping to do a part two discussing more than just the OpenStreetMap project and perhaps comparing various open source projects to those that are just crowd-sourced.

I appreciate feedback!