Title: Optical design of the Snow and Water Imaging Spectrometer (SWIS) for small satellites and CubeSats
Presenting Author: Pantazis Mouroulis
Organization: Jet Propulsion Laboratory
Co-Author(s): Byron Van Gorp, Robert O. Green, Daniel W. Wilson, Daniel Preston, Holly Bender Jet Propulsion Laboratory; Chris Smith, ATK Inc.

Abstract:
The Snow and Water Imaging Spectrometer has been designed to address localized coastal and snow cover applications. It can satisfy the stringent requirements of those applications by maximizing the light collection and signal to noise ratio as well as minimizing the polarization sensitivity, operating in the spectral range 350-1700 nm. A compact Dyson form and appropriate beam folding allow the spectrometer, reflective telescope (100mm, F/1.8, 10 deg linear field of view), and on-board calibrator, to fit in a 4U volume. A mechanical proof of concept design is shown. The optical system performance is discussed, as are the stray light considerations that drive the design and lead to the requirement for a special detector antireflection-coating. A form of the spectrometer with twice the field size (1200 spatial elements) that can provide higher spatial resolution from satellites larger than CubeSat form is also discussed.