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Format specifications for arbitrary file formats

Mandatory Metadata

The metadata must follow the Binding Regulations for Storing Data as netCDF Files from Helmholtz-Zentrum Hereon. A complete list can be found in the SOP for netcdf.

Metadata file

  • The mandatory metadata must be provided as a separate JSON file with the ending '.json'.
  • One metadata file can describe a dataset on one or any number of data files.
  • The data files do not need to have the same file format.
  • Data files must be referenced in the metadata file with a variable data with their relative file path starting from the metadata. The filepath can be a prefix for multiple files. If this is the case, the prefix must not end special characters (e.g. '*') to indicate a prefix.

It is recommended to store the metadata either in the same directory as the data files (version 1) or have the data in a subdirectory beside the metadata file (version 2).

version 1:
- metadata.json
- data-file-1
- data-file-2

version 2:
- metadata.json
- data-directory
    - data-file-1
    - data-file-2

This is a minimal example of a valid metadata file:

{
    "data": ["data-directory/data-", "data-"],
    "title": "title",
    "originator": "name",
    "creation_date": "date",
    "Conventions": "CF-1.8",
    "institution": "Helmholtz Centre for Environmental Research GmbH, Germany",
    "contact": "email@ufz.de",
    "source": ["raw_data_name", "variables", "used_methods"],
    "crs": "epsg:0",
    "additional": ["additional", "data"]
}

The file can contain any amount of additional fields. These will be ignored in the MinIO-GeoNetwork-Workflow.