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  1. Book ; Online: Level0 to Level1B processor for MethaneAIR

    Conway, Eamon K. / Souri, Amir H. / Benmergui, Joshua / Sun, Kang / Liu, Xiong / Staebell, Carly / Chan Miller, Christopher / Franklin, Jonathan / Samra, Jenna / Wilzewski, Jonas / Roche, Sebastien / Luo, Bingkun / Chulakadabba, Apisada / Sargent, Maryann / Hohl, Jacob / Daube, Bruce / Gordon, Iouli / Chance, Kelly / Wofsy, Steven

    eISSN: 1867-8548

    2024  

    Abstract: This work presents the development of the MethaneAIR Level0–Level1B processor, which converts raw L0 data to calibrated and georeferenced L1B data. MethaneAIR is the airborne simulator for MethaneSAT, a new satellite under development by MethaneSAT LLC, ... ...

    Abstract This work presents the development of the MethaneAIR Level0–Level1B processor, which converts raw L0 data to calibrated and georeferenced L1B data. MethaneAIR is the airborne simulator for MethaneSAT, a new satellite under development by MethaneSAT LLC, a subsidiary of the Environmental Defense Fund (EDF). MethaneSAT's goals are to precisely map over 80 % of the production sources of methane from oil and gas fields across the globe to an accuracy of 2–4 ppb on a 2 km 2 scale. Efficient algorithms have been developed to perform dark corrections, estimate the noise, radiometrically calibrate data, and correct stray light. A forward model integrated into the L0–L1B processor is demonstrated to retrieve wavelength shifts during flight accurately. It is also shown to characterize the instrument spectral response function (ISRF) changes occurring at each sampled spatial footprint. We demonstrate fast and accurate orthorectification of MethaneAIR data in a three-step process: (i) initial orthorectification of all observations using aircraft avionics, a simple camera model, and a medium-resolution digital elevation map; (ii) registration of oxygen (O 2 ) channel grayscale images to reference Multispectral Instrument (MSI) band 11 imagery via Accelerated-KAZE (A-KAZE) feature extraction and linear transformation, with similar co-registration of methane (CH 4 ) channel grayscale images to the registered O 2 channel images; and finally (iii) optimization of the aircraft position and attitude to the registered imagery and calculation of viewing geometry. This co-registration technique accurately orthorectifies each channel to the referenced MSI imagery. However, in the pixel domain, radiance data for each channel are offset by almost 150–200 across-track pixels (rows) and need to be aligned for the full-physics or proxy retrievals where both channels are simultaneously used. We leveraged our orthorectification tool to identify tie points with similar geographic locations in both CH 4 and O 2 images in order to produce shift ...
    Subject code 333
    Language English
    Publishing date 2024-02-29
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Book ; Online: Methane retrieval from MethaneAIR using the CO2 Proxy Approach

    Chan Miller, Christopher / Roche, Sebastien / Wilzewksi, Jonas S. / Liu, Xiong / Chance, Kelly / Souri, Amir H. / Conway, Eamon / Luo, Bingkun / Samra, Jenna / Hawthorne, Jacob / Sun, Kang / Staebell, Carly / Chulakadabba, Apisada / Sargent, Maryann / Benmergui, Joshua S. / Franklin, Jonathan E. / Daube, Bruce C. / Li, Yang / Laughner, Joshua L. /
    Baier, Bianca C. / Gautam, Ritesh / Omara, Mark / Wofsy, Steven C.

    eISSN:

    A demonstration for the upcoming MethaneSAT mission

    2023  

    Abstract: Reducing methane (CH 4 ) emissions from the oil and gas (O&G) sector is key to mitigating climate change in the near-term. MethaneSAT is an upcoming satellite mission designed to monitor basin-wide O&G emissions globally, providing estimates of emission ... ...

    Abstract Reducing methane (CH 4 ) emissions from the oil and gas (O&G) sector is key to mitigating climate change in the near-term. MethaneSAT is an upcoming satellite mission designed to monitor basin-wide O&G emissions globally, providing estimates of emission rates and helping identify the underlying processes leading to methane release to the atmosphere. MethaneSAT data will help advocacy and policy efforts to help track methane reduction commitments and targets made by countries and industry. Here we introduce the CH 4 retrieval algorithm for MethaneSAT based on the CO 2 proxy method. We apply the algorithm to observations from the maiden campaign of MethaneAIR, an airborne precursor to the satellite with similar instrument specifications. The campaign was conducted during winter 2019 and summer 2021 over three major US oil and gas basins. Analysis of the MethaneAIR data shows that measurement precision is typically better than 2 % for 20 × 20 m 2 pixel resolution, with no strong dependence on geophysical variables such as surface reflectance. We show that detector focus drifts over the course of each flight likely due to thermal gradients that develop across the optical bench. The impacts of this drift on retrieved CH 4 can mostly be mitigated by including a parameter that squeezes the laboratory tabulated instrument spectral response function in the spectral fit. Validation against coincident EM27/SUN retrievals shows that MethaneAIR values are generally within 1 %. MethaneAIR retrievals were also intercompared with those of TROPOMI; the latitudinal gradients for the two datasets are in good agreement, with a 2.5 ppb mean bias between instruments. We evaluate the accuracy of MethaneAIR estimates of point source emissions using observations made over the Permian O&G basin, based on the integrated mass enhancement approach coupled with a plume-masking algorithm based on total variational denoising. We estimate that the median point source detection threshold is 100–150 kg h −1 at the aircraft’s nominal ...
    Subject code 333
    Language English
    Publishing date 2023-10-06
    Publishing country de
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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