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Change detection in forests and savannas using statistical analysis based on geographical objects / Lucilia Rezende Leite in Boletim de Ciências Geodésicas, vol 23 n° 2 (abr - jun 2017)
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Titre : Change detection in forests and savannas using statistical analysis based on geographical objects Type de document : Article/Communication Auteurs : Lucilia Rezende Leite, Auteur ; Luis Marcelo Tavares de Carvalho, Auteur ; Fortunato Menezes da Silva, Auteur Année de publication : 2017 Article en page(s) : pp 284 - 295 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse d'image orientée objet
[Termes IGN] analyse diachronique
[Termes IGN] Brésil
[Termes IGN] classification par la distance de Mahalanobis
[Termes IGN] détection de changement
[Termes IGN] forêt équatoriale
[Termes IGN] image Landsat-TM
[Termes IGN] khi carré
[Termes IGN] réflectance végétale
[Termes IGN] savane
[Termes IGN] segmentation d'imageRésumé : (auteur) The aim of this work was to assess techniques of land cover change detection in areas of Brazilian Forest and Savanna, using Landsat 5/TM images, and two iterative statistical methodologies based on geographical objects. The sensitivity of the methodologies was assessed in relation to the heterogeneity of the input data, the use of reflectance data and vegetation indices, and the use of different levels of confidence. The periods analyzed were from 2000 to 2006, and from 2006 to 2010. After the segmentation of images, the descriptive statistics average and standard deviation of each object were extracted. The determination of change objects was realized in an iterative way based on the Mahalanobis Distance and the chi-square distribution. The results were validated with an early visual detection and analyzed according to Receiver Operating Characteristic (ROC) Curve. Significant gains were obtained by using vegetation masks and bands 3 and 4 for both areas tested with 94,67% and 95,02% of the objects correctly detected as changes, respectively for the areas of Forest and Savanna. The use of the NDVI and different images were not satisfactory in this study. Numéro de notice : A2017-394 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1590/S1982-21702017000200018 En ligne : http://dx.doi.org/10.1590/S1982-21702017000200018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85910
in Boletim de Ciências Geodésicas > vol 23 n° 2 (abr - jun 2017) . - pp 284 - 295[article]Decomposition of LiDAR waveforms by B-spline-based modeling / Xiang Shen in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)
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Titre : Decomposition of LiDAR waveforms by B-spline-based modeling Type de document : Article/Communication Auteurs : Xiang Shen, Auteur ; Qing-Quan Li, Auteur ; Guofeng Wu, Auteur ; Jiasong Zhu, Auteur Année de publication : 2017 Article en page(s) : pp 182 - 191 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] B-Spline
[Termes IGN] décomposition de Gauss
[Termes IGN] distribution, loi de
[Termes IGN] forme d'onde pleine
[Termes IGN] traitement du signal
[Termes IGN] transformation géométrique
[Termes IGN] translationRésumé : (Auteur) Waveform decomposition is a widely used technique for extracting echoes from full-waveform LiDAR data. Most previous studies recommended the Gaussian decomposition approach, which employs the Gaussian function in laser pulse modeling. As the Gaussian-shape assumption is not always satisfied for real LiDAR waveforms, some other probability distributions (e.g., the lognormal distribution, the generalized normal distribution, and the Burr distribution) have also been introduced by researchers to fit sharply-peaked and/or heavy-tailed pulses. However, these models cannot be universally used, because they are only suitable for processing the LiDAR waveforms in particular shapes. In this paper, we present a new waveform decomposition algorithm based on the B-spline modeling technique. LiDAR waveforms are not assumed to have a priori shapes but rather are modeled by B-splines, and the shape of a received waveform is treated as the mixture of finite transmitted pulses after translation and scaling transformation. The performance of the new model was tested using two full-waveform data sets acquired by a Riegl LMS-Q680i laser scanner and an Optech Aquarius laser bathymeter, comparing with three classical waveform decomposition approaches: the Gaussian, generalized normal, and lognormal distribution-based models. The experimental results show that the B-spline model performed the best in terms of waveform fitting accuracy, while the generalized normal model yielded the worst performance in the two test data sets. Riegl waveforms have nearly Gaussian pulse shapes and were well fitted by the Gaussian mixture model, while the B-spline-based modeling algorithm produced a slightly better result by further reducing 6.4% of fitting residuals, largely benefiting from alleviating the adverse impact of the ringing effect. The pulse shapes of Optech waveforms, on the other hand, are noticeably right-skewed. The Gaussian modeling results deviated significantly from original signals, and the extracted echo parameters were clearly inaccurate and unreliable. The B-spline-based method performed significantly better than the Gaussian and lognormal models by reducing 45.5% and 11.5% of their fitting errors, respectively. Much more precise echo properties can accordingly be retrieved with a high probability. Benefiting from the flexibility of B-splines on fitting arbitrary curves, the new method has the potentiality for accurately modeling various full-waveform LiDAR data, whether they are nearly Gaussian or non-Gaussian in shape. Numéro de notice : A2017-334 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2017.03.006 En ligne : https://doi.org/10.1016/j.isprsjprs.2017.03.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85487
