Webservice ppsd FR EN

This service queries a database of power spectral densities (PSDs) calculated over one-hour segments. Individual PSDs are aggregated to show the probability distribution of seismic noise levels. PSDs are calculated with the method described by McNamara in 2004 using ObsPy for a particular network/station/location/channel combination.

Usage

Command Description
/histogram PDF generation
/spectrogram Spectrogram generation
/value Extraction of values as text
/availability Extraction of the periods for which PSDs are available

Citation

TODO

How it works

Operation

  1. When a request is made to the PPSD WebService, it is parsed and passed to the SeedPSD exploitation engine.
  2. SeedPSD extracts the metadata for the target (NSLC) from the inventory.
  3. SeedPSD extracts from the database the statistical values corresponding to this target over the requested period (start/end)..
  4. SeedPSD initializes a PPSD object from these values.
  5. SeedPSD uses this PPSD object to generate an image configured according to the options specified in the request parameters.
  6. SeedPSD sends the generated image to the client (browser, CLI, ...) that made the request.

Feeding

Data

  1. When integrating a MiniSEED file in the Resif-DC data center (Node B), the file is transmitted to the SeedPSD ingestion engine.
  2. SeedPSD checks the availability and consistency of the metadata corresponding to the file.
  3. SeedPSD initializes a PPSD object from the content of the MiniSEED file.
  4. SeedPSD extracts and stores in database the main statistical values calculated by PPSD.

Metadata

  1. When integrating a StationXML file in the Resif-DC data center (Node B), each epoch (NSLC start/end) it contains is transmitted to the SeedPSD ingestion engine.
  2. SeedPSD extracts the metadata related to this era from the inventory.
  3. SeedPSD extracts and stores in database the main values allowing to identify metadata changes (instrumental response, sampling rate, ...)
  4. When metadata are already present in the database, SeedPSD compares them with the new ones before inserting them and, in case of discrepancy, invalidates any statistics calculated from them.