<title>Optical calibration results for the series of special sensor ultraviolet limb imagers (SSULI)</title>

Abstract

The Special Sensor Ultraviolet Limb Imager (SSULI) program involves the development of a series of five ultraviolet limb imaging spectrographs by the Naval Research Laboratory for the Defense Meteorological Satellite Program. In addition, a duplicate sixth instrument, the Low Resolution Airglow/Aurora Spectrograph (LORAAS) will be flown aboard the Space Test Program ARGOS satellite in late 1997. These instruments will measure vertical intensity profiles of the Earth's airglow in the extreme and far ultraviolet (800 to 1700 angstroms) with 19 angstroms resolution. The instruments view the limb using a rotating mirror to scan the 0.1 degree(s) X 2.4 degree(s) field of view from 750 km to 50 km tangent altitude. SSULI measurements will be used to infer altitude profiles of ion, electron and neutral density. The first SSULI is scheduled to launch in 2000, and coverage from all the instruments will provide a continuous atmospheric data set spanning an entire solar cycle. The first four SSULI instruments are complete, and detailed optical calibrations have been performed. Assembly and calibration of the remaining SSULI instrument and LORAAS are underway, and preliminary results are available. Preliminary results of the first SSULI instrument were reported in 1994. This paper updates the calibration results of the first instrument and presents a summary of the results of the next three SSULI instruments. Comparison between instrument characteristics are also discussed, including variations in calibration techniques. A brief discussion on the periodic calibration verification of the SSULI instruments during storage and prior to launch is included.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.