Data Overview

This is a general overview of the data files and formats recorded by the ISS for a typical deployment.

Typically each ISS delivers data from several instruments and in multiple formats.  Final data are provided in NetCDF format whenever possible.  Unidata develops the NetCDF data format and also software libraries for accessing the data through a standard API.  Many tools already exist for accessing netcdf data.  More information is available through Unidata:

Each ISS project may comprise multiple ISS sites.  Within the dataset for each site, the data streams are divided into subdirectories with the names given in the table below.  Not all subdirectories will exist for all sites.

surface_met The surface measurements in netcdf format, as generated in real time in the field.  Depending upon the deployment, these data files may be generated directly from an ingest program with a serial connection to a Campbell data logger, or they may be converted from the raw NIDAS data files in the nidas directory.  The durations of the files may vary from 30 minutes to several hours, but they will contain all of the recorded surface data without any overlaps.
RS41 Sounding Data 1-second resolution sounding profiles collected using the Vaisala MW41 Sounding System 
GAUSdata Raw data files from the GAUS sounding software, in use between 2002-2016 
logs Text log files from various components of the ISS system.  These are not useful to users of the data, but they are kept in the dataset for completeness and for diagnosis by ISS data managers.
prof915l Realtime consensus winds from the profiler, in netcdf, for the profiler's "low mode".
prof915h Realtime consensus winds from the profiler, in netcdf, for the profiler's "high mode".
prof915mom Moments data received from the radar software (POP) in realtime over a serial connection and ingest to netcdf.  These are the files from which the soap plots are generated.
rass915 Realtime consensus virtual temperatures, in netcdf.
ceilometer Data files recorded directly by the Vaisala ceilometer software, with the .DAT extension.  These are text files, thus it is possible to examine and interpret the data in the files, but EOL does not provide any other format for the data.
soap_plots The prof915mom data are plotted in various ways with IDL.  These are the plot images.
spc Raw spectral data files recorded by the POP profiler program.
spc_nc The POP raw spectral files in SPC format converted to netcdf with the popexam program.
nidas The raw surface data records generated directly from the NIDAS data acquisition software.  These data files are in a special NIDAS format, typically with the extension .dat, best accessed through NIDAS tools.  Most users only need the netCDF data files in the surface_met dataset.
nima NIMA is the NCAR Improved Moments Algorithm from the Research Applications Program (RAP).  It is fuzzy-logic and pattern recognition software for deriving moments, winds, and virtual temperatures from the raw SPC data files.  The output is separated into days of the year.
nima/ncdata The NIMA ASCII output is converted to netcdf files by an IDL script.  Moments data have the extension .momnc, winds are .windsnc, and rass are .rassnc.
nima/plots Plots generated from the NIMA netcdf data using IDL.

There may be subdirectories for other information collected in real-time, but
those are rarely outside EOL.