I spent the past weekend in Washington DC for State of the Map (SotM) US, the OpenStreetMap conference. It ended up selling out, with around 500 attendees, making it the largest OpenStreetMap event yet. As with previous SotM events I’ve attended (the last one being in Denver in 2011), I found it very enjoyable and interesting, and there was great energy about it as always, much more than at traditional GIS events. Many thanks to the organizing team for a great event!
Below I summarize a number of items that I thought were of interest. I should also say that I missed a number of interesting presentations - there were two tracks and much of the time I wished I could have been in both talks! Fortunately though all the talks were recorded so I will check out those I missed online, and recommend you do too! Actually most of the talks are already online - just click through on the online schedule. Well done to the SotM organizing team for getting this done so quickly and professionally!
I also got some nice pictures of cherry blossom, and saw my English football (soccer) team, Liverpool, win a hugely important and exciting game against Manchester City together with several other SotM attendees, at the Queen Vic pub, home of the DC Liverpool Supporters Club - thanks to Jeff Johnson of Boundless for being the ringleader on this outing!
The most interesting and potentially significant announcement was that MapBox released the spec for their vector tiles format, which they have been talking about for a while, and have been using internally to generate dynamically styled raster tiles at mapbox.com. Dane Springmeyer talked about more technical aspects of it, and Nicki Dlugash from Mapbox and Mamata Akella of the National Park Service talked about using Tilemill 2, which can both consume and export vector tiles, from a user perspective.
One nice aspect of rendering vector tiles directly in the browser is that you can do very interactive zooms and nice transitions, as shown in this short demo from Nicki's presentation. Another advantage is that you can do very dynamic restyling, on the server or client. And thirdly there are attractions for offline use in terms of data volumes compared to raster tiles.
Vector tiles are not a panacea though, raster tiles continue to have their advantages too. A key one is being able to exactly match complex symbology from an existing GIS, which is important in a lot of the applications we work on at Ubisense - large utilities can have a hundred feature types, thousands of symbology rules and complex custom annotation, which is not easy to replicate. Also raster tiles give great interoperability between different systems, an advantage that many people underestimate. And they work well in older browsers, whereas most vector technologies require newer browsers and a lot of large enterprises are still stuck on older versions of Internet Explorer :(. This is less of an issue for mobile apps on tablets or smart phones though.
As an aside, I find it a bit ironic that when I started doing GIS in the 1980s, most products then stored their graphics in map tiles, which caused various problems with editing in particular, and managing features that were split between multiple tiles. The big focus of everyone in the industry at that time was to move away from tiles to a "continuous database" where you didn't have to split things across tile boundaries. But now tiles are cool again !! It's interesting how many computing problems oscillate in a similar way, moves between thin and fat clients being another example - mainframes to PCs to web browsers to smart phones, etc.
But caveats notwithstanding, these vector tiles definitely have a lot of potential and I certainly plan to be playing around with them in the near future.
The elephant in the room with OpenStreetMap, unfortunately, continues to be licensing. I hesitate to even get into this topic, but will try to briefly summarize. There has been a long and painful process over the past several years to migrate the license for OpenStreetMap from Creative Commons to a new license called ODbL. Many smart people, many of whom are friends of mine, have put a huge amount of effort into creating this new license and managing the difficult process of steering the community through the change, all with great intentions. A key part of both the old and new licenses is the notion of "share alike" - roughly speaking that you can take a copy of the OpenStreetMap data, but if you make improvements to the data then you need to also make those freely available under the same license.
However, there was a very strong message from a range of organizations presenting at the conference that they were prevented from doing much of what they would like to do with OpenStreetMap because of the license - from government organizations like USGS, New York City and the National Park Service (NPS) to private companies like MapBox and Foursquare. Alex Barth did a presentation just on the licensing topic. I am not a lawyer, and I have also been steering pretty well clear of the license discussions in the last year or two, but I think there are two broad areas of concern. One is that if you use OpenStreetMap data in conjunction with your own private data, if there is sufficient interaction between the datasets then there is a risk that he license could oblige you to make your private data freely available also, which is obviously not acceptable in many situations. Some things are clearly fine, like just using OpenStreetMap tiles as a backdrop to your data. But when you get into editing the underlying data in some way then it's more complicated. A second category is that certain government organizations like USGS and NPS are mandated that the data they create and maintain has to be public domain. So they are unable to incorporate OpenStreetMap data as they would like to, because then at least some aspects if not all of their data cannot be released as public domain, it has to have the ODbL license which imposes additional conditions on the use of the data.
There seem to be two schools of thought on how to proceed, as articulated by Mikel Maron:
- An interesting presentation from Mike Skalnik on what github is doing with geoJSON - sort of cool for smaller simpler datasets, but with limitations for more complex applications
- Jeff Johnson of Boundless talked about GeoGit, which is an ambitious initiative to manage distributed updates, and something I've been interested in exploring but haven't had a chance to get to (one thing we did a lot of work on at Smallworld back in the early 1990s was version management, which has a lot of parallels with this). Jeff talked about some interesting scenarios in how this could potentially be used to manage two way sync between OSM and a local government (or other) GIS (license constraints permitting!)
- Mapillary is an interesting looking project that aims to create a crowdsourced Street View from stitched together photos taken by smart phones, something that I've been thinking for a while is a project that is needed. You can download their app for your smart phone and upload some pictures - I had a very quick play capturing some data near my home this afternoon and it came out fairly well, I will experiment more in due course.
- John Firebaugh gave an excellent talk on "Implementing change in OpenStreetMap", with lots of great insights on managing community based projects. He had a lot of good one line pearls of wisdom, one that I liked in particular was that "perfect" is the enemy of "much better than we have today".
- Lyzi Diamond gave a great talk on "Maptime" meetups, which I found especially interesting as one of the organizers of the Geospatial Amateurs meetup in Denver. They take a very hands on approach to helping people learn new things, and have developed quite a few lessons and tutorials that are available on github, and I certainly plan to look more at those.
- OSM Tchoutchou is an entertainingly named site that maps French trains in near real time using OSM, which is quite cool to watch.