Inspired by the success of Wikipedia, OpenStreetMap is a project to create a free editable map of the world. OSM is considered a prominent example of volunteered geographic information. OpenStreetMap is built by a community of mappers that contribute and maintain data about roads, trails, cafés, railway stations, and much more, all over the world. OpenStreetMap’s community is diverse, passionate, and growing every day. Our contributors include enthusiast mappers, GIS professionals, engineers running the OSM servers, humanitarians mapping disaster-affected areas, and many more.
OSM is open data: you are free to use it for any purpose as long as you credit OpenStreetMap and its contributors. Rather than the map itself, the data generated by the OpenStreetMap project are considered its primary output.
In 2012, the launch of pricing for Google Maps led several prominent websites to switch from their service to OpenStreetMap and other competitors. Chief amongst these were Foursquare, Craigslist who adopted OpenStreetMap, and Apple, which ended a contract with Google and launched a self-built mapping platform which uses TomTom and OpenStreetMap data.
Map data is collected from scratch by volunteers performing systematic ground surveys using tools such as a handheld GPS unit, a notebook, digital camera, or a voice recorder. The data is then entered into the OpenStreetMap database. The availability of aerial photography and other data from commercial and government sources has added important sources of data for manual editing and automated imports
OpenStreetMap uses a data structure with four core elements:
Nodes are points with a geographic position, stored as coordinates (pairs of a latitude and a longitude) They are used to represent map features without a size, such as points of interest or mountain peaks.
Ways are ordered lists of nodes. They are used both for representing linear features such as streets and rivers, and areas, like forests, parks, parking areas and lakes.
Relations are ordered lists of nodes and ways. They are used for representing the relationship of existing nodes and ways. Examples include turn restrictions on roads, routes that span several existing ways (for instance, a long-distance motorway), and areas with holes.
Tags are key-value pairs. They are used to store metadata about the map objects (such as their type, their name and their physical properties). Tags are always attached to an object: to a node, a way or a relation.
The main copy of the OSM data is stored in OSM’s main database. The main database is a PostgreSQL database, which has one table for each data primitive, with individual objects stored as rows.
## OpenStreetView, a street level imagery platform OSV is a web site, openstreetview.org, free and open source mobile apps for Android and iOS, a specialized Map Editor, a plugin for JOSM, and a back end server.
The apps are optimized for driving but also work well for biking and walking scenarios. Apart from recording trips, you can also upload your trips to OSV. This will happen automatically when you enter WiFi, if you want. Finally you can review your local and server trips and see your profile. Even if you have not logged in on the web site, you can log in to OSV with the apps, also through OSM OAuth. Either way, this will create an account for you on OSV.
One thing that is really specific to OSV is that you can link the app to an OBD2 dongle in your car. Those are little devices that read from the OBD2 port in your car. Almost every car has one. OSV will read the speed and curve to improve the accuracy of the GPS signal that is recorded for your trip.
The OSV apps also have sign detection built in. So this is not done on the server but on the client! This means that it will detect speed limit signs, and more to come, in real time and can warn you if you are speeding. This warning feature is almost ready and will be in one of the next builds.
it is almost completely open source. You remain in full control of the data you upload to OSV. You can always delete individual photos, trips or even delete everything and remove your account if at any moment you don’t want to be a part of OSV any longer.