HyTI: Thermal Hyperspectral Imaging from A Cubesat Platform

The HyTI (Hyperspectral Thermal Imager) mission, funded by NASA's Earth Science Technology Office InVEST (In-Space Validation of Earth Science Technologies) program, will demonstrate how high spectral and spatial long-wave infrared image data can be acquired from a 6U CubeSat platform. The mission will use a spatially modulated interferometric imaging technique to produce spectro-radiometrically calibrated image cubes, with 25 channels between 8-10.7 μm, at a ground sample distance of ~70 m. The HyTI performance model indicates narrow band NEΔTs of <; 0.3 K. The small form factor of HyTI is made possible via the use of a no-moving-parts Fabry-Perot interferometer, and JPL's cryogenically-cooled BIRD FPA technology. Launch is scheduled for no earlier than October 2020. The value of HyTI to Earth scientists will be demonstrated via on-board processing of the raw instrument data to generate L1 and L2 products, with a focus on rapid delivery of precision agriculture metrics.

1. INTRODUCTION

Since the launch of the Landsat 4 Thematic Mapper, scientists interested in studying the long-wave infrared (LWIR) thermal properties of Earth’s surface, atmosphere, and water bodies at high-to-moderate resolution have been limited to making measurements at a 60-120 m ground sample (e.g. Landsat TM, ETM+), in no more than five spectral bands (e.g., Terra ASTER). This barely scratches the surface of the potential that the LWIR region of the spectrum has for quantifying Earth system processes. Operational acquisition of high spatial and spectral resolution LWIR data from Earth orbit would yield an hitherto unattainable measurement record for Earth scientists. Applications include mapping the chemistry of rocks and minerals exposed at Earth’s surface [1], the composition of volcanic gas and ash plumes [2], and quantifying soil moisture content and evapotranspiration [3].