High spatial resolution imaging of methane and other trace gases with the airborne Hyperspectral Thermal Emission Spectrometer (HyTES)

摘要

Currently large uncertainties exist associated with theattribution and quantification of fugitive emissions of criteria pollutantsand greenhouse gases such as methane across large regions and key economicsectors. In this study, data from the airborne Hyperspectral ThermalEmission Spectrometer (HyTES) have been used to develop robust and reliabletechniques for the detection and wide-area mapping of emission plumes ofmethane and other atmospheric trace gas species over challenging and diverseenvironmental conditions with high spatial resolution that permits directattribution to sources. HyTES is a pushbroom imaging spectrometer with highspectral resolution (256 bands from 7.5 to 12 µm), wide swath (1–2 km),and high spatial resolution (∼ 2 m at 1 km altitude) thatincorporates new thermal infrared (TIR) remote sensing technologies. In thisstudy we introduce a hybrid clutter matched filter (CMF) and plume dilationalgorithm applied to HyTES observations to efficiently detect andcharacterize the spatial structures of individual plumes of CH,HS, NH, NO, and SO emitters. The sensitivity andfield of regard of HyTES allows rapid and frequent airborne surveys of largeareas including facilities not readily accessible from the surface. TheHyTES CMF algorithm produces plume intensity images of methane and othergases from strong emission sources. The combination of high spatialresolution and multi-species imaging capability provides source attributionin complex environments. The CMF-based detection of strong emission sourcesover large areas is a fast and powerful tool needed to focus on morecomputationally intensive retrieval algorithms to quantify emissions witherror estimates, and is useful for expediting mitigation efforts andaddressing critical science questions.