How to use OFDS data

This page provides examples that demonstrate how to use OFDS data in common tools and how-to guides for specific topics.

Examples

Leaflet

The Leaflet example shows how to use Python, Leaflet and Folium to visualise OFDS JSON data.

QGIS

The OFDS QGIS plugin provides support for importing OFDS JSON data into QGIS:

  1. Install QGIS

  2. Install the OFDS QGIS plugin

  3. Download the example OFDS JSON file

  4. Create a new project in QGIS and add OFDS layers

  5. Import the example OFDS JSON file

  6. Explore the attribute table for the nodes and spans layers and use the GeoPackage reference to understand the layer structure and the meaning of the attributes.

How to guides

How to plot coordinates accurately

Coordinates in OFDS data are specified in the urn:ogc:def:crs:OGC::CRS84 coordinate reference system (CRS). To create accurate maps, you need need to set the correct coordinate reference system when using OFDS data.

You also need to pay careful attention to coordinate ordering. urn:ogc:def:crs:OGC::CRS84 is equivalent to EPSG:4326 with reversed axes so, if it is not supported by the tool that you are using, you can set your CRS to EPSG:4326 and ensure that you read coordinates in longitude, latitude order.

For more information on transforming coordinates from one CRS to another, see how to transform coordinates to the correct coordinate reference system.