Passive Observation of Martian Atmosphere Using O₂(<i>a</i> ¹Δ<i> _g </i>) Airglow Radiation: Forward Simulation and Wind Retrieval

The passive monitoring of Martian wind fields is crucial for deciphering the Martian atmosphere. With the 3 strong spectral lines in the 1.27 μm O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>(<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</i><sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup>Δ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>g</i></sub>) airglow emission band, this article designs the Martian Static Wind Imaging Michelson Interferometer (M-SWIMI) to measure the atmospheric profiles within the altitude range of 10–50 km. Specifically, a forward model to simulate the entire process from the emission transmission through the Martian atmosphere to the eventual formation of the images observed by the instrument is developed. In addition, a robust retrieval algorithm with the bidirectional smoothing (BS) regularization and the multispectral consistency (MC) constraint is proposed. The BSMC algorithm leverages the smoothness of atmospheric parameters in both horizontal and vertical directions and exploits the inherent correlations among different spectral lines, ensuring the accuracy of Volume Emission Rates (VER), temperature and wind. Experimental results demonstrate the superior noise robustness of the retrieval algorithm, supported by comprehensive ablation studies and performance assessments under various noise scenarios, thereby validating the efficacy of the proposed approach in the study of Martian atmospheric dynamics.