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GEBCO Gridded Bathymetric Datasets for mapping Japan Trench geomorphology by means of GMT scripting toolset / Polina Lemenkova in Geodesy and cartography, vol 46 n° 3 (October 2020)  

Public [article]  inGeodesy and cartography > vol 46 n° 3 (October 2020) . - pp 98 - 112 Titre : GEBCO Gridded Bathymetric Datasets for mapping Japan Trench geomorphology by means of GMT scripting toolset Type de document : Article/Communication Auteurs : Polina Lemenkova, Auteur Année de publication : 2020 Article en page(s) : pp 98 - 112 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique [Termes IGN] carte bathymétrique [Termes IGN] déformation de la croute terrestre [Termes IGN] données bathymétriques [Termes IGN] données maillées [Termes IGN] geoïde marin [Termes IGN] géomorphologie [Termes IGN] GMT [Termes IGN] Japon [Termes IGN] modèle numérique de surface [Termes IGN] Pacifique (océan) Résumé : (auteur) The study investigated geomorphology of the Japan Trench located east of Japan, Pacific Ocean. A high-resolution GEBCO Gridded Bathymetric Dataset was used for modeling, mapping and visualization. The study aimed to compare and analyse variations in the geomorphic structures of the two parts of the trench and to visualize variations in the geological, geophysical and bathymetric settings. Technically, the cartographic work was performed using scripting based on the Generic Mapping Toolset (GMT). Modelled cross-sectioning orthogonal profiles transecting the trench in a perpendicular direction were automatically digitized and graphed in the two segments. The results of the bathymetric analysis shown that the southern part is shallower: with deeper values in absolute (139 samples between –7000 to –8000 m) and statistical records (the most frequent values are within –5500 to –5800 m) comparing to the northern segment (–5300 to –5500 m). The geomorphological analysis shows a more complicated relief in the northern part of the trench, which has a higher seismic activity. The southern part has a gentler slope on the Honshu island side. The geoid modeling along the trench ranges in 0–20 mGal. The highest values are recorded by the Honshu Island (>40 mGal). The rest of the area has rather moderate undulations (20–40 mGal). The free-air marine gravity of the Sea of Japan is Numéro de notice : A2020-782 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3846/gac.2020.11524 date de publication en ligne : 08/10/2020 En ligne : https://doi.org/10.3846/gac.2020.11524 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96477 [article]

Can ensemble techniques improve coral reef habitat classification accuracy using multispectral data? / Mohammad Shawkat Hossain in Geocarto international, vol 35 n° 11 ([01/08/2020])  

Public [article]  inGeocarto international > vol 35 n° 11 [01/08/2020] . - pp 214 - 1232 Titre : Can ensemble techniques improve coral reef habitat classification accuracy using multispectral data? Type de document : Article/Communication Auteurs : Mohammad Shawkat Hossain, Auteur ; Aidy M. Muslim, Auteur ; Muhammad Izuan Nadzri, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 214 - 1232 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] biodiversité [Termes IGN] carte bathymétrique [Termes IGN] Chine, mer de [Termes IGN] classification barycentrique [Termes IGN] classification hypercube [Termes IGN] classification par maximum de vraisemblance [Termes IGN] distribution de Fisher [Termes IGN] fond marin [Termes IGN] image multibande [Termes IGN] Malaisie [Termes IGN] précision de la classification [Termes IGN] récif corallien [Termes IGN] réflectance spectrale Résumé : (auteur) Remote sensing has potential in studies of the benthic habitat and extracting the reflectance from the data of multispectral sensors, but traditional image classification techniques cannot provide coral habitat maps with adequate accuracy. This study tested five traditional and three ensemble classification techniques on QuickBird for mapping the benthic composition of coral reefs on the Lang Tengah Island (Malaysia). The common techniques, minimum distance, maximum likelihood, K-nearest neighbour, Fisher and parallelepiped techniques were compared with ensemble classifiers, such as majority voting (MV), simple averaging, and mode combination. The per-class accuracy of the habitat detection improved in the ensemble classifiers; in particular, the MV classifier achieved 95%, 65%, 75% and 95% accuracies for coral, sparse coral, coral rubble and sand, respectively. Ensembles increased the accuracy of the habitat mapping classification by 28%, relative to conventional techniques. Thus, the ensemble techniques can be preferred over the traditional for benthic habitat mapping. Numéro de notice : A2020-459 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2018.1557263 date de publication en ligne : 12/02/2019 En ligne : https://doi.org/10.1080/10106049.2018.1557263 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95566 [article]

The map is the story: the U-shaped line in western news media coverage of the geopolitics of the South China Sea / Peter Vujakovic in International journal of cartography, Vol 6 n° 2 (July 2020)  

Public [article]  inInternational journal of cartography > Vol 6 n° 2 (July 2020) . - pp 179 - 201 Titre : The map is the story: the U-shaped line in western news media coverage of the geopolitics of the South China Sea Type de document : Article/Communication Auteurs : Peter Vujakovic, Auteur Année de publication : 2020 Article en page(s) : pp 179 - 201 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie [Termes IGN] Chine [Termes IGN] Chine, mer de [Termes IGN] communication cartographique [Termes IGN] géopolitique [Termes IGN] histoire [Termes IGN] média [Termes IGN] presse (media) [Termes IGN] représentation cartographique Résumé : (auteur) China’s claim to a large part of the South China Sea (SCS) is indicated by a specific cartographic convention, the U-shaped (or dashed) line, shown on its official maps. The line has become an important element in Western popular discourse concerning the geopolitics of the SCS. This paper argues that the cartographic re-presentation of the U-shaped line in the Western press contributes to an ‘orientalist’ conception that portrays China as ‘other’; as aggressive and unwilling to ‘play by the rules’, and a portrayal of the whole region as potentially unstable. Its re-circulation may, however, work to China’s advantage by reinforcing cartographic precedent and creating a specific ‘geographic imagination’ of the SCS. Maps are regarded as an important element in the ‘spectacle of fear’ propagated by the West, with the representations of the SCS shown to be part of a wider use of maps by the press to cover issues related to geopolitics and conflict. Numéro de notice : A2020-442 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/23729333.2018.1541581 date de publication en ligne : 10/12/2018 En ligne : https://doi.org/10.1080/23729333.2018.1541581 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95500 [article]

Combining GF-2 and RapidEye satellite data for mapping mangrove species using ensemble machine-learning methods / Liheng Peng in International Journal of Remote Sensing IJRS, vol 41 n° 3 (15 - 22 janvier 2020)  

Public [article]  inInternational Journal of Remote Sensing IJRS > vol 41 n° 3 (15 - 22 janvier 2020) . - pp 813 - 838 Titre : Combining GF-2 and RapidEye satellite data for mapping mangrove species using ensemble machine-learning methods Type de document : Article/Communication Auteurs : Liheng Peng, Auteur ; Kai Liu, Auteur ; Jingjing Cao, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 813 - 838 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] apprentissage automatique [Termes IGN] boosting adapté [Termes IGN] Chine, mer de [Termes IGN] classification et arbre de régression [Termes IGN] classification par forêts aléatoires [Termes IGN] écosystème [Termes IGN] extraction de la végétation [Termes IGN] île [Termes IGN] image Gaofen [Termes IGN] image RapidEye [Termes IGN] image satellite [Termes IGN] mangrove [Termes IGN] modèle numérique de surface [Termes IGN] précision de la classification [Termes IGN] Rotation Forest classification Résumé : (auteur) Mangrove forests are important constitutions for sustainable development of coastal ecosystems, and they are often mapped and monitored with remote sensing approaches. Satellite images allow detailed studies of the distribution and composition of mangrove forests, and therefore facilitate the management and conservation of the ecosystems. The combination of multiple types of satellite images with different spatial and spectral resolutions is helpful in mangrove forests extraction and mangrove species discrimination as it reduces sampling workload and increases classification accuracies. In this study, the 1.0-m-resolution Gaofen-2 (GF-2) and the 5.0-m-resolution RapidEye-4 (RE-4) satellite images, acquired in February 2017 and November 2016 respectively, were used with ensemble machine-learning and object-oriented methods for mangroves mapping at both the community and species levels of the Qi’ao Island, Zhuhai, China. First, the mangroves on the island were segmented from the GF-2 image on a large scale, and then they were extracted combining with their digital elevation model (DEM) data. Second, the GF-2 image was further processed on a fine scale, in which object-oriented features from both the GF-2 and RE-4 images were extracted for each mangrove species. Third, it is followed by the mangrove species classification process which involves three ensemble machine-learning methods: the adaptive boosting (AdaBoost), the random forest (RF) and the rotation forest (RoF). These three methods employed a classification and regression tree (CART) as the base classifier. The results show that the overall accuracy (OA) of mangrove area extraction on the Qi’ao Island with the auxiliary data, DEM, achieves 98.76% (Kappa coefficient (κ) = 0.9289). The features extracted by the GF-2 and RE-4 images were shown to be beneficial for mangrove species discrimination. A maximum improvement in the OA of approximately 8% and a κκ of approximately 0.10 were achieved when employing RoF (OA = 92.01%, κ = 0.9016). Ensemble-learning methods can significantly improve the classification accuracy of CART, and the use of a bagging scheme (RF and RoF) is shown as a better way to map mangrove species than adaptive boosting (AdaBoost). In addition, RoF performed well in mangrove species classification but it was not as robust as the RF, whose average OA and κκ were 80.59% and 0.7608, respectively, while the RoF’s were 77.45% and 0.7214, respectively, in the 10-fold cross-validation. Numéro de notice : A2020-212 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/01431161.2019.1648907 date de publication en ligne : 30/07/2019 En ligne : https://doi.org/10.1080/01431161.2019.1648907 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94897 [article]

