QGIS

Accessing OS NGD data with OS NGD API – Features via QGIS

QGIS is an open GIS (Geospatial Information System) desktop application that allows you to display, interrogate, visualise and create geospatial information including from geo-centric APIs (for example, a WFS).

The instructions that follow demonstrate how to connect to OS NGD API – Features using QGIS.

What you need

• QGIS (version 3.12.0 or later).

• A preloaded basemap, for example, OS Maps API or OS Vector Tile API.

• OS NGD API – Features added to an API project in the OS Data Hub with an API Key. See Getting started with an API project for more information.

Instructions

Connecting to OS NGD API – Features

If you are connecting to the OS NGD API for the first time then you can follow either step 2 or step 3 to set up a new connection via QGIS. It is not necessary to follow both steps.

1

Set up a new connection

Once a new project with a base map has been set up, zoom in to a small area to reduce the number of requests that are initially sent to the API. Select Layer > Add Layer > Add WFS / OGC API - Features Layer.

2

Create a new connection in the WFS Connection dialog

In the Data Source Manager | WFS / OGC API - Features dialog click New and in the New WFS Connection dialog:

• Name: Provide a name for the connection. You can reuse this connection in the future.

• URL: Copy the OS NGD API – Features endpoint address from the OS Data Hub and paste it into this field. Your API Key is automatically appended to this URL in the key parameter.

• Authentication: Leave these settings at their defaults. You do not need a username or password as authentication is done through your API Key.

• Version: Click Detect to identify the version.

• Enable feature paging: Select this option, if necessary.

• Page size: Enter a maximum page size. This limits the page size to a maximum number of features. We recommend a setting of about 100 to speed up response times. Larger values may result in a very slow response time.

• Other: Leave the other settings at their defaults.

• Click OK.

QGIS Create a New WFS Connection dialog.

3

Create a new connection using a saved server configuration

The Ordnance Survey GitHub repository contains API resources contains configuration files that can be loaded directly into the QGIS Data Source Manager following the Connecting to web services guide in the QGIS documentation.

osngd-resources/api-resources at main · OrdnanceSurvey/osngd-resourcesGitHub

Access the OS NGD API resources here

4

Adding layers to the map

Data Source Manager | WFS / OGC API - Features dialog:

• Select your new connection in the dropdown, if necessary.

• Click Connect.

QGIS Data Source Manager | WFS > Server Connections.

When you click Connect, a list of layers available in OS NGD API – Features populates in the main box:

• To add a layer to the map: Select the layer to highlight it. You can select multiple layers by using the Ctrl key.

As best practice, only load layers that relate to your current task – not all layers. The more features you call, the longer it takes to load them into QGIS. In addition, each feature, regardless of its layer, counts towards your rate limits.

• Only request features overlapping the view extent: Select this option.

• Click Add.

QGIS Data Source Manager | WFS / OGC API - Features.

The layer will then display in the Layers panel and the data will display on the map:

QGIS UI showing OS NGD API – Features data in the Layers panel and map area.