Develop long-wave infrared (LWIR) immersion grating fabrication techniques and mature high resolution LWIR spectrometer technology to demonstrate an imaging spectrometer testbed for remote sensing of methane.
Our objective is to develop an imaging spectrometer testbed for remote sensing of the trace gas methane. The testbed will demonstrate compact spectrometer optical designs that will be enabled by using immersion gratings fabricated from silicon or germanium. Such designs are significantly more compact than non-immersion designs because the grating refractive index reduces the wavelength inside the material, leading to reduced grating groove spacing and thus reduced grating area to achieve a desired spectral resolution. The gratings will be fabricated by several techniques and evaluated to determine which material and fabrication technique yields the best system performance for this application. The testbed will capture methane emission spectra in the long-wave infrared (7.65 μm wavelength region) and will allow JPL to build on its existing techniques and algorithms for analyzing methane emission spectra in the long-wave infrared.More »
The NASA Hyperspectral Thermal Emission Spectrometer (HyTES) currently images methane plumes in the 7.65 µm wavelength region remotely, but it is challenging for HyTES to determine the absolute uncertainly of the methane retrieval to better than 20% primarily due to its low spectral resolution. We will develop the thermal infrared Methane Sensing Immersion Grating Spectrometer (MSIGS) testbed with an immersion grating tuned to the 7.65 µm methane feature. Simulations predict that this will allow methane retrievals of with nearly 10X improvement on the current uncertainty, with effectively zero interference error and substantial sensitivity right at Earth’s surface. MSIGS will also be imaging like HyTES allowing mapping of any methane plumes at lower concentrations.
Remote detection of methane from space could provide revenue for commercial satellite providers.
Methane sensing is of interest to a variety of agencies involved with energy production, gas monitoring, and intelligence.More »
|Organizations Performing Work||Role||Type||Location|
|Jet Propulsion Laboratory (JPL)||Lead Organization||NASA Center||Pasadena, CA|