High-Resolution CH4 Enhancement Observations near Industrial Sites using the GHGSat-D Demonstration Satellite
Abstract
In June 2016, GHGSat, Inc. launched its demonstration satellite GHGSat-D - the first and only satellite on orbit designed for single-site measurements of GHG emissions with high spatial resolution (< 50 m). We present previously unpublished single-pass measurements showing evidence for point-source emission plumes from industrial sites such as the San Juan (USA) coal mine and Lom Pangar (CR) hydroelectric reservoir. Furthermore, we show that emission estimates derived from satellite observation are corroborated by third-party estimates
In order to present results in proper context, we review the imaging Fabry-Perot measurement concept at the hear of GHGSat-D. We use a novel retrievals technique where the emitter site of interest is captured in a sequence of overlapping two-dimensional images. The combined effect of the Fabry-Perot resonator and the scrolling scene gives a different spectral sampling of each surface location in every image. While our data processing toolchain does not produce a conventional hyperspectral dataset, it does yield a spectral decomposition of the spatially resolved signal that can be compared to a model that includes atmospheric radiative transfer and the instrument's pixel-dependent spectral responsivity. We describe the optimal estimation procedure used to retrieve methane from each of the approximately 250,000 ground locations observed. In the presence of instrument errors, the methane retrieval can contain spurious enhancements that limit our ability to detect plumes. We quantify the performance limits of GHGSat-D and discuss hardware improvements that are being implemented in next generation satellites.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A54G..07J
- Keywords:
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- 0345 Pollution: urban and regional;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3394 Instruments and techniques;
- ATMOSPHERIC PROCESSESDE: 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0478 Pollution: urban;
- regional and global;
- BIOGEOSCIENCES