The Visible/Infrared Imaging Spectrometer of the Future
After the success of JPL’s AVIRIS-NG hyperspectral imaging system, even further improvements were conceived at JPL with input from a range of stakeholders. The Next Generation Imaging Spectrometer (NGIS) resulted from this action.
NGIS is a push broom system that performs high-accuracy imaging spectrometry over the solar-reflected wavelength range 380 to 2500 nm. A single Offner spectrometer design is being used for several airborne instruments: Carnegie Airborne Observatory, National Ecological Observatory Network, and the Next Generation Airborne Visible/Infrared Imaging Spectrometer.
MDL fabricates micromachined slits and the e-beam fabricated gratings for the NGIS spectrometers. The grating for NGIS is a triple-blaze convex grating with the blaze areas arranged as concentric annular zones. The blaze angles and areas are chosen such that the area-weighted spectral efficiency of the first diffraction order equalizes the instrument signal-to-noise ratio when the illumination spectrum and detector spectral responsivity are taken into account.
Through the integration of multiple technologies, including one designed and built by JPL, the Carnegie Airborne Observatory can create 3D chemical maps of tropical forests and other ecosystems around the world.
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Micromachined slit fabricated for the NGIS spectrometer.
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