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Level-0 flows

The Level-0 flows generate the Level-0 products from the raw data sessions of the CADIP stations, with the DPR Level-0 processors.

Flow Parameters Description
process-l0 session, env_args, force_systematic, verbose Generic entry point for all the missions, started by the systematic processing after the staging of a session: checks the session, stages it if needed, then runs the Level-0 flow of the mission (process-s1-l0 or process-s3-l0) as a sub-flow.
process-s1-l0 session, env_args, force_systematic, verbose Sentinel-1 Level-0 processing of a session already staged, see Sentinel-1 flows.
process-s3-l0 session, env_args, force_systematic, verbose Sentinel-3 Level-0 processing of a session already staged, see Sentinel-3 flows.

The parameters of a run are the session, e.g. S3A_20260807020505053186, and the owner of the products (env_args). The other parameters are read from the default settings of the Level-0 processing of the mission, in the s1l0-default-setting or s3l0-default-setting Prefect variable (see Customise the DPR processing). With force_systematic, the workflow of the processing is systematic: the events of the generated products start the next processing of the chain. In systematic processing, process-l0 is started with force_systematic by an automation after the staging of each session, see Systematic processing.

Steps of process-l0

  1. Check the session identifier and deduce the mission from it.
  2. Read the default settings of the Level-0 processing of the mission.
  3. Check that the Dask cluster given by dask_cluster_name and the dask-staging cluster are running.
  4. Look for the session in the catalog collections input_collections. If it is not there, find it in the CADIP collections cadip_collections and stage it. An unpublished (expired) session is rejected.
  5. Run the Level-0 flow of the mission (process-s1-l0 or process-s3-l0) as a sub-flow, that reads the settings again and runs the generic processing flow process-generic with:
    • the session as input product,
    • the session date as start_datetime and end_datetime (the sensing dates are not available for a session),
    • the satellite deduced from the session identifier,
    • the processor, pipeline, Dask cluster and collections of the default settings.

The generated products are published in the catalog collections given by generated_product_to_collection_identifier.