Downloading Data

Each SEC-IMS record can offer one or more distribution links — URLs from which the dataset can be downloaded or accessed. The distribution links appear in the metadata view for the record (see Chapter 2).

Distribution types

A single record may offer several distribution links, depending on the kind of data and how it has been published. The most common are:

  • File download — a direct link to the dataset as a file (GeoPackage, Shapefile, GeoTIFF, CSV, document). Best when you need the data on your own machine for offline use.
  • OGC API endpoint — a URL into the SEC-IMS API for the corresponding data type:
    • Features for vector data (e.g. https://secims.example/pygeoapi/collections/<id>/items).
    • Coverages for raster data (e.g. https://secims.example/pygeoapi/collections/<id>/coverage).
    • Tiles or PMTiles for tiled raster or vector data.
    • Maps for rendered map images (PNG, JPEG).
  • Service capabilities — a URL pointing at the OpenAPI document or service description for programmatic use.
NoteScreenshot needed

record-distributions — The Distributions section of a populated metadata record, showing several link types side by side: a file download, an OGC API Features endpoint, and an OGC API Tiles endpoint. Annotate each link type.

Choosing a format

The right distribution to use depends on what you intend to do with the data:

  • For desktop GIS analysis — download the file (GeoPackage or GeoTIFF where available), or, for live access that always reflects the latest data, connect to the OGC API endpoints directly from QGIS (see Chapter 7).
  • For web visualisation — use the Tiles or PMTiles endpoints. They are bandwidth-efficient and stream only the area you are viewing.
  • For scripts and notebooks — use the Features or Coverages endpoints, which return standards-based JSON or raster responses (see Chapter 7).

Coordinate reference system

Vector and raster distributions on SEC-IMS are published in EPSG:4326 (WGS 84 longitude/latitude) by default. The OGC APIs can return data in other CRSs on request — see the API documentation for the crs and bbox-crs parameters.

Some file downloads are also available in the regionally relevant British West Indies (BWI) grid where the data custodian has chosen to publish it that way. The CRS of each file is recorded on the metadata page.

File size and large datasets

Datasets larger than the default 50 MB upload cap may be split across several distribution links, or published only through tile and API endpoints (which stream data as needed and do not require a single large download). Where a dataset has a large companion file, the metadata page indicates the file size before you click the link.

NoteScreenshot needed

record-large-download — A record whose distribution links include a clearly labelled file size, demonstrating where the size appears on the page. Use a dataset of at least a few tens of MB so the size is visible.