{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,31]],"date-time":"2025-10-31T08:07:53Z","timestamp":1761898073264,"version":"build-2065373602"},"reference-count":47,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T00:00:00Z","timestamp":1761696000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100030861","name":"COMPETE 2020","doi-asserted-by":"crossref","award":["POCI-01-0247-FEDER-041435"],"award-info":[{"award-number":["POCI-01-0247-FEDER-041435"]}],"id":[{"id":"10.13039\/100030861","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Portugal 2020","award":["POCI-01-0247-FEDER-046103"],"award-info":[{"award-number":["POCI-01-0247-FEDER-046103"]}]},{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","award":["UIDB\/50014\/2020"],"award-info":[{"award-number":["UIDB\/50014\/2020"]}]},{"name":"Google Cloud Research Credits program"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Indoor Positioning Systems (IPSs) are essential for applications requiring accurate location awareness in indoor environments. However, achieving high precision remains challenging due to signal interference and environmental variability. This study proposes a multimodal IPS that integrates Bluetooth Received Signal Strength Indicator (RSSI) measurements and video imagery using machine learning (ML) and ensemble learning techniques. The system was implemented and deployed in the Hall of Biodiversity at the Natural History and Science Museum of the University of Porto. The venue presented significant deployment issues, namely restrictions on beacon placement and lighting conditions. We trained independent ML models on RSSI and video datasets, and combined them through ensemble learning methods. The experimental results from test scenarios, which included simulated visitor trajectories, showed that ensemble models consistently outperformed the RSSI-based and video-based models. These findings demonstrate that the use of multimodal data can significantly improve IPS accuracy despite constraints such as multipath interference, low lighting, and limited beacon infrastructure. Overall, they highlight the potential of multimodal data for deployments in complex indoor environments.<\/jats:p>","DOI":"10.3390\/s25216640","type":"journal-article","created":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T03:44:39Z","timestamp":1761795879000},"page":"6640","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Machine Learning Models for Indoor Positioning Using Bluetooth RSSI and Video Data: A Case Study"],"prefix":"10.3390","volume":"25","author":[{"given":"Tom\u00e1s","family":"Mamede","sequence":"first","affiliation":[{"name":"Department of Computer Science, Faculty of Sciences, University of Porto, Rua do Campo Alegre 1055, 4169-007 Porto, Portugal"}]},{"given":"Nuno","family":"Silva","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Faculty of Sciences, University of Porto, Rua do Campo Alegre 1055, 4169-007 Porto, Portugal"}]},{"given":"Eduardo R. B.","family":"Marques","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Faculty of Sciences, University of Porto, Rua do Campo Alegre 1055, 4169-007 Porto, Portugal"},{"name":"INESC TEC, Campus da Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8273-1357","authenticated-orcid":false,"given":"Lu\u00eds M. B.","family":"Lopes","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Faculty of Sciences, University of Porto, Rua do Campo Alegre 1055, 4169-007 Porto, Portugal"},{"name":"INESC TEC, Campus da Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"100608","DOI":"10.1016\/j.iot.2022.100608","article-title":"A Survey of Indoor Location Technologies, Techniques and Applications in Industry","volume":"20","author":"Hayward","year":"2022","journal-title":"Internet Things"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2568","DOI":"10.1109\/COMST.2019.2911558","article-title":"A survey of indoor localization systems and technologies","volume":"21","author":"Zafari","year":"2019","journal-title":"IEEE Commun. Surv. 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