Sensing the living airspace: city-wide bird flight patterns revealed by communication networks

Sensing the living airspace: city-wide bird flight patterns revealed by communication networks | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Sensing the living airspace: city-wide bird flight patterns revealed by communication networks Jiachen Wei, Zhiyong Feng, Dingyou Ma, Qixun Zhang, Kan Yu, Ningyan Guo, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7964150/v2 This work is licensed under a CC BY 4.0 License Status: Posted Version 2 posted You are reading this latest preprint version Show more versions Abstract Monitoring low-altitude bird movement is crucial for ecological research and aviation safety, yet a critical data gap exists due to the limitations of conventional radar and sparse sensor coverage in urban environments. Here, we demonstrate that existing cellular communication networks can be repurposed as a dense, city-scale biosensor network to fill this gap. We deploy a sub-6 GHz integrated sensing and communication (ISAC) system using two base stations (BSs), featuring a novel frame design that reserves only 1.4% of resources for sensing, thus maintaining uninterrupted communication services. To extract the weak micro-Doppler signal of birds from heavy urban interference, we develop a two-stage signal processing pipeline that recovers their characteristic micro-Doppler signatures. Using this system, we collect and analyze a large-scale dataset of \(\:110\hspace{0.25em}GB\) from hundreds of free-flying pigeons. Analysis of these signals first reveals significant variability in the time-frequency domain across individuals, a direct result of differences in their body size, flight posture, and angle relative to the BS. Despite this individual-level diversity, we extract a unifying biomechanical signature that represents a population-level commonality, providing a new layer of ecological information: a stable and consistent wingbeat frequency distribution for pigeons, with a mean of \(\:6.42\hspace{0.25em}Hz\) and a variance of \(\:1.55\hspace{0.25em}H{z}^{2}\). We show that this signature serves as a robust feature to distinguish birds from other aerial targets, such as unmanned aerial vehicles (UAVs), and we integrate it into a multi-station framework to map continuous, city-scale flight trajectories. Our work provides a practical pathway for transforming ubiquitous cellular infrastructure into a global tool for large-scale ecological monitoring and the mitigation of human-wildlife conflicts. Integrated sensing and communication Bird micro-Doppler Bird Monitoring Urban ecology Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 2 posted You are reading this latest preprint version Show more versions Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7964150","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":540890129,"identity":"546cb838-0e6a-4de4-aad9-035ff4c92f2b","order_by":0,"name":"Jiachen Wei","email":"","orcid":"","institution":"Beijing University of Posts and Telecommunications","correspondingAuthor":false,"prefix":"","firstName":"Jiachen","middleName":"","lastName":"Wei","suffix":""},{"id":540890130,"identity":"737950ad-ce7a-4fc8-8375-4dee02608bf2","order_by":1,"name":"Zhiyong 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Here, we demonstrate that existing cellular communication networks can be repurposed as a dense, city-scale biosensor network to fill this gap. We deploy a sub-6 GHz integrated sensing and communication (ISAC) system using two base stations (BSs), featuring a novel frame design that reserves only 1.4% of resources for sensing, thus maintaining uninterrupted communication services. To extract the weak micro-Doppler signal of birds from heavy urban interference, we develop a two-stage signal processing pipeline that recovers their characteristic micro-Doppler signatures. Using this system, we collect and analyze a large-scale dataset of \\(\\:110\\hspace{0.25em}GB\\) from hundreds of free-flying pigeons. Analysis of these signals first reveals significant variability in the time-frequency domain across individuals, a direct result of differences in their body size, flight posture, and angle relative to the BS. 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