Field verification is an important part of keeping OpenStreetMap data accurate. Field mapping exercises are largely manual, cumbersome, or require internet connectivity. OpenStreetMap has an active mobile editing ecosystem, but doesn’t offer the same editing experience as iD for beginners. Mapping campaigns often need a tool as good as iD that allows edits from the field to verify existing data and improve data quality.

Observe is a cross-platform, offline-first field mapping tool for OpenStreetMap, perhaps the first of its kind. Our primary goal was to build an application that makes field observation easy, and provides a comparable experience to iD on Android and iOS — with some success. Observe focuses on browsing OSM data and allows users to add new points or verify existing information. The edits made offline are stored on the phone and uploaded when the mapper goes online. Observe is a product of several iterations of user research and a couple years of conceptualization.

Focus on POIs, offline editing, and conflict resolution

The current version of Observe focuses on adding Points of Interest (POIs), and editing attributes of polygon geometries. Observe comes with most of the OpenStreetMap presets, and it's customizeable. It's easy to create a POI, add attributes to it, and save. Observe allows a user to come back to a POI, and edit further, before uploading when the user is offline.

Observe is offline-first. The application allows users to download an area of interest, and then disconnect from the Internet to map. This is extremely useful for large-scale field verification, managing mapping campaigns, and focused neighborhood level data gathering. All changes made while offline are stored on the phone, and uploaded automatically in the background when the user is back online. Our focus was to keep survey data along with the actual geometries -- no more geospatial matching and analysis.

One of the fundamental ways to improve the offline mapping experience is to employ an easy-to-use conflict resolution strategy. Observe currently notifies the user of an edit conflict. The user can compare the changes between their version of the feature and upstream, and decide to ignore or overwrite the edit.

An ecosystem for managing custom spatial data

Observe is the latest addition to our suite of tools around the OpenStreetMap ecosystem for managing custom spatial data at scale. Combining Observe with tools like osm-seed allows any organization to manage their spatial data from collection, storage, analysis, and publishing securely on the cloud, or on dedicated infrastructure.