Light & Engineering 34 (2) 2026

Volume 34 (2)
Pages 19–27

Synthetic Study of a Surrogate-Model-Based CO2/CH4 Retrieval Algorithm from Infrared Reflectance Measurements L&E, Vol.34, No.2, 2026

Articles authors:

Handeul Son, Philipp Hochstaffl, Dmitry S. Efremenko

Handeul Son received his M. Sc. degree in Earth Oriented Space Science and Technology (ESPACE) from the Technical University of Munich (TUM) in 2024. Since May 2025, he is a Ph. D. student at TUM and conducts his research at the German Aerospace Centre, focusing on the development of a fast radiative transfer model for infrared spectral simulations. His research interests include radiative transfer modelling, atmospheric remote sensing, and efficient computational methods for inverse problems

Philipp Hochstaffl received his Ph. D. in Meteorology from Ludwig-Maximilians-Universität Munich in 2022. Since 2020, he has been a research associate at the German Aerospace Centre (DLR); from 2016 to 2020 he held a DLRDAAD Research Fellowship. His research focuses on atmospheric remote sensing using radiative transfer modelling and inversion methods. He contributes to mission reports, validation activities, international symposia and has published in multiple peer-reviewed journals and conference proceedings. His broader interests include machine learning, software engineering, exoplanets, and aerospace related topics

Dmitry S. Efremenko, Doctor of Technical Sciences, Corresponding Member of the Academy of Electro-technical Sciences, RF. He graduated from MPEI in 2009, Research scientist, Associate Professor. In 2017, he received the Elsevier/JQSRT Goody Award, he has more than 80 scientific papers in the field of radiation transfer theory

Abstract:

Simulating the solar radiation spectrum reflected by the Earth atmosphere for trace gas retrievals, such as CO2 and CH4, typically involves solving the radiative transfer equation (RTE), a computationally intensive process due to the multiple scattering term.
To accelerate computations, we utilize a fast Python-based radiative transfer model FALCAS that approximates multiple scattering by introducing a virtual layer with isotropic scattering. This allows to mimic the results of the models with full multiple scattering treatment, yet to significantly reduce computation time.
We develop an algorithm for retrieving CO2 and CH4 concentrations using FALCAS and evaluate its accuracy against a discrete ordinate model PYDOME. The CO2 and CH4 retrievals are performed using FALCAS from synthetic spectra generated by PYDOME in the (1500–1750) nm spectral range, considering various aerosol and geometric conditions.
The error in retrieved concentrations is about 2.0 % for the aerosol optical thickness of about 0.9. This result remains robust under noise and convolution effects as well as across varying geometries, with errors under 5 % at a signal-to-noise ratio of 50.

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Keywords

DOI: https://doi.org/10.33383/2025-042

Article in RUS:
Svetotekhnika # 6, 2025, pp. 85–90

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