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Detecting abandoned farmland using harmonic analysis and machine learning / Heeyeun Yoon in ISPRS Journal of photogrammetry and remote sensing, vol 166 (August 2020)
[article]
Titre : Detecting abandoned farmland using harmonic analysis and machine learning Type de document : Article/Communication Auteurs : Heeyeun Yoon, Auteur ; Soyoun Kim, Auteur Année de publication : 2020 Article en page(s) : pp 201 - 212 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse harmonique
[Termes IGN] apprentissage automatique
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] Corée du sud
[Termes IGN] gestion des ressources
[Termes IGN] inventaire
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] Normalized Difference Water Index
[Termes IGN] phénologie
[Termes IGN] production agricole
[Termes IGN] Soil Adjusted Vegetation Index
[Termes IGN] surface cultivéeRésumé : (auteur) It is critical to inventory abandoned farmland soon after it is generated, to better manage agricultural resources and to prevent negative consequences that would otherwise follow. This study aims to distinguish abandoned farmlands from active croplands—rice paddy and agricultural fields—by discerning the phenological trajectories over a short-term period of three years (Jan. 2016 to Dec. 2018) in Gwanyang City in South Korea. For Support Vector Machine (SVM) classification, we fully utilized parameters derived from harmonic analyses of the three vegetation indices (VIs: NDVI, NDWI, and SAVI) extracted from Sentinel-2A imagery. The harmonic analyses proved that higher-order sinusoid components produced better fitting to explain the trajectory of the VIs—the maximum adjusted was 95.23%—and the multiple VIs diversified the attributes for the classifications. Consequently, the higher-order harmonic components and the additional VIs increased the accuracy when used in SVM classification. The best performing classification was achieved with a composite of harmonic terms derived from the three VIs, yielding overall accuracy of 90.72%, Kappa index of 0.858, and user’s accuracy for abandoned farmland of 93.40%. The proposed method here would greatly improve the process of detecting abandoned farmland, despite a relatively short observation period, and enable a rapid response to the occurrence of abandonment. Numéro de notice : A2020-356 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2020.05.021 Date de publication en ligne : 16/06/2020 En ligne : https://doi.org/10.1016/j.isprsjprs.2020.05.021 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95243
in ISPRS Journal of photogrammetry and remote sensing > vol 166 (August 2020) . - pp 201 - 212[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2020081 RAB Revue Centre de documentation En réserve L003 Disponible 081-2020083 DEP-RECP Revue LASTIG Dépôt en unité Exclu du prêt 081-2020082 DEP-RECF Revue Nancy Dépôt en unité Exclu du prêt Improved arctic ocean mass variability inferred from time-variable gravity with constraints and dual leakage correction / Dapeng Mu in Marine geodesy, Vol 43 n° 3 (May 2020)
[article]
Titre : Improved arctic ocean mass variability inferred from time-variable gravity with constraints and dual leakage correction Type de document : Article/Communication Auteurs : Dapeng Mu, Auteur ; Tianhe Xu, Auteur ; Guochang Xu, Auteur Année de publication : 2020 Article en page(s) : pp 269 - 284 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Arctique, océan
[Termes IGN] données GRACE
[Termes IGN] harmonique sphérique
[Termes IGN] marée océaniqueRésumé : (Auteur) The ocean mass variability inferred from Gravity Recovery and Climate Experiment (GRACE) satellites mission is challenged by the stripes and the leakage across land-ocean boundary. The recently released GRACE mascons solutions are advanced by applying constraints that remove efficiently the stripes and dual leakage correction that restores the coastal ocean mass variability. Here we quantitatively evaluate the improvement in the Arctic Ocean mass variability by GRACE mascons. To do so, we compare the combination of GRACE solutions (including the mascons solutions and traditional spherical harmonic coefficients (SHCs) solutions) and the steric estimates against the altimeter observations. Our results suggest that mascons solutions produce stronger correlations compared to SHCs solutions, especially along the coastal zone, indicating the importance of the dual leakage correction. Stronger correlation is produced by the mascons over a small basin in the interior of the Arctic Ocean, suggesting that mascons solutions deliver better ocean mass variability than the SHCs solutions. Since the comparisons are carried out over two sub-basins, we conclude that mascons are able to provide better regional ocean mass variability that may have implications for regional sea level budget, in particular over the coastal zone. Numéro de notice : A2020-185 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01490419.2020.1711832 Date de publication en ligne : 17/01/2020 En ligne : https://doi.org/10.1080/01490419.2020.1711832 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94975
in Marine geodesy > Vol 43 n° 3 (May 2020) . - pp 269 - 284[article]A line integral approach for the computation of the potential harmonic coefficients of a constant density polyhedron / Olivier Jamet in Journal of geodesy, Vol 94 n°3 (March 2020)
