Compact Lyman-Alpha Spatial heterodyne Spectrometer (CLASS)
| Compact Lyman-Alpha Spatial heterodyne Spectrometer (CLASS) | |
|---|---|
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| Principal Investigator | Sona Hossein |
| Institution | Jet Propulsion Laboratory (JPL) |
| Technology Readiness Level | 3 |
| Instrument Type | Far-UV Spectrometer |
| Project Status | Active |
| Project ID | 20-HTIDS20-0028 |
Overview
The Compact Lyman-alpha Spatial heterodyne Spectrometer (CLASS) is a spectrometer that makes of an interferometric technology called Spatial Heterodyne Spectrometer (SHS) that enables CLASS to obtain ultra-high sensitivity data from angularly extended and diffused targets such as the solar corona. The low-mass, compact configuration of CLASS enables sensitive, high-resolution spectroscopy for SmallSat missions. CLASS is configurable for a variety of spectral lines with a very narrow bandpass anywhere from the FUV to the visible, but for development, CLASS is configured to target the H I Lyα line at 1216 angstrom.
Principle of Operations
SHS is a form of a Fourier Transform Spectrometer. SHS consists of a grating (which functions as a beam splitter/beam combiner), a flat mirror, and a roof mirror (to laterally separate the input beam from the output beam). In an all-reflective cyclical SHS configuration, the incoming collimated light is incident on the grating at a normal angle; splits into two arms, with each arm incident on the flat mirror and roof-mirror; the dispersed light then recombines through the same path back on the grating for the second diffraction before exiting the interferometer toward the sensor. The input field stop is an integral part of the SHS, eliminating the fringe pattern degeneracy outside the interferometer FOV. In SHS, the interference fringes have high visibility over only a precise surface in the observation space called the Fringe Localization Plane (FLP).
Advantages and Disadvantages
Flight Heritage
Applications
Image Gallery
Funding
Presentations, Publications, and Patents
Presentations
- Hosseini, Sona ; Vourlidas, Angelos ; Vievering, Juliana T., High-sensitivity ultra-compact Lyman-alpha Spectrometer, 2022 COSPAR Conference
Publication
- Sona Hosseini, Measurements of Atomic Line shape at Ultra-High Spectral Resolution at Short Wavelengths, Heliophysics 2025 workshop Measurement techniques and technologies, 2021