3. Processes

The following data and metadata processings are performed by each entity:

  1. Scientist: Experiment metadata

  2. Facility: data and subnetwork metadata

  3. A-Node: cross-verification data and metadata

3.1. Scientist: Experiment Metadata Processing

The responsible cientist for an experiment provides metadata of this experiment and all of its included campaigns(see section Scientist-Provided Metadata for the file format). If the experiment has multiple campaigns, the scientist adds new campaigns as the experiment progresses and transmits this file to the A-node.

The experiment file is sent via email to smm_anode@services.cnrs.fr.

3.2. Facility Processing

OBS facilities collect data during a data collection Campaign. A facility also must have information (including instrument responses) about its OBSs . These data and metadata are initially processed on the facility side to obtain basic data (A-node miniSEED) and metadata (SMM StationXML). The Facility then sends this data to the SMM A-Node using a specific file-transfer protocol.

Facility-level processing consists of :

  • Collecting raw data, in a proprietary or standard format.

  • Evaluating the raw data for errors, and fixing them if possible, while saving information about any processing/transformation performed.

  • Converting the data to A-node miniSEED format (uncorrected for clock drift, if possible)

  • Preparing metadata in SMM stationXML format. The obsinfo tool may be used for this.

  • Sending data and metadata to the A-Node

3.2.1. Facility Tools

This section presents an example how a facility (INSU-IPGP) prepares metadata and data including some of tools used for this preparation.

  • Metadata tools

    • Obsinfo: Create SMM StationXML files using a text-based instrumentation database and relatively clear and compact “subnetwork” files that describe essential information for each station.

  • Data tools

    • lcfix: fix some data errors in lcheapo files.

    • lc2ms: transform data from lcheapo format to miniseed format

    • mscat: concatenate miniseed files

    • sdp-process: create/append to a provenance file for each command-line operation (the above commands do this automatically)

  • Transfer tool

    • rsync to send data in miniseed format

3.3. A-Node Processing

Once the A-Node receives Experiment metadata from the Scientist Provider and data and metadata from the Facility Provider(s), it :

  • pre-validates (validates) the data and metadata

  • performs clock correction (drift and possibly leapsecond) on data

  • creates visual validation graphics for the Facility and Scientific Auditors, and awaits the validation

  • sends the data and metadata to the Epos-France Data Center

3.3.1. A-Node Tools

The A-Node automatically processes data and metadata, except for visual validation, for which human intervention is required. The sections Data and Metadata Visual Validation and ValidationGuide explain this visual validation.