[article]
Titre : A line integral approach for the computation of the potential harmonic coefficients of a constant density polyhedron Type de document : Article/Communication Auteurs : Olivier Jamet , Auteur ; Dimitrios Tsoulis, Auteur Année de publication : 2020 Projets : Université de Paris / Clerici, Christine Article en page(s) : n° 30 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse harmonique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] harmonique sphérique
[Termes IGN] implémentation (informatique)
[Termes IGN] polyèdre
[Termes IGN] potentiel de pesanteur terrestreRésumé : (auteur) A novel approach for the computation of the spherical harmonic coefficients of the gravity field of a constant density polyhedron is presented. The proposed method is based on the expression of these coefficients as the volume integral of solid harmonics. It is well known that the divergence theorem leads to an expression of these volume integrals as surface integrals. We show that these surface integrals can be expressed as the sum of line integrals along the edges of the polyhedron. In contrast to previous approaches, the values of the spherical harmonic coefficients at a given degree and order result directly from the computation of the line integrals. The performed numerical implementation revealed the stability of the proposed algorithm up to degree 360 for a prismatic test source. Numéro de notice : A2020-154 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01358-8 Date de publication en ligne : 17/02/2020 En ligne : https://doi.org/10.1007/s00190-020-01358-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94803
in Journal of geodesy > Vol 94 n°3 (March 2020) . - n° 30[article]Research on empirical correction models of GPS Block IIF and BDS satellite inter-frequency clock bias / Xiaopeng Gong in Journal of geodesy, Vol 94 n°3 (March 2020)
[article]
Titre : Research on empirical correction models of GPS Block IIF and BDS satellite inter-frequency clock bias Type de document : Article/Communication Auteurs : Xiaopeng Gong, Auteur ; Shengfeng Gu, Auteur ; Yidong Lou, Auteur ; et al., Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse harmonique
[Termes IGN] décalage d'horloge
[Termes IGN] données BeiDou
[Termes IGN] données GPS
[Termes IGN] erreur systématique interfréquence d'horloge
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïté
[Termes IGN] triple différenceRésumé : (auteur) Triple-frequency observations will introduce an inter-frequency clock bias (IFCB) between the new frequency and the original dual-frequency observations. It has been verified that satellite IFCB can reach dozens of centimeters and several centimeters for GPS Block IIF satellite and BDS satellite, respectively. The existence of satellite IFCB will significantly affect undifferenced triple-frequency data processing. Based on 4-year data collected from 80 globally distributed stations, the long-term characteristics of IFCB coefficients obtained by using harmonic analysis have been studied. The results demonstrate that the coefficients of IFCB periodic model cannot be well fitted only by using sun elevation angle. Also, coefficients have obvious periodic characteristics and their periods differ among different satellites. Thus, a new linear-plus-periodic model is proposed to fit the long-term coefficients. Then, IFCB empirical correction models for 12 GPS Block IIF satellites and BDS GEO and IGSO satellites are built. In order to validate the correction model, IFCB standard deviation (STD), triple-frequency precise point positioning (PPP) and undifferenced extra-wide-lane (EWL) ambiguity resolution are employed. The results based on more than 4-year observations show that, with correction model applied, the average IFCB STD decreases by about 65.5% and 45.5% for GPS and BDS satellites, respectively. Compared to triple-frequency PPP without IFCB correction, triple-frequency PPP results with IFCB correction show that Up, North and East components accuracy are improved by 12.3%, 16.0% and 13.2%, respectively. Besides, IFCB correction will greatly improve the consistence of EWL fractional cycle bias among different stations and improve the success rate of EWL ambiguity resolution. Numéro de notice : A2020-157 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01365-9 Date de publication en ligne : 06/03/2020 En ligne : https://doi.org/10.1007/s00190-020-01365-9 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94808
in Journal of geodesy > Vol 94 n°3 (March 2020)[article]ITRF2014, Earth figure changes, and geocenter velocity: Implications for GIA and recent ice melting / Laurent Métivier in Journal of geophysical research : Solid Earth, vol 125 n° 2 (February 2020)
[article]
Titre : ITRF2014, Earth figure changes, and geocenter velocity: Implications for GIA and recent ice melting Type de document : Article/Communication Auteurs : Laurent Métivier , Auteur ; Hélène Rouby , Auteur ; Paul Rebischung , Auteur ; Zuheir Altamimi , Auteur Année de publication : 2020 Projets : 2-Pas d'info accessible - article non ouvert / Clerici, Christine Article en page(s) : n° e2019JB018333 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] figure de la Terre
[Termes IGN] fonte des glaces
