OSM Flight - Stratford Theatre
When we are not talking about bus stops and transport mapping, at Ito World we are usually editing OpenStreetMap or planning how to take the glorious OSM to even greater heights.
While talking at the Society of Cartographer’s summer conference, we heard from UKMap; a new dataset for certain areas of the UK created entirely from scratch, and designed to rival the OS’ MasterMap in detail. Its market, and the reason for its creation, is those who are fed up with the Ordnance Survey’s onerous licensing regime. Critically, those who pay to use UKMap data are not bound by Derived Data, the practice where the OS claims copyright over any data you create.
Although we currently licence some proprietary mapping data, our future is an open data future. We are constantly working with the OSM community to improve the coverage and richness of OpenStreetMap data.
What was of interest though, was the process for creating the UKMap dataset. It provided some real insight into what we do well in OpenStreetMap and what we can do better. UKMap is created in two stages: tracing aerial imagery and then paper and pencil surveying on the ground.
In this day and age I was expecting to hear of fleets of trucks with GPS units, or hundreds of surveyors armed with tablet PCs and customised mapping software. But no! Tracing over aerial photography and then a follow up ground survey, with people on the ground annotating paper maps which are then scanned in and digitised.
Sound familiar? Well, that’s how we’ve been building OSM of late, tracing aerial imagery and ground surveys, usually with a GPS.
We have long had aerial imagery to trace over, thanks to our chums at Yahoo!, but the arrival of Mike‘s fantastic Walking Papers has given us the most powerful addition to the OSM stack. Choose the area you will be mapping, print your Walking Paper, draw on the map adding details, scan and upload the image, and thanks to Mike’s technical wizardry the annotated Walking Paper is then available for you to trace and digitise online.
Annotated Walking Paper for Tottenham
Before, we relied on GPS tracks to give us roads and paths, but it is a steep learning curve for those not already familiar with geogeek technology. Now, its as simple as scribbling on some paper while walking and tracing over the top. Listening to the UKMap talk it was very interesting to learn that the Walking Papers approach, was found to be much more efficient and just as accurate as surveying with a tablet PC. Importantly, the fact that UKMap have created a commercial mapping product with the same approach as OSM, validates our methods.
What are we lacking? High resolution aerial imagery. The aerial photography we have is getting old now and is not very detailed. We need higher resolution, and more recent aerial photography to improve OpenStreetMap. To kick things off, at Ito World we have sponsored OpenStreetMap’s first aerial photography flight. We sent up the intrepid John Robert Peterson, armed with a camera to photograph Stratford-Upon-Avon from the skies. We are organising an OSM mapping party at the AGI Geocommunity conference today to follow up with some ground surveying.
You can see the results here. Using MapWarper, created by the effervescent Chippy, you can reference the images to groundpoints and rectify the imagery. This is by no means perfect, but it is a first step into new territory for OSM. We need better aerial imagery and the cost is steadily decreasing, and there are many local authorities who already have the data. Indeed, Surrey Heath and Devon are working to make their aerial photography available to OpenStreetMap.
OSM Tiled Aerial Photography for Stratford
We hope this is the start of many Local Authorities and organisations to make data available to OSM, we will do the hard work such as image cutting, tiling and hosting for you. Make it available and help make a better open mapping dataset of your area. If you are at GeoCommunity and interested in donating some aerial imagery or any other data to OSM come and speak to me (I am chairing the Geoweb stream). Or drop me a line and I will point you in the right direction.