Special Sensor Ultraviolet Limb Imager

The United States Naval Research Laboratory (NRL) built five of these ultraviolet spectrographs for the United States Air Force (USAF) Defense Meteorological Satellite Program (DMSP) block of 5D3 satellites. ==Launch==

The first sensor was launched on the DMSP F16 spacecraft in October 2003 into a Sun-synchronous 830 km circular orbit at a local time of 0800-2000 UT. and preservation of the last DMSP satellite. ==Mission details==

Measurements are made from the extreme ultraviolet (EUV) to the far ultraviolet (FUV) over the wavelength range of 80 nanometers to 170 nanometers, with 1.8 nanometer resolution. The satellites will be launched in a near-polar, Sun-synchronous orbit at an altitude of approximately 830 km. The Low Resolution Airglow and Auroral Spectrograph (LORAAS), a SSULI prototype, was launched on board the Advanced Research and Global Observation Satellite (ARGOS_(satellite)) on February 23, 1999. LORAAS data was used to validate SSULI algorithms that convert raw measurements (Figure 2) into useful environmental parameters that characterize the upper atmosphere. ==Software==

An extensive operational data processing system has been developed to generate environmental data from SSULI spectral data. Spectral data from the LORAAS instrument is also part of this platform. This system, known as the Ground Data Analysis Software (GDAS), includes operational data reduction software using advanced science algorithms also developed at NRL, a customized graphical user interface (GUI), and comprehensive validation techniques. Programs are designed to generate a SSULI Prep file from multiple data sources including Raw Sensor Data Records (RSDR) at the Air Force Weather Agency (AFWA), HIRAAS real-time data assembled at US Space Command, and an extensive HIRAAS infobase on site at the Naval Research Laboratory. ==Technical information==

The sensor has a field-of-view of 2.4°x0.15° and sweeps out a 2.4°x17° field-of-regard during each 90 second scan, with wavelength coverage between 800Å and 1700Å at 23Å resolution. The field of view scans ahead of the spacecraft in the orbital plane through a 17° field of regard, corresponding to approximately 75–750 km altitude. ==References==