2025/02/27 by Hao-Hui 浩辉 Zhang 张, Zhang, Hao-Hui, Xue, Wang-Chen +17
Earth and Planetary Sciences · Physics and Astronomy · #Atmospheric and Oceanic Physics (physics.ao-ph) #Earth and Planetary Astrophysics (astro-ph.EP) #Earthquake Detection and Analysis #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Ionosphere and magnetosphere dynamics #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2502.19678
openalex publication_date 2025/02/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The density of the Earth's middle and upper atmosphere is an important question in Earth science and is a critical factor in the design, operation, and orbital determination of low Earth orbit spacecraft. In this study, we employ the Earth Occultation Technique (EOT) combined with Maximum Likelihood Estimation to estimate the neutral atmospheric density by modeling the attenuation of X-ray photons during the occultation process of Insight-HXMT observations of Crab Nebula. Based on 83 occultation datasets of the Crab Nebula observed by all three sets of telescopes of Insight-HXMT between 2022 and 2024, we derived the atmospheric densities at altitudes ranging from 55 --130 km. We find a general agreement between our results and the prediction by the NRLMSIS model within the altitude ranges of 65 -- 90 km, 95 --100 km and 120 --130 km, particularly during periods of enhanced solar activity. However, we also find that the NRLMSIS model overestimates atmospheric density at altitudes 90 --95 km and 100 --120 km by approximately 20%. Furthermore, since the atmospheric density measurements at altitudes of 55 -- 65 km may be subject to selection bias, we do not report the prediction accuracy of the NRLMSIS model at this altitude.