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PH5: What is it?



PH5 is the recommended archival format for active source data sets.  PASSCAL has transitioned from SEG-Y to PH5, PASSCAL's implementation of the hierarchical data format, version 5 (HDF5) data model, as the preferred archival format for active source data sets.  The strengths of HDF5 made it an attractive model for an active source archival data format.


  • is extensibile and portable1, allowing it to evolve and operate on a variety of platforms through a number of programming interfaces,
  • is self describing1 and allows direct access to parts of the file without the need to parse the entire file,
  • has been in use for two decades and is utilized in a variety of disciplines, from aerospace to the medical field.


The PH5 format takes advantage of these attributes, storing separately the data and the meta-data, as is done within SEED (need a link to the seed intro page).  Visit The HDF Group to learn more about HDF5.


1   Folk, M., E. Pournal 2010. Balancing Performance and Preservation Lessons learned with HDF5,

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