• Measurements provide scientific data supporting military and civil systems
  • Assists in predicting atmospheric drag effects on satellites and re-entry vehicles
  • Ionospheric data products ingested by DoD state-of-the-art assimilative space weather model, GAIM
  • New models of global electron density variation
  • First operational instrument of its kind
  • Provides new technique for remote sensing of Ionosphere and Thermosphere from space


  • Passively measures vertical profiles of natural airglow radiation from gases and ions in upper atmosphere and ionosphere from LEO
  • Exploits Extreme-UltraViolet (EUV) to Far-UltraViolet (FUV) emissions
    • Wavelength Range of 80 nm to 170 nm, at 1.5 nm Resolution
  • Uses a spectrograph with a mirror which scans from 27 to 10 degrees below the satellite horizon every 90 seconds
    • Scans a vertical slice of the atmosphere from 50 - 750 km altitude
  • Produces electron density profiles, neutral density profiles, atmospheric composition, and temperatures of upper atmosphere
  • Leverages the NRL previous high resolution airglow/aurora Spectroscopy (HIRAAS) Experiment, flown onboard the DoD Space Test Program (STP) Advanced Research and Global Observations Satellite (ARGOS)
  • Next-generation follow-on sensor SSULI+ provides improved capabilities in more compact design.


  • Third of five SSULI remote sensing instruments was launched on October 18, 2009 onboard the DMSP F-18 satellite
  • In August 2012, SSULI on F-18 transitioned from Cal/Val to Operations at the Air Force Weather Agency.
  • Independent analysis of SSULI data in GAIM has determined strong operational impacts:
    a) 1st most significant impact on peak heights
    b) 2nd most significant impact on total electron content
    c) 2nd most significant impact on peak electron density