Design of a small robust DASH interferometer suitable for CubeSat observations of Thermospheric winds
Abstract
The Doppler Asymmetric Spatial Heterodyne (DASH) concept has been proposed to measure upper atmospheric winds. The approach is identical to the concept of Spatial Heterodyne Spectroscopy (SHS) except one interferometer arm exhibits an additional optical path offset which optimizes the instrument for the measurement of atmospheric winds. A DASH interferometer is a field-widened Michelson that utilizes diffraction gratings instead of mirrors to measure an interferogram over a large path difference interval without moving parts. This feature enables the instrument to simultaneously monitor multiple atmospheric lines and calibration lines to track instrumental drifts. The DASH interferometer described in this paper is designed for satellite measurements of thermospheric winds using the upper atmospheric red line at λ=630.0 nm in a limb imaging geometry. The interferometer departs from previous designs in that the fringes are localized on a plane following the interferometer which eliminates the need for exit optics to re-image the interferogram onto the detector. Only one focusing optic is required to form an image of the limb through the interferometer onto the fringe localization plane. The resulting instrument assembly is smaller and lighter than previous designs making it suitable for deployment on a multi-U CubeSat platform. This paper will discuss the design of the real-fringe interferometer, its advantages and limitations when compared to earlier DASH designs and its possible implementation on a CubeSat.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMSA23A2146H
- Keywords:
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- 0310 ATMOSPHERIC COMPOSITION AND STRUCTURE / Airglow and aurora;
- 0358 ATMOSPHERIC COMPOSITION AND STRUCTURE / Thermosphere: energy deposition;
- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques