Détail de l'auteur
Auteur Nobusuke Iwasaki |
Documents disponibles écrits par cet auteur (3)



Quality assessment of volunteered geographic information for outdoor activities: an analysis of OpenStreetMap data for names of peaks in Japan / Jun Yamashita in Geo-spatial Information Science, vol 26 n° inconnu ([01/08/2023])
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Titre : Quality assessment of volunteered geographic information for outdoor activities: an analysis of OpenStreetMap data for names of peaks in Japan Type de document : Article/Communication Auteurs : Jun Yamashita, Auteur ; Toshikazu Seto, Auteur ; Nobusuke Iwasaki, Auteur ; Yuichiro Nishimura, Auteur Année de publication : 2023 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] données localisées des bénévoles
[Termes IGN] Japon
[Termes IGN] montagne
[Termes IGN] OpenStreetMap
[Termes IGN] oronymie
[Termes IGN] qualité des donnéesRésumé : (auteur) Geographical studies of outdoor activities have increased in recent years with the rise in popularity of these activities worldwide, including in Japan. Volunteered geographic information (VGI) is a key tool for organizing outdoor activities as it offers a means to determine the locational information and names of places. To evaluate the quality of VGI, geospatial data generated by land survey agencies and other VGI are often utilized as reference data. However, since these reference data may not be available, other methods are necessary to assure the quality of VGI. In this study, we examined five trust indicators based on the inherent characteristics of VGI through an empirical case study. We used mountain names extracted from OpenStreetMap in Japan as data because there were almost no other VGI in the vicinity. As a result, we isolated three trust indicators, namely versions, users, and tag corrections, to examine the thematic accuracy of VGI because these were the only statistically significant indicators. However, we found that the prediction rate of thematic accuracy was very low. To improve thematic accuracy, this study recommends using the most accurate versions, applying correctly given tags, and considering the motivations and characteristics of the VGI contributors. Numéro de notice : A2022-611 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10095020.2022.2085188 Date de publication en ligne : 01/07/2022 En ligne : https://doi.org/10.1080/10095020.2022.2085188 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101365
in Geo-spatial Information Science > vol 26 n° inconnu [01/08/2023][article]Alternative procedure to improve the positioning accuracy of orthomosaic images acquired with Agisoft Metashape and DJI P4 multispectral for crop growth observation / Toshihiro Sakamoto in Photogrammetric Engineering & Remote Sensing, PERS, vol 88 n° 5 (May 2022)
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Titre : Alternative procedure to improve the positioning accuracy of orthomosaic images acquired with Agisoft Metashape and DJI P4 multispectral for crop growth observation Type de document : Article/Communication Auteurs : Toshihiro Sakamoto, Auteur ; Daisuke Ogawa, Auteur ; Satoko Hiura, Auteur ; Nobusuke Iwasaki, Auteur Année de publication : 2022 Article en page(s) : pp 323 - 332 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] bande spectrale
[Termes IGN] blé (céréale)
[Termes IGN] chlorophylle
[Termes IGN] image à haute résolution
[Termes IGN] image captée par drone
[Termes IGN] indice de végétation
[Termes IGN] orthophotoplan numérique
[Termes IGN] point d'appui
[Termes IGN] précision du positionnement
[Termes IGN] rizière
[Termes IGN] structure-from-motionRésumé : (Auteur) Vegetation indices (VIs), such as the green chlorophyll index and normalized difference vegetation index, are calculated from visible and near-infrared band images for plant diagnosis in crop breeding and field management. The DJI P4 Multispectral drone combined with the Agisoft Metashape Structure from Motion/Multi View Stereo software is some of the most cost-effective equipment for creating high-resolution orthomosaic VI images. However, the manufacturer's procedure results in remarkable location estimation inaccuracy (average error: 3.27–3.45 cm) and alignment errors between spectral bands (average error: 2.80–2.84 cm). We developed alternative processing procedures to overcome these issues, and we achieved a higher positioning accuracy (average error: 1.32–1.38 cm) and better alignment accuracy between spectral bands (average error: 0.26–0.32 cm). The proposed procedure enables precise VI analysis, especially when using the green chlorophyll index for corn, and may help accelerate the application of remote sensing techniques to agriculture. Numéro de notice : A2022-528 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14358/PERS.21-00064R2 Date de publication en ligne : 01/05/2022 En ligne : https://doi.org/10.14358/PERS.21-00064R2 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101379
in Photogrammetric Engineering & Remote Sensing, PERS > vol 88 n° 5 (May 2022) . - pp 323 - 332[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 105-2022052 SL Revue Centre de documentation Revues en salle Disponible 105-2022051 SL Revue Centre de documentation Revues en salle Disponible VGI contributors’ awareness of geographic information quality and its effect on data quality: a case study from Japan / Jun Yamashita in International journal of cartography, vol 5 n° 2-3 (July - November 2019)
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Titre : VGI contributors’ awareness of geographic information quality and its effect on data quality: a case study from Japan Type de document : Article/Communication Auteurs : Jun Yamashita, Auteur ; Toshikazu Seto, Auteur ; Yuichiro Nishimura, Auteur ; Nobusuke Iwasaki, Auteur Année de publication : 2019 Conférence : ICC 2019, 29th International Cartographic Conference ICA, Mapping everything for everyone 15/07/2019 20/07/2019 Tokyo Japon Open Access Proceedings of the ICA Article en page(s) : pp 214 - 224 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] cartographie collaborative
[Termes IGN] contributeur
[Termes IGN] données localisées des bénévoles
[Termes IGN] fiabilité des données
[Termes IGN] Japon
[Termes IGN] OpenStreetMap
[Termes IGN] précision des données
[Termes IGN] production participative
[Termes IGN] qualité des connaissancesRésumé : (Auteur) In many countries, geospatial data are typically provided by public institutions. Cities have been mapped using such public data. On the other hand, the demand for geospatial data has been diversifying, given the requirements for mapping cities. To respond to demands for new geospatial data, creation of citizen-generated open data and volunteered geographic information (VGI) have recently become popular. However, the quality of such open data and VGI are not always guaranteed. The number of studies on quality assessments of VGI have increased in recent years. The present study aimed to identify OpenStreetMap (OSM), one type of VGI, as well as contributors’ awareness of data quality, and the relationships between their awareness and the positional accuracy of the OSM data contributed by them. The results showed that awareness or lack of the positional accuracy did not affect the quality of the OSM data created by the contributors. These findings suggest that the crowdsourcing approach might not guarantee the data quality of VGI. Numéro de notice : A2019-238 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/23729333.2019.1613086 Date de publication en ligne : 17/05/2019 En ligne : https://doi.org/10.1080/23729333.2019.1613086 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92938
in International journal of cartography > vol 5 n° 2-3 (July - November 2019) . - pp 214 - 224[article]