Sources of geospatial data in vector format

Vector-based geospatial data represents physical features as collections of points, lines, and polygons. Often, these features will have metadata associated with them. In this section, we will look at some of the major sources of free vector-format geospatial data.

OpenStreetMap

OpenStreetMap (http://openstreetmap.org) is a website where people can collaborate to create and edit geospatial data. It describes itself as a "free editable map of the whole world made by people like you."

The following screenshot shows a portion of a street map for Onchan, Isle of Man, based on data from OpenStreetMap:

Data format

OpenStreetMap does not use a standard format such as shapefiles to store its data. Instead, it has developed its own XML-based format for representing geospatial data in the form of nodes (single points), ways (sequences of points that define a line), areas (closed ways that represent polygons), and relations (collections of other elements). Any...