In early October, Maxar Technologies’ Radiant Solutions team members attended State of the Map US 2018 OpenStreetMap Conference, in Detroit, Michigan. The OpenStreetMap (OSM) community is filled with mappers, validators, developers, and both public and private organizations all focused on building a better map. The OSM-US community has continued to grow not only through contributors to the map, but also through collaboration with the private sector and tech community.

Major themes from the conference included machine learning, local and global impacts of OSM, and tool development. Validation of OSM data was an underlying theme throughout the conference, even if it was not explicitly on the agenda. Radiant Solutions shared methodologies that we have been implementing to ensure data quality in two talks: Validation of the Users, By the Users, For the Users and MapRules.

One of the biggest challenges for OSM is educating participants on how to contribute valid data. My talk, Validation of the Users, By the Users, For the Users, encouraged the use of existing open source tools, like MapRules, MapRoulette, the HOTOSM Tasking Manager, and the OpenStreetMap Oversight Engine (Osmose), to create workflows for OSM data validation.

OSM Ecosystem Validation Tools

Within the OpenStreetMap community there are a great deal of tools, developed by companies, non-profit organizations, and volunteers, all with the goal of identifying potential data issues as well as tools to fix these issues. However, many of these tools are siloed in terms of the users who are aware of their existence, preventing integration opportunities.

There are many common OSM validation tools, such as:

…and there are many, many, more:

Validation Workflows

While error detection tools are numerous and documentation for individual tools exists, there is not a well documented body of knowledge that explains how all of these tools are orchestrated into logical workflows. Shared workflows and tutorials give new users insight for growth and opportunities for improved skill sets when working within OSM. Through combining of any number of these tools, users can streamline their workflow to validate and correct errors in OSM data.

For example, users can:

Collaborate on mapping or validating an area using the Tasking Manager developed by HOTOSM

Identify which features are to be mapped using MapRules

Identify topological and tagging errors using Osmose

Validate and rectify large numbers of errors using MapRoulette

A Notional QA/QC Workflow

The example below highlights a notional mapping campaign highlighting our approach.

Using Tasking Manager, we can identify the area we want to map, and then create a number of projects to better manage and track our progress. With our MapRules integration, we ensure the the mapping is done to a predetermined and consistent specification.

Figure 1: The Tasking Manager is a platform allowing for collaborative mapping over an area of interest.

At this stage, communication with mappers is key. With MapRules doing an initial validation check, we’re giving immediate feedback to a potentially new mapper each time they save an edit. Through the Tasking Manager, we are also able to ask questions of the project/campaign manager, and communicate directly with mappers with information related to the project.

After the projects within the campaign are completed, the OSM data is checked with Osmose. Osmose’s comprehensive quality checks (both geometry and attribute) provide opportunity for robust validation of data, beyond what was initially captured as part of a mapping campaign.

For this campaign, we select the “Way Approximate” analyser, which identifies highways and waterways which lack spatial detail. Many of these features were originally mapped from mid-to-low-resolution imagery like Landsat, however, the availability of high-resolution imagery in OSM from DigitalGlobe, a Maxar Technologies Company, we can now address many of these issues on a global scale.

Figure 2: The OpenStreetMap Oversight Engine, runs a series of analysers which identify potential geometry and attribute errors in OSM data.

Depending on the scale at which our validation needs to occur, there are a few different approaches to take when validating. First, we would simply address issues one by one in iD or JOSM editors, via Osmose. If our validation errors are densely contained to a city-scale, we again use the Tasking Manager to create a project and systematically fix the errors. However, in this case, we want to cover an entire region, so to efficiently move through the corrections, we’ll use MapRoulette to send the mapper to each subsequent error.

Figure 3: MapRoulette creates challenges of micro-tasks, aimed at efficient completion over a large number of instances.

To review, we can see below the entire workflow from start to finish. It takes a combination of tools and feedback mechanisms at all steps of the process to ensure data issues are being fixed.

This workflow uses MapRules to control which features a contributor can add to the map through a project in the HOTOSM Tasking Manager. Once the data is in OSM, it can be checked for tagging and topological errors using Osmose, after which, errors can be fixed through the HOTOSM Tasking Manager, iD or JOSM editors, or micro-tasked using MapRoulette.

An OSM Call to Action

As I mentioned, the OSM-US community has been open and welcoming to mappers of all skill sets and interests. The workflow highlighted here and in my State of the Map US talk appears obvious for more experienced mappers within the OSM community, however, for a new mapper wanting to “level-up” their mapping contributions, diving into the wiki, forums, and listservs can be overwhelming. The intent here is to provide a framework that enables new mappers to make more substantive contributions sooner.

As part of the OSM community, I urge others to share their validation workflows, provide constructive feedback to new mappers, and make quality assurance and validation a priority through all steps of your mapping process.

By combining multiple tools, new OSM contributors at all experiences levels can be equipped to more easily address issues. In doing so, mappers can expand their knowledge of the OSM schema, feel more empowered to correct other issues, and feel more connected to the greater OSM community.

What’s Next?

At Radiant Solutions, we are revealing insights where and when it matters, enabled by open source software innovation. In this post I’ve mentioned MapRules several times. MapRules is an open source tool developed by Radiant Solutions which will empower campaign managers to direct the focus and requirements of a given mapping campaign through the creation of custom feature presets and validation rules to be used by contributors editing in iD and JOSM. We’ll be featuring MapRules in our next post!

Catch up on all the talks from State of the Map US 2018 on Youtube, including MapRules and Validation of the Users, By the Users, For the Users.

We are always on the lookout for talented developers, engineers, and analysts. If you are interested in a new career opportunity, we are currently looking for Software Development Engineers, Senior Software Engineers, Systems Engineers, and DevOps Engineers.