{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T22:19:28Z","timestamp":1775081968243,"version":"3.50.1"},"reference-count":25,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,12,12]],"date-time":"2025-12-12T00:00:00Z","timestamp":1765497600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"JSPS","doi-asserted-by":"publisher","award":["24K00940"],"award-info":[{"award-number":["24K00940"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Future Internet"],"abstract":"<jats:p>Many countries around the world repeatedly suffer from natural disasters such as earthquakes, tsunamis, floods, and hurricanes due to geographical factors, including plate boundaries, tropical cyclone zones, and coastal regions. Representative examples include Hurricane Katrina, which struck the United States in 2005, and the Great East Japan Earthquake in 2011. Both were large-scale disasters that occurred in developed countries and caused enormous human and economic losses regardless of disaster type or location. As the occurrence of such catastrophic events remains inevitable, establishing effective preparedness and rapid response systems for large-scale disasters has become an urgent global challenge. One of the critical issues in disaster response is the rapid estimation of the number of affected individuals required for effective rescue operations. During large-scale disasters, terrestrial communication infrastructure is often rendered unusable, which severely hampers the collection of situational information. If the population within a disaster-affected area can be estimated without relying on ground-based communication networks, rescue resources can be more appropriately allocated based on the estimated number of people in need, thereby accelerating rescue operations and potentially reducing casualties. In this study, we propose a population-estimation system that remotely senses radio signals emitted from smartphones in disaster areas using Low Earth Orbit (LEO) satellites. Through numerical analysis conducted in MATLAB R2023b, the feasibility of the proposed system is examined. The numerical results demonstrate that, under ideal conditions, the proposed system can estimate the number of smartphones within the observation area with an average error of 2.254 devices. Furthermore, an additional evaluation incorporating a 3D urban model demonstrates that the proposed system can estimate the number of smartphones with an average error of 19.03 devices. To the best of our knowledge, this is the first attempt to estimate post-disaster population using wireless LAN signals sensed by LEO satellites, offering a novel remote-sensing-based approach for rapid disaster response.<\/jats:p>","DOI":"10.3390\/fi17120570","type":"journal-article","created":{"date-parts":[[2025,12,12]],"date-time":"2025-12-12T14:04:40Z","timestamp":1765548280000},"page":"570","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Population Estimation and Scanning System Using LEO Satellites Based on Wireless LAN Signals for Post-Disaster Areas"],"prefix":"10.3390","volume":"17","author":[{"given":"Futo","family":"Noda","sequence":"first","affiliation":[{"name":"Institue Science of Tokyo, 2-12-1 Ookayama, Meguro 152-8550, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5190-1085","authenticated-orcid":false,"given":"Gia Khanh","family":"Tran","sequence":"additional","affiliation":[{"name":"Institue Science of Tokyo, 2-12-1 Ookayama, Meguro 152-8550, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,12]]},"reference":[{"key":"ref_1","unstructured":"UNDRR (United Nations Office for Disaster Risk Reduction) (2025, November 03). 2023 Global Assessment Report on Disaster Risk Reduction (GAR 2023): Mapping Resilience for the Sustainable Development Goals; United Nations Office for Disaster Risk Reduction: ISBN 978-92-1-200283-01. Available online: https:\/\/www.undrr.org\/publication\/2023-global-assessment-report-disaster-risk-reduction."},{"key":"ref_2","unstructured":"Ministry of Internal Affairs and Communications, Japan (2025, November 03). White Paper on Information and Communications (FY 2011). Available online: https:\/\/www.soumu.go.jp\/johotsusintokei\/whitepaper\/ja\/h23\/html\/nc111100.html."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"711","DOI":"10.52953\/LWXC1928","article-title":"Leo satellite networking relaunched: Survey and current research challenges","volume":"10","author":"Westphal","year":"2023","journal-title":"ITU J. Future Evol. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Bardeloza, D.K., Libatique, N.J., Tangonan, G.L., Vicente, M.C.T., and Honrado, J.L. (2019, January 17\u201320). Towards Vulnerability Mapping on High Resolution Aerial Images: Roof Detection, GIS, and Machine Learning Techniques. Proceedings of the 2019 IEEE Global Humanitarian Technology Conference (GHTC), Seattle, WA, USA.","DOI":"10.1109\/GHTC46095.2019.9033030"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Jnr, O.W.B., Agomuo, O.C., and Muzamal, J.H. (2024, January 25\u201327). Adaptive Multi-Layered Non-Terrestrial Network with Integrated FSO and RF Communications for Enhanced Global Connectivity. Proceedings of the 2024 IEEE\/ACIS 27th International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel\/Distributed Computing (SNPD), Beijing, China.","DOI":"10.1109\/SNPD61259.2024.10673951"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Ko\u00e7, G.B., and Ozturk, M. (May, January 28). Score-Based Allocation Method for Post-Disaster Communications via Multi-Layer NTN Architecture. Proceedings of the 2025 33rd Signal Processing and Communications Applications Conference (SIU), \u015eile, Istanbul, T\u00fcrkiye.","DOI":"10.1109\/SIU66497.2025.11112392"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Noda, F., and Tran, G.K. (2024, January 6\u20139). Proposal