Data Files & Formats 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 the Unidata NetCDF home page.

Each ISS project may comprise multiple ISS sites. 

Surface Meteorology Surface measurements from various sensors are consolidated into daily 1-minute netCDF files. 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. Surface data includes measurements from Lufft meteorological sensors, visibility and precipitation sensors, radiometers, and barometers. Other surface sensors may be incorporated in the netCDF files depending on the project.  
RS41 Radiosonde

1-second resolution sounding profiles collected using the Vaisala MW41 Sounding System.

NCAR/EOL/ISF Radiosonde NetCDF Data

EOL Sounding Data File Format (older ascii format)


NetCDF files are provided for all ceilometer measurements (CL31, CL51, and CL61). DAT text files are heritage ascii files are generated by Vaisala software in 6hr increments for the CL31 and CL51 ceilometers only. Daily netCDF files are provided for the CL31 and CL51. 5-minute netCDF files are generated for the CL61 by proprietary Vaisala software. In addition to the standard ceilometer data reporting, the CL61 offers depolarization measurement that enables differentiation between solid, liquid, or mixed-phase clouds and precipitation.

Windcube Lidar Lidar data processing is proprietary to Leosphere/Vaisala Windcube software. The raw data are converted into the CfRadial (CF-1.7) compliant netCDF4 files by the LROSE RadxConvert processing package. netCDF files are generated for each scan strategy. In addition to the CfRadial data, a Velocity-Azimuth Display (VAD) wind profile product is calculated using select Plan-Position Indicator (PPI) scans. These daily netCDF files follow the convention produced by the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facilities (Newsom et al. 2015)
449 MHz Wind profiler Auto and cross correlation function files are generated at 30 second averaging time using the ICRA intermittent clutter filtering algorithm to reduce the effect of transient targets such as birds. The wind correlation files are then analyzed to generate 5-min and 30-min daily winds and 30 second moment netCDF files.
915 MHz Wind Profiler 30-minute consensus winds and moments are generated by NIMA (NCAR Improved Moments Algorithm from the Research Applications Program (RAP)) in netCDF format. NIMA is fuzzy-logic and pattern recognition software for deriving moments, winds, and virtual temperatures from the raw spectral data files recorded by the profiler program.
RASS The profilers can operate in a RASS mode to measure profiles of virtual temperature using an acoustic source to generate propagating sound waves that perturb the radio refractive index of the air sufficiently to be detectable by the profiler. RASS data are provided in separate netCDF files and contain 5-minute consensus averaged virtual temperature.