3-2. Key concepts¶

Services

Services, in the context of the Geospatial Explorer, are platforms that serve up data or catalogues of data.

Data services¶

In tutorial 2 we added data from one service: the World Cover layer from a Web Map Service (WMS). We also added a number of background maps, which came from tile mapping (XYZ) services.
Services often declare their capabilities — that is, they can be queried to find out what data layers are available. This is part of the WMS and WMTS standards, and the Config Builder can fetch the capabilities to find out what layers are available in a data service.

Another type of service is a catalogue service. Rather than serving map images directly, it describes what data exists and where to find it. For example, this might provide some information about where a COG file is and what it contains.
The standard for Earth Observation data is the SpatioTemporal Asset Catalog (STAC).
ESA's Project Results Repository (PRR) is a store of data produced by ESA-funded EO projects, and it is available as a STAC catalogue.

The final type of service is a data bucket: cloud-hosted storage provided through an S3-compatible store, such as AWS S3 or an APEx-provided object store.
Data buckets are typically used for file-based storage, including raster files such as COGs and vector files such as GeoJSON or FlatGeoBuf.
When a bucket is publicly accessible, the Config Builder can browse its folders and files, acting as a file picker so that you can select data to add to a layer.

You can add services to a Geospatial Explorer config, and then search or browse those services to discover data that might be useful to add in.