The TIRIS is a demonstration system of a thermal infrared imaging spectrometer operating with uncooled optics.
Target applications include investigating the detection of plume of various compounds from air or space borne hyperspectral sensors for environmental monitoring and for CW applications.
TIRIS It is a pushbroom wedge spectrometer based on an extrinsic silicon (Si:As) 64×20 FPA, with 100 µm square pixels, hybridized to a Si ROIC. The FPA is a HYWAYS device produced by Hughes (an Aerojet PATHS FPA was used initially). As all extrinsic devices, the FPA operates at 10K.
General description: | Linear Variable Filter (LVF, or wedge filter): a custom multi-layer interference filter stack designed to match the pixel size of the FPA
| Cooling: a closed cycle 2-stage Gifford MacMahon He refrigerator with 1 watt capacity at 10K
| LVF mount: mechanically mounted ~300 µm over the FPA with external screws for fine position adjustment (translation and rotation)
| 64 Spectral bands ~0.1 µm resolution (along track direction)
| 20 spatial pixels (cross track direction)
| Spectral range 7.5 to 14 µm
| Optics: Cassagrain all-reflective uncooled telescope
| Internal, cooled (10K) filter wheel with 8 positions for spectral calibration narrow band pass filters
| Out of band blockage achieved with a cooled BaF filter
| ZnS uncooled window
| Prototype electronics:
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| TIRIS functions in the laboratory
| It is used for the study of gas plume detection
| Plumes of various compounds are simulated by containing the target compound in a KBr windowed cell within the FOV of the TIRIS
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