Applying iterative method to solving high-order terms of seafloor topography / Diao Fan in Marine geodesy, Vol 43 n° 1 (January 2020)  

Public [article]  inMarine geodesy > Vol 43 n° 1 (January 2020) . - pp 63 - 85 Titre : Applying iterative method to solving high-order terms of seafloor topography Type de document : Article/Communication Auteurs : Diao Fan, Auteur ; Shanshan Li, Auteur ; Shuyu Meng, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 63 - 85 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Topographie [Termes IGN] Chine, mer de [Termes IGN] fond marin [Termes IGN] force de gravitation [Termes IGN] gravimétrie en mer [Termes IGN] inversion [Termes IGN] itération [Termes IGN] relief sous-marin Résumé : (auteur) We introduce an iterative inversion method to address the problems in high-order seafloor topography inversion using gravity data (gravity anomaly and vertical gravity gradient anomaly), such as the difficulty in computing the equation and the uniqueness of the calculation results. A part of the South China Sea is selected as the experimental area. Considering the coherence and admittance function of gravity topography and vertical gravity gradient topography, the inversion band of the gravity anomaly and vertical gravity gradient anomaly in the study area is 30 km–120 km. Seafloor topography models of different orders are constructed using an iterative method, and the performance of each seafloor topography model is analyzed against ETOPO1 and other seafloor topography models. The experimental results show that as the inversion order increases, the clarity and richness of seafloor topographic expression continuously improve. However, the accuracy of seafloor topography inversion does not improve significantly when the inversion order exceeds a certain value, which is related to the contribution of high-order seafloor topography to gravity information. The results show that the accuracy of BGT4 (inversion model constructed by the gravity anomaly) is slightly poorer than that of BVGGT4 (inversion model constructed by the vertical gravity gradient anomaly) in areas with complex topography, such as multi-seamounts and trenches, and the results are generally better in areas with flat seafloor topography. Numéro de notice : A2020-463 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/01490419.2019.1670298 date de publication en ligne : 08/10/2019 En ligne : https://doi.org/10.1080/01490419.2019.1670298 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95125 [article]

New quantitative indices from 3D modeling by photogrammetry to monitor coral reef environments / Isabel Urbina-Barreto (2020)  

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Sea ice extent detection in the Bohai Sea using Sentinel-3 OLCI data / Hua Su in Remote sensing, Vol 11 n° 20 (October 2019)  

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Introducing a vertical land motion model for improving estimates of sea level rates derived from tide gauge records affected by earthquakes / Anna Klos in GPS solutions, vol 23 n° 4 (October 2019)  

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Sea level variation around Australia and its relation to climate indices / Armin Agha Karimi in Marine geodesy, vol 42 n° 5 (September 2019)  

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Vertical land motion in the Southwest and Central Pacific from available GNSS solutions and implications for relative sea levels / Valérie Ballu in Geophysical journal international, vol 218 n° 3 (September 2019)  

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Sea level prediction in the Yellow Sea from satellite altimetry with a combined least squares-neural network approach / Jian Zhao in Marine geodesy, vol 42 n° 4 (July 2019)  

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Reconciling upper mantle seismic velocity and density structure below ocean basins / Isabelle Panet (2019)

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Sea surface salinity remote sensing / Emmanuel P. Dinnat (2019)  

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Assessing the performance of multi-GNSS precise point positioning in Asia-Pacific region / X. Zhao in Survey review, vol 49 n° 354 (September 2017)  

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Marine terraces and rates of vertical tectonic motion: The importance of glacio-isostatic adjustment along the Pacific coast of central North America / Alexander R. Simms in GSA bulletin, vol 128 n° 1-2 ([01/01/2016])  

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