of LEO-Based Population Estimation System Using Smartphone Emitted WLAN Signals. Proceedings of the 2024 IEEE 21st Consumer Communications & Networking Conference (CCNC), Las Vegas, NV, USA.","DOI":"10.1109\/CCNC51664.2024.10454793"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Nawawi, L.H., Khalifa, O.O., Rahman, F.A., and Nasir, H. (2019, January 27\u201329). Location and Position Estimation of Wireless Devices. Proceedings of the 2019 IEEE International Conference on Smart Instrumentation, Measurement and Application (ICSIMA), Kuala Lumpur, Malaysia.","DOI":"10.1109\/ICSIMA47653.2019.9057298"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Andong, S., and Yamamoto, H. (2019, January 11\u201313). Victim Detection System Using Autonomous UAV Flight and Data Analysis Based on Multiple Beacon Radio Sensing. Proceedings of the 2019 International Conference on Artificial Intelligence in Information and Communication (ICAIIC), Okinawa, Japan.","DOI":"10.1109\/ICAIIC.2019.8668991"},{"key":"ref_10","first-page":"13","article-title":"Development and Evaluation of Victim Detection System Using Autonomous UAV Flight Based on Beacon Radio Sensing","volume":"117","author":"Andong","year":"2017","journal-title":"IEICE Tech. Rep."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Liu, X., Zhu, X., Pan, Y., Ma, Y., Li, T., and Chen, S. (2015, January 26\u201331). Mapping Population Distribution by Integrating Night-Time Light Satellite Imagery and Land-Cover Data. Proceedings of the 2015 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Milan, Italy.","DOI":"10.1109\/IGARSS.2015.7326238"},{"key":"ref_12","first-page":"7","article-title":"Capacity Evaluation for IoT Terminals in LEO Satellite IoT Platform Using Receiver Beamforming with Doppler Rate Compensation","volume":"123","author":"Sakamoto","year":"2023","journal-title":"IEICE Tech. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"696","DOI":"10.1109\/LCOMM.2020.3037351","article-title":"On Modeling Satellite-to-Ground Path-Loss in Urban Environments","volume":"25","author":"Guvenc","year":"2021","journal-title":"IEEE Commun. Lett."},{"key":"ref_14","unstructured":"Crisp, N.H., Livadotti, S., and Roberts, P.C.E. (2018). A Semi\u2013Analytical Method for Calculating Revisit Time for Satellite Constellations with Discontinuous Coverage. arXiv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2204","DOI":"10.1109\/LWC.2025.3566489","article-title":"Joint Attitude and Precoding Optimization for LEO Satellite MIMO Communication Systems","volume":"14","author":"Hui","year":"2025","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_16","unstructured":"Ministry of Internal Affairs and Communications, Japan (2025, November 03). 2023 White Paper on Information and Communications. p. 137. Available online: https:\/\/www.soumu.go.jp\/johotsusintokei\/whitepaper\/ja\/r05\/pdf\/00zentai.pdf."},{"key":"ref_17","unstructured":"Ministry of Internal Affairs and Communications, Japan (2025, November 03). On the Outdoor Use of Wireless LAN. Available online: https:\/\/www.tele.soumu.go.jp\/j\/sys\/others\/wlan_outdoor\/."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"7217","DOI":"10.1109\/TAP.2017.2765541","article-title":"A Simplified Model to Predict Oxygen Attenuation on Earth\u2013Space Links","volume":"65","author":"Luini","year":"2017","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Tomura, T., Sakamoto, H., and Fukao, T. (April, January 30). C-Band Stretchable-Substrate-Impregnated Fabric Origami Deployable Reflectarray Antennas for Small Satellites. Proceedings of the 2025 19th European Conference on Antennas and Propagation (EuCAP), Stockholm, Sweden.","DOI":"10.23919\/EuCAP63536.2025.10999627"},{"key":"ref_20","unstructured":"(2021). IEEE Standard for Information Technology\u2014Telecommunications and Information Exchange between Systems\u2014Local and Metropolitan Area Networks\u2014Specific Requirements\u2014Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications\u2014Redline (Standard No. IEEE Std. 802.11-2020 (Revision of IEEE Std. 802.11-2016)\u2014Redline)."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Tran, G.K. (2024, January 2\u20135). A Study on Throughput Coverage Evaluation of Non-Terrestrial Communication Base Stations. Proceedings of the 2024 Fifteenth International Conference on Ubiquitous and Future Networks (ICUFN), Budapest, Hungary.","DOI":"10.1109\/ICUFN61752.2024.10625638"},{"key":"ref_22","unstructured":"The Institute of Electronics, Information and Communication Engineers (IEICE) (1980). Antenna Engineering Handbook, IEICE."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1109\/JRPROC.1946.234568","article-title":"A Note on a Simple Transmission Formula","volume":"34","author":"Friis","year":"1946","journal-title":"Proc. IRE"},{"key":"ref_24","unstructured":"Balanis, C. (2016). Antenna Theory: Analysis and Design, John Wiley & Sons."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Kang, E., Park, Y., Kim, J., and Choo, H. (2024). Downlink Analysis of a Low-Earth Orbit Satellite Considering an Airborne Interference Source Moving on Various Trajectory. Remote Sens., 16.","DOI":"10.3390\/rs16020321"}],"container-title":["Future Internet"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1999-5903\/17\/12\/570\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,17]],"date-time":"2025-12-17T08:39:05Z","timestamp":1765960745000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1999-5903\/17\/12\/570"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,12]]},"references-count":25,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["fi17120570"],"URL":"https:\/\/doi.org\/10.3390\/fi17120570","relation":{},"ISSN":["1999-5903"],"issn-type":[{"value":"1999-5903","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,12]]}}}