EOL Facility: 
In-Situ Sensing Facility (ISF)
Maintenance Status: 
Used by these EOL facilities: 
Visualization and quality control of upsonde and dropsonde radiosonde soundings. Command line, batch and GUI based interfaces are available. For support questions, email eol-aspen(at)ucar.edu.


Operating System: 

ASPEN Versions

The changes that are visible to users are given below. The many changes that are made for software maintenance and obscure bug fixes are not listed here.

For Aspen version 3.4.0 and up, download the appropriate installer for your operating system below.

Please contact us if you need older Aspen versions or information about previous version history.

3.4.4 — May 1, 2020

CentOS 7 OSX 10.14 (Mojave) Windows 10
  • Fix missing libraries in CentOS installer
  • Fix bug in setting OB number from commandline Aspen
  • Add config parameter to disable calculation of vertical winds
  • Set config items for autosave and fixed data directory to take effect immediately, rather than after restarting Aspen
  • Add check that produces a warning popup when Aspen identifies a floating sonde
  • Visually identify post-splash data in raw tab
  • Add ability to set post-splash data from raw tab

3.4.3 — Jan 6, 2020

CentOS 7 OSX 10.14 (Mojave) Windows 10
  •  Correct order of flag bits in BUFR output
  • Set time in BUFR section 1 to launch time rather than processing time
  • Add hundredths of seconds to time column in FRD output
  • Read in EOL and FRD files in pass-through mode so processing cannot be applied twice
  • Correct text for NW option of eyewall azimuth menu in the Comm tab
  • Add 'no to all' option when prompted to save configuration changes upon closing Aspen
  • Add autosave options for levels CSV and summary text'
  • Automatically include newest Aspen user manual in installation packages
  • Fix pixelation in graphical interface on Retina displays
  • Fix infinite loop on startup when specified dbpath is incorrect
  • Fix a bug where saving a file from the QC tab would also save any config set changes
  • Fix bug in setting ObsNum from command line Aspen
  • Add maximum altitude interpolation gap as a configurable parameter
  • Only include dry bias correction metadata for RD94 sondes
  • Add ability to add or override sonde context metadata (agency, platform type and ID, project, flight) while processing and saving to output
  • Add ability to add dataset DOI to netCDF and CSV output
  • Add vertical winds to netCDF output
  • Only include config set items that directly influence processing in netCDF and CSV output metadata
  • Add sonde serial number to netCDF and CSV output metadata
  • Add equilibration times for temperature, RH, and pressure to netCDF and CSV output metadata

3.4.2 — Jul 24, 2019

CentOS 7
  • Add a missing dependency to the Linux version

3.4.1 — Jul 3, 2019

CentOS 7 OSX 10.14 (Mojave) Windows 10
  • Fixed bug where ignoring lat/lon wouldn't remove them from QC data

3.4.0 — May 20, 2019

CentOS 7 OSX 10.14 (Mojave) Windows 10
  • Threshold RH values of up to 110% to 100% before removing invalid RH
  • Add wind error check, which removes wind speed and direction if error value for GPS winds is too high
  • Build Aspen on Windows 10 and OSX Mojave
  • Update Qt graphics library to version 5
  • Switch Aspen release numbering and AEV coding to semantic versioning
  • Set monotonic pressure check off by default in dropsonde config sets
  • Set buddy check wind speed threshold to 10m/s^2 in dropsonde config sets
  • Add ability to automatically correct early launch detects
  • Update attribute icons


Derived from the HRD Editsonde program (1998). Initially developed for AFRES 53rd Hurricane Hunters real-time operations. Later expanded for general upsonde and dropsonde application.