Title: QWEST and HyTES: Two New Hyperspectral Thermal Infrared Imaging Spectrometers for Earth Science
Primary Author: Bjorn Eng
Organization: Jet Propulsion Laboratory
Co-Author(s): Simon Hook, Sarath D. Gunapala, Cory J. Hill, William R. Johnson, Andrew U. Lamborn, Pantazis Mouroulis, Jason M. Mumolo, Christopher G. Paine, Vincent J. Realmuto, Daniel W. Wilson
We have recently developed a laboratory prototype of an airborne thermal infrared imaging spectrometer termed the Quantum Well Earth Science Testbed (QWEST). Based on our experience with QWEST we are developing the airborne Hyperspectral Thermal Emission Spectrometer (HyTES). HyTES is scheduled for completion in 2011. Both instruments utilize several key components: slits, spectrometers, gratings and detectors developed at the Jet Propulsion laboratory. In particular, each design uses a Dyson spectrometer, an electron microbeam grating and a Quantum Well Infrared Photodetector (QWIP) focal plane array. The Dyson configuration uses a single monolithic prism-like grating design which allows for a high throughput instrument (F/1.6) with minimal ghosting, stray-light and large swath width. The configuration has the potential to be the optimal imaging spectroscopy solution for lighter-than-air (LTA) vehicles, unmanned aerial vehicles (UAV), manned airborne platforms and spaceborne platforms due to its small form factor and relatively low power requirements. The instrument specifications will be discussed as well as design trade-offs. Calibration results from QWEST (noise equivalent temperature difference, spectral linearity and spectral bandwidth) will be presented as well as some field results. Field testing of QWEST was performed to acquire data from a variety of standard minerals and these will be compared to laboratory measurements of the same minerals made with an FTIR spectrometer.