diff --git a/federation/index.md b/federation/index.md index 69c7f2d0e..2538ab275 100644 --- a/federation/index.md +++ b/federation/index.md @@ -88,6 +88,62 @@ only either ARD processes **or** "standard" processes can be used in one process is not yet supported. One option to nevertheless achieve a combination of process types is to run ARD on Level-1 data, save the results of the job, and then in a second job load results and perform additional computations. +### Enforce back-end selection for common collections + +Some collections are provided by multiple underlying back-ends, +possibly with differences in spatial or temporal coverage. +This is exposed in the collection metadata with `federation:backends` summary, e.g.: + +```json +{ + "id": "WATER_BODIES", + "type": "Collection", + ... + "summaries": { + "federation:backends": ["vito", "sentinelhub"], + ... + } +} +``` + +When a user submits a processing request, +the federated platform will try, by default, to automatically determine +which underlying back-end is best choice for the actual processing, +based for example on the requested spatial extent. + +You can however also enforce the selection of a certain back-end +by using the metadata property filtering feature +of the `load_collection` process. +For example, with the Python client, to enforce the selection of +the "sentinelhub" back-end: + + + + + + ## Processes Each of the underlying back-ends of the federation can define its own set of available processes,