{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,2]],"date-time":"2026-03-02T18:46:49Z","timestamp":1772477209508,"version":"3.50.1"},"reference-count":25,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2023,4,22]],"date-time":"2023-04-22T00:00:00Z","timestamp":1682121600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Research and Development Program of China","award":["2022YFE0102600"],"award-info":[{"award-number":["2022YFE0102600"]}]},{"name":"National Key Research and Development Program of China","award":["2016YFB0502102"],"award-info":[{"award-number":["2016YFB0502102"]}]},{"name":"National Key Research and Development Program of China","award":["CSC 202106420051"],"award-info":[{"award-number":["CSC 202106420051"]}]},{"name":"China Sponsorship Council","award":["2022YFE0102600"],"award-info":[{"award-number":["2022YFE0102600"]}]},{"name":"China Sponsorship Council","award":["2016YFB0502102"],"award-info":[{"award-number":["2016YFB0502102"]}]},{"name":"China Sponsorship Council","award":["CSC 202106420051"],"award-info":[{"award-number":["CSC 202106420051"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Accurate altimetry is essential for location-based services in commercial and industrial applications. However, current altimetry methods only provide low-accuracy measurements, particularly in multistorey buildings with irregular structures, such as hollow areas found in various industrial and commercial sites. This paper innovatively proposes a tightly coupled indoor altimetry system that utilizes floor identification to improve height measurement accuracy. The system includes two optimized algorithms that improve floor identification accuracy through activity detection and address the problem of difficult convergence of z-axis coordinates due to indoor coplanarity by applying constraints to iterative least squares (ILS). Two experiments were conducted in a teaching building and a laboratory, including an irregular environment with a hollow area. The results show that our proposed method for identifying floors based on activity detection outperforms other methods. In dynamic experiments, our method effectively eliminates repeated transformations during the up- and downstairs process, and in static experiments, it minimizes the impact of barometric drift. Furthermore, our proposed altimetry method based on constrained ILS achieves significantly improved positioning accuracy compared to ILS, 1D-CNN, and WC. Specifically, in the teaching building, our method achieves improvements of 0.84 m, 0.288 m, and 0.248 m, respectively, while in the laboratory, the improvements are 2.607 m, 0.696 m, and 0.625 m.<\/jats:p>","DOI":"10.3390\/s23094180","type":"journal-article","created":{"date-parts":[[2023,4,24]],"date-time":"2023-04-24T03:04:08Z","timestamp":1682305448000},"page":"4180","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["A Hybrid Indoor Altimetry Based on Barometer and UWB"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6581-4708","authenticated-orcid":false,"given":"Minghao","family":"Si","sequence":"first","affiliation":[{"name":"Key Laboratory for Land Environment and Disaster Monitoring, China University of Mining and Technology, Xuzhou 221116, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1903-242X","authenticated-orcid":false,"given":"Yunjia","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory for Land Environment and Disaster Monitoring, China University of Mining and Technology, Xuzhou 221116, China"}]},{"given":"Ning","family":"Zhou","sequence":"additional","affiliation":[{"name":"Chinese Academy of Surveying and Mapping, Beijing 100036, China"}]},{"given":"Cheekiat","family":"Seow","sequence":"additional","affiliation":[{"name":"School of Computing Science, University of Glasgow, Glasgow G12 8RZ, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1371-2683","authenticated-orcid":false,"given":"Harun","family":"Siljak","sequence":"additional","affiliation":[{"name":"School of Engineering, Trinity College Dublin, The University of Dublin, D02 PN40 Dublin, Ireland"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Xu, S., Wang, Y., and Si, M. 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