in ISPRS Journal of photogrammetry and remote sensing > vol 128 (June 2017) . - pp 182 - 191[article]Exemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2017061 RAB Revue Centre de documentation En réserve L003 Disponible 081-2017063 DEP-EXM Revue LASTIG Dépôt en unité Exclu du prêt 081-2017062 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt Displacement monitoring and modelling of a high-speed railway bridge using C-band Sentinel-1 data / Qihuan Huang in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)
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Titre : Displacement monitoring and modelling of a high-speed railway bridge using C-band Sentinel-1 data Type de document : Article/Communication Auteurs : Qihuan Huang, Auteur ; Michele Crosetto, Auteur ; Oriol Monserrat, Auteur ; Bruno Crippa, Auteur Année de publication : 2017 Article en page(s) : pp 204 - 211 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bande C
[Termes IGN] coin réflecteur
[Termes IGN] image Sentinel-SAR
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] pont
[Termes IGN] surveillance d'ouvrage
[Termes IGN] température de l'airRésumé : (Auteur) Bridge displacement monitoring is one of the key components of bridge structural health monitoring. Traditional methods, usually based on limited sets of sensors mounted on a given bridge, collect point-like deformation information and have the disadvantage of providing incomplete displacement information. In this paper, a Persistent Scatterer Interferometry (PSI) approach is used to monitor the displacements of the Nanjing Dashengguan Yangtze River high-speed railway bridge. Twenty-nine (29) European Space Agency Sentinel-1A images, acquired from April 25, 2015 to August 5, 2016, were used in the PSI analysis. A total of 1828 measurement points were selected on the bridge. The results show a maximum longitudinal displacement of about 150 mm on each side of the bridge. The measured displacements showed a strong correlation with the environmental temperature at the time the images used were acquired, indicating that they were due to thermal expansion of the bridge. At each pier, a regression model based on the PSI-measured displacements was compared with a model based on in-situ measurements. The good agreement of these models demonstrates the capability of the PSI technique to monitor long-span railway bridge displacements. By comparing the modelled displacements and dozens of PSI measurements, we show how the performance of movable bearings can be evaluated. The high density of the PSI measurement points is advantageous for the health monitoring of the entire bridge Numéro de notice : A2017-335 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2017.03.016 En ligne : https://doi.org/10.1016/j.isprsjprs.2017.03.016 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85492
in ISPRS Journal of photogrammetry and remote sensing > vol 128 (June 2017) . - pp 204 - 211[article]Exemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2017061 RAB Revue Centre de documentation En réserve L003 Disponible 081-2017063 DEP-EXM Revue LASTIG Dépôt en unité Exclu du prêt 081-2017062 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt Evaluation of forest fire on Madeira Island using Sentinel-2A MSI imagery / Gabriel Navarro in International journal of applied Earth observation and geoinformation, vol 58 (June 2017)
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Titre : Evaluation of forest fire on Madeira Island using Sentinel-2A MSI imagery Type de document : Article/Communication Auteurs : Gabriel Navarro, Auteur ; Isabel Caballero, Auteur ; Gustavo Silva, Auteur ; Pedro-Cecilio Parra, Auteur ; Águeda Vázquez, Auteur ; Rui Caldeira, Auteur Année de publication : 2017 Article en page(s) : pp 97 - 106 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] correction atmosphérique
[Termes IGN] image Sentinel-MSI
[Termes IGN] incendie de forêt
[Termes IGN] indice de végétation
[Termes IGN] Madère, île de
[Termes IGN] signature spectrale
[Termes IGN] surveillance de la végétationRésumé : (auteur) A forest fire started on August 8th, 2016 in several places on Madeira Island causing damage and casualties. As of August 10th the local media had reported the death of three people, over 200 people injured, over 950 habitants evacuated, and 50 houses damaged. This study presents the preliminary results of the assessment of several spectral indices to evaluate the burn severity of Madeira fires during August 2016. These spectral indices were calculated using the new European satellite Sentinel-2A launched in June 2015. The study confirmed the advantages of several spectral indices such as Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Normalized Burn Ratio (NBR) and Normalized Difference Vegetation Index (NDVIreXn) using red-edge spectral bands to assess the post-fire conditions. Results showed high