NuSDaS User's Guide

Structure of Files and Directories

NRD and Directory Structure

All data files are located in directories called NuSDaS root directory (hereafter called as NRD). NRD has following structure:

• NRD/
  • nusdas_def/
    • dataset.def ... definition file
  • subdirectories
    • subdirectories (structure defined by the definition file)
      • ...
        • data_file

The NuSDaS interface searches for NRD as directories named NUSDASnn, where nn is a numbers from 01 to 99. In operational suites of JMA, NRD is firstly named in lowercase letters ending with .nus (such as gf_fcst_p.nus) by conventions, and symbolic links to it (say NUSDAS30) is created.

A NRD may have many definition files. A definition file corresponds to a particular data type. It describes subdirectory structure and can refer many data files. Therefore there is a inclusion relation:

record ∈ data file ∈ definition file = data type ∈ NRD

Records are grouped in files by following rules:

• Records of different Data Type is stored in separated files.
• Records of different Base Time is stored in separated files.
• It is dependent to the definition file whether records of different Member is stored in separated files or not.
• It is dependent to the definition file whether records of different Valid Time is stored in separated files or not.
• Records of same data type, base time, member and valid time will be stored into same data file regardless of their Plane or Element.