[Termes IGN] harmonique sphérique
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] manteau terrestre
[Termes IGN] mouvement du géocentre
[Termes IGN] rebond post-glaciaire
[Termes IGN] vitesse de déplacementRésumé : (auteur) Using a selection of Global Navigation Satellite System vertical velocities from the latest solution of the International Terrestrial Reference Frame (ITRF) ITRF2014, we calculate the degree-1 and degree-2 spherical harmonics coefficients (SHC) of the solid Earth figure changes at different dates, with realistic errors that take into account the inhomogeneity of the network. We find that the SHC are globally close to zero except the zonal coefficients, which show values notably larger than those derived from different glacial isostatic adjustment (GIA) models and which have tended to increase during the time span of observations. We show that these differences are most probably due to global recent ice melting (RIM). Assuming elastic RIM deformation, we then investigate the Earth's geocenter velocity and the geoid oblateness time evolution (J2-rate) derived from our SHC estimations. The obtained geocenter velocity reaches 0.9 ± 0.5 mm/year in 2013 with a z-component of 0.8 ± 0.4 mm/year, which is slightly larger than previous estimations. We compare our J2-rate estimations with observations. Our estimations show a similar acceleration in J2 after 2000. However, our estimates are notably larger than the observations. This indicates either that the J2-rate due to GIA processes is lower than expected (as proposed by Nakada et al., 2015, 2016) or that the deformation induced by RIM is not purely elastic, or both. Finally, we show that viscous relaxation or phase transitions in the mantle transition zone may only partly explain this discrepancy. This raises the question of the accuracy of current mass estimations of RIM and GIA models. Numéro de notice : A2020-363 Affiliation des auteurs : UMR IPGP-Géod (2020- ) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/2019JB018333 Date de publication en ligne : 02/01/2020 En ligne : https://doi.org/10.1029/2019JB018333 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98263
in Journal of geophysical research : Solid Earth > vol 125 n° 2 (February 2020) . - n° e2019JB018333[article]PermalinkPermalinkNonparametric Bayesian learning for collaborative robot multimodal introspection / Xuefeng Zhou (2020)PermalinkPermalinkData-adaptive spatio-temporal filtering of GRACE data / Paoline Prevost in Geophysical journal international, vol 219 n° 3 (December 2019)PermalinkA global vertical datum defined by the conventional geoid potential and the Earth ellipsoid parameters / Hadi Amin in Journal of geodesy, vol 93 n°10 (October 2019)PermalinkMass variation observing system by high low inter-satellite links (MOBILE) : a new concept for sustained observation of mass transport from space / Roland Pail in Journal of geodetic science, vol 9 n° 1 (January 2019)PermalinkVertical and horizontal spheroidal boundary-value problems / Michal Šprlák in Journal of geodesy, vol 92 n° 7 (July 2018)PermalinkToward a global horizontal and vertical elastic load deformation model derived from GRACE and GNSS station position time series / Kristel Chanard in Journal of geophysical research : Solid Earth, vol 123 n° 4 (April 2018)PermalinkTransformation between surface spherical harmonic expansion of arbitrary high degree and order and double Fourier series on sphere / Toshio Fukushima in Journal of geodesy, vol 92 n° 2 (February 2018)PermalinkExtension of satellite altimetry Jason-2 sea level anomalies towards the Red Sea coast using polynomial harmonic techniques / A. M. Taqi in Marine geodesy, vol 40 n° 5 (September 2017)PermalinkExtracting urban functional regions from points of interest and human activities on location-based social networks / Song Gao in Transactions in GIS, vol 21 n° 3 (June 2017)PermalinkComputationally efficient hyperspectral data learning based on the doubly stochastic dirichlet process / Xing Sun in IEEE Transactions on geoscience and remote sensing, vol 55 n° 1 (January 2017)PermalinkDiscriminative-dictionary-learning-based multilevel point-cluster features for ALS point-cloud classification / Zhenxin Zhang in IEEE Transactions on geoscience and remote sensing, vol 54 n° 12 (December 2016)PermalinkOn the spectral combination of satellite gravity model, terrestrial and airborne gravity data for local gravimetric geoid computation / Tao Jian in Journal of geodesy, vol 90 n° 12 (December 2016)PermalinkDirichlet process based active learning and discovery of unknown classes for hyperspectral image classification / Hao Wu in IEEE Transactions on geoscience and remote sensing, vol 54 n° 8 (August 2016)PermalinkPermalinkContribution of mass density heterogeneities to the quasigeoid-to-geoid separation / Robert Tenzer in Journal of geodesy, vol 90 n° 1 (January 2016)PermalinkTraitement du signal marégraphique par analyse harmonique pour la détermination d'une référence altimétrique pour l'Algérie / A. Rami in Bulletin des sciences géographiques, n° 30 (2015 - 2016)PermalinkA moving weighted harmonic analysis method for reconstructing high-quality SPOT VEGETATION NDVI time-series data / Gang Yang in IEEE Transactions on geoscience and remote sensing, vol 53 n° 11 (November 2015)Permalink