{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T21:09:39Z","timestamp":1781298579303,"version":"3.54.1"},"reference-count":46,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2024,9,5]],"date-time":"2024-09-05T00:00:00Z","timestamp":1725494400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sichuan Natural Science Foundation (General Program)","award":["2024NSFSC0176"],"award-info":[{"award-number":["2024NSFSC0176"]}]},{"name":"Sichuan Natural Science Foundation (General Program)","award":["62371014"],"award-info":[{"award-number":["62371014"]}]},{"name":"Sichuan Natural Science Foundation (General Program)","award":["4222002"],"award-info":[{"award-number":["4222002"]}]},{"name":"National Natural Science Foundation of China","award":["2024NSFSC0176"],"award-info":[{"award-number":["2024NSFSC0176"]}]},{"name":"National Natural Science Foundation of China","award":["62371014"],"award-info":[{"award-number":["62371014"]}]},{"name":"National Natural Science Foundation of China","award":["4222002"],"award-info":[{"award-number":["4222002"]}]},{"name":"Beijing Natural Science Foundation","award":["2024NSFSC0176"],"award-info":[{"award-number":["2024NSFSC0176"]}]},{"name":"Beijing Natural Science Foundation","award":["62371014"],"award-info":[{"award-number":["62371014"]}]},{"name":"Beijing Natural Science Foundation","award":["4222002"],"award-info":[{"award-number":["4222002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>With the rapid development of space\u2013air\u2013ground integrated networks (SAGIN), the synergy between the satellite and unmanned aerial vehicles (UAVs) in sensing environmental status information reveals substantial potential. In SAGIN, applications such as disaster response and military operations require fresh status information to respond effectively. The freshness of information, quantified by the age of information (AoI) metric, is crucial for an effective response. Therefore, it is urgent to investigate the AoI in real-time remote sensing systems leveraging satellite\u2013UAV synergy. To this end, we first establish a comprehensive system model, corresponding to the satellite\u2013UAV \u201cmultiscale explanation\u201d synergy remote sensing system in SAGIN, in which we focus on the typical information transmission and fusion strategies of the system, the analysis framework of AoI, and the temporal evolution of AoI. Subsequently, the time-varying process of the system model is transformed into a corresponding finite-states continuous-time Markov chain, enabling a precise analysis of its stochastic behavior. By employing the stochastic hybrid system (SHS) approach, the moment generating functions (MGFs) and mean AoI, offering quantitative insights into the freshness of status information, are derived. Following this, a comparative analysis of AoI under different queuing disciplines, highlighting their respective performance characteristics, is conducted. Furthermore, considering transmit power and bandwidth constraints of the system, the AoI performances under full frequency reuse (FFR), and frequency division multiple access (FDMA) strategies are analyzed. The energy advantage and spectrum advantage associated with AoI are also examined to explore the superior AoI-related performance of the FFR strategy in SAGIN.<\/jats:p>","DOI":"10.3390\/rs16173305","type":"journal-article","created":{"date-parts":[[2024,9,5]],"date-time":"2024-09-05T11:15:59Z","timestamp":1725534959000},"page":"3305","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["AoI Analysis of Satellite\u2013UAV Synergy Real-Time Remote Sensing System"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-5480-2319","authenticated-orcid":false,"given":"Libo","family":"Wang","sequence":"first","affiliation":[{"name":"School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu 611731, China"},{"name":"Aircraft Swarm Intelligent Sensing and Cooperative Control Key Laboratory of Sichuan Province, Chengdu 611731, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiangyin","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu 611731, China"},{"name":"Aircraft Swarm Intelligent Sensing and Cooperative Control Key Laboratory of Sichuan Province, Chengdu 611731, China"},{"name":"National Laboratory on Adaptive Optics, Chengdu 611731, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaiyu","family":"Qin","sequence":"additional","affiliation":[{"name":"School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu 611731, China"},{"name":"Aircraft Swarm Intelligent Sensing and Cooperative Control Key Laboratory of Sichuan Province, Chengdu 611731, China"},{"name":"National Laboratory on Adaptive Optics, Chengdu 611731, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2880-3329","authenticated-orcid":false,"given":"Zhuwei","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Information Science and Technology, Beijing University of Technology, Beijing 100124, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiayi","family":"Zhou","sequence":"additional","affiliation":[{"name":"School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu 611731, China"},{"name":"Aircraft Swarm Intelligent Sensing and Cooperative Control Key Laboratory of Sichuan Province, Chengdu 611731, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Deyu","family":"Song","sequence":"additional","affiliation":[{"name":"School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu 611731, China"},{"name":"Aircraft Swarm Intelligent Sensing and Cooperative Control Key Laboratory of Sichuan Province, Chengdu 611731, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1109\/MWC.2019.1800298","article-title":"Compressed robust transmission for remote sensing services in space information networks","volume":"26","author":"Lu","year":"2019","journal-title":"IEEE Wirel. 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