SSUSI-lite: next generation far-ultraviolet sensor for characterizing geospace

Abstract

SSUSI-Lite is an update of an existing sensor, SSUSI. The current generation of Defense Meteorological Satellite Program (DMSP) satellites (Block 5D3) includes a hyperspectral, cross-tracking imaging spectrograph known as the Special Sensor Ultraviolet Spectrographic Imager (SSUSI). SSUSI has been part of the DMSP program since 1990. SSUSI is designed to provide space weather information such as: auroral imagery, ionospheric electron density profiles, and neutral density composition changes. The sensors that are flying today (see http://ssusi.jhuapl.edu) were designed in 1990 - 1992. There have been some significant improvements in flight hardware since then. The SSUSI-Lite instrument is more capable than SSUSI yet consumes ½ the power and is ½ the mass. The total package count (and as a consequence, integration cost and difficulty) was reduced from 7 to 2. The scan mechanism was redesigned and tested and is a factor of 10 better. SSUSI-Lite can be flown as a hosted payload or a rideshare – it only needs about 10 watts and weighs under 10 kg. We will show results from tests of an interesting intensified position sensitive anode pulse counting detector system. We use this approach because the SSUSI sensor operates in the far ultraviolet – from about 110 to 180 nm or 0.11 to 0.18 microns.