{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T05:00:23Z","timestamp":1790312423066,"version":"4.1.0"},"reference-count":34,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T00:00:00Z","timestamp":1790121600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004543","name":"China Scholarship Council","doi-asserted-by":"publisher","award":["202106260030"],"award-info":[{"award-number":["202106260030"]}],"id":[{"id":"10.13039\/501100004543","id-type":"DOI","asserted-by":"publisher"}]},{"award":["202106260030"],"award-info":[{"award-number":["202106260030"]}],"id":[{"id":"https:\/\/ror.org\/04atp4p48","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Accurate motion estimation and online camera orientation calibration are important for onboard vision systems on ground vehicles. Ground-view sensing is attractive for these tasks because the ground is typically static, close to the vehicle, and continuously observable, but fast ground-relative motion requires high-temporal-resolution sensing. This paper presents a unified framework that uses a ground-view event camera to estimate ground-view camera motion and support online orientation calibration of a target vehicle-mounted camera. The event camera provides high temporal resolution with sparse measurements, making it suitable for fast ground-view sensing. The framework couples online event-based ground-view motion estimation with an improved calibration process, allowing the estimated motion to support calibration and be further refined during calibration. Specifically, ground-view motion is first estimated online from short event windows using a spiking neural network, providing direct short-term motion information from the event stream. The estimated motion is then integrated with target-camera motion and geometric constraints to estimate the target-camera orientation while further refining the ground-view motion. Experiments on real-vehicle data show accurate ground-view motion estimation, improved rotational components through motion refinement, and better target-camera orientation calibration, especially in yaw, while improvements in pitch and roll are less pronounced. These results demonstrate the effectiveness of integrating event-camera-based ground-view motion estimation and online target-camera orientation calibration for ground vehicles.<\/jats:p>","DOI":"10.3390\/s26196032","type":"journal-article","created":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T14:03:26Z","timestamp":1790172206000},"page":"6032","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Unified Framework for Motion Estimation and Online Camera Orientation Calibration Using a Ground-View Event Camera"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6293-1025","authenticated-orcid":false,"given":"Junzhe","family":"Su","sequence":"first","affiliation":[{"name":"The Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-4544-1955","authenticated-orcid":false,"given":"Masahiro","family":"Hirano","sequence":"additional","affiliation":[{"name":"The Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2880-7055","authenticated-orcid":false,"given":"Yuji","family":"Yamakawa","sequence":"additional","affiliation":[{"name":"The Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"107867","DOI":"10.1109\/ACCESS.2023.3320280","article-title":"A Cost-Effective and Highly Accurate Observer for the Real-Time Estimation of the Vehicle Velocity and the Road Inclination and Bank Angles","volume":"11","author":"Papagiannis","year":"2023","journal-title":"IEEE Access"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1109\/JAS.2017.7510811","article-title":"Vehicle dynamic state estimation: State of the art schemes and perspectives","volume":"5","author":"Guo","year":"2018","journal-title":"IEEE\/CAA J. 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