correlation between NDVI, GNDVI, NBR and NDVIre1n spectral indices and the analysis performed by Copernicus Emergency Management Service (EMSR175), considered as the reference truth. Regarding the red-edge spectral indices, the NDVIre1n (using band B5, 705 nm) presented better results compared with B6 (740 nm) and B7 (783 nm) bands. These preliminary results allow us to assume that Sentinel-2 will be a valuable tool for post-fire monitoring. In the future, the two twin Sentinel-2 satellites will offer global coverage of the Madeira Archipelago every five days, therefore allowing the simultaneous study of the evolution of the burnt area and reforestation information with high spatial (up to 10 m) and temporal resolution (5 days). Numéro de notice : A2017-366 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.jag.2017.02.003 En ligne : https://doi.org/10.1016/j.jag.2017.02.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85794
in International journal of applied Earth observation and geoinformation > vol 58 (June 2017) . - pp 97 - 106[article]Integrated precipitable water from GPS observations and cimel sunphotometer measurements at CGO Belsk / Michal Kruczyk in Reports on geodesy and geoinformatics, vol 103 n° 1 (June 2017)
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Titre : Integrated precipitable water from GPS observations and cimel sunphotometer measurements at CGO Belsk Type de document : Article/Communication Auteurs : Michal Kruczyk, Auteur ; Tomasz Liwosz, Auteur ; Aleksander Pietruczuk, Auteur Année de publication : 2017 Article en page(s) : pp 46 - 65 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] données météorologiques
[Termes IGN] erreur systématique
[Termes IGN] photomètre
[Termes IGN] Pologne
[Termes IGN] réseau permanent EUREF
[Termes IGN] retard troposphérique
[Termes IGN] teneur intégrée en vapeur d'eauRésumé : (auteur) This paper describes results of integrated precipitable water co-located measurements from two techniques: GPS solution and CIMEL-318 sunphotometer. Integrated Precipitable Water (IPW) is an important meteorological parameter and is derived from GPS tropospheric solutions for GPS station at Central Geophysical Observatory (CGO), Polish Academy of Sciences (PAS), Belsk and compared with sunphotometer (CIMEL-318 device by Cimel Electronique) data provided by Aerosol Robotic Network (AERONET). Two dedicated and independent GPS solutions: network solution in the sub-network of European Permanent Network (EPN) and precise point positioning solution have been made to obtain tropospheric delays. The quality of dedicated tropospheric solutions has been verified by comparison with EPN tropospheric combined product. Several IPW comparisons and analyses revealed systematic difference between techniques (difference RMS is over 1 mm). IPW bias changes with season: annual close to 1 mm IPW (and semi-annual term also present). IPW bias is a function of atmospheric temperature. Probable cause of this systematic deficiency in solar photometry as IPW retrieval technique is a change of optical filter characteristics in CIMEL. Numéro de notice : A2017-574 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/rgg-2017-0005 En ligne : https://doi.org/10.1515/rgg-2017-0005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86699
in Reports on geodesy and geoinformatics > vol 103 n° 1 (June 2017) . - pp 46 - 65[article]Monitoring mangrove biomass change in Vietnam using SPOT images and an object-based approach combined with machine learning algorithms / Lien T.H. Pham in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)
PermalinkPushing the sensitivity limits of RTS-based continuous deformation monitoring of an alpine valley / Mariusz Frukacz in Applied geomatics, vol 9 n° 2 (June 2017)
PermalinkA time-series approach to estimating soil moisture from vegetated surfaces using L-band radar backscatter / Jeffrey D. Ouellette in IEEE Transactions on geoscience and remote sensing, vol 55 n° 6 (June 2017)
PermalinkTotal canopy transmittance estimated from small-footprint, full-waveform airborne LiDAR / Milutin Milenković in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)
PermalinkSemiautomatic detection and classification of materials in historic buildings with low-cost photogrammetric equipment / Javier Sanchez in Journal of Cultural Heritage, vol 25 (May - June 2017)
PermalinkAn unsupervised two-stage clustering approach for forest structure classification based on X-band InSAR data — A case study in complex temperate forest stands / Sahra Abdullahi in International journal of applied Earth observation and geoinformation, vol 57 (May 2017)
PermalinkCartographic continuum rendering based on color and texture interpolation to enhance photo-realism perception / Charlotte Hoarau in ISPRS Journal of photogrammetry and remote sensing, vol 127 (May 2017)
PermalinkComplétion d'image exploitant des données multispectrales / Frédéric Bousefsaf in Revue Française de Photogrammétrie et de Télédétection, n° 215 (mai - août 2017)
PermalinkCorrection du flou de mouvement sur des images prises de nuit depuis un véhicule de numérisation terrestre / Vincent Daval in Revue Française de Photogrammétrie et de Télédétection, n° 215 (mai - août 2017)
PermalinkEvaluation of multisource data for glacier terrain mapping : a neural net approach / Aparna Shukla in Geocarto international, vol 32 n° 5 (May 2017)
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