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Validation of canopy height profile methodology for small-footprint full-waveform airborne LiDAR data in a discontinuous canopy environment / Karolina D. Fieber in ISPRS Journal of photogrammetry and remote sensing, vol 104 (June 2015)
[article]
Titre : Validation of canopy height profile methodology for small-footprint full-waveform airborne LiDAR data in a discontinuous canopy environment Type de document : Article/Communication Auteurs : Karolina D. Fieber, Auteur ; Ian J. Davenport, Auteur ; Mihai A. Tanase, Auteur ; James M. Ferryman, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 144 - 157 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Australie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] forme d'onde pleine
[Termes IGN] hauteur des arbres
[Termes IGN] Leaf Area Index
[Termes IGN] modèle numérique de surface de la canopéeRésumé : (auteur) A Canopy Height Profile (CHP) procedure presented in Harding et al. (2001) for large footprint LiDAR data was tested in a closed canopy environment as a way of extracting vertical foliage profiles from LiDAR raw-waveform. In this study, an adaptation of this method to small-footprint data has been shown, tested and validated in an Australian sparse canopy forest at plot- and site-level. Further, the methodology itself has been enhanced by implementing a dataset-adjusted reflectance ratio calculation according to Armston et al. (2013) in the processing chain, and tested against a fixed ratio of 0.5 estimated for the laser wavelength of 1550 nm. As a by-product of the methodology, effective leaf area index (LAIe) estimates were derived and compared to hemispherical photography values. To assess the influence of LiDAR aggregation area size on the estimates in a sparse canopy environment, LiDAR CHPs and LAIes were generated by aggregating waveforms to plot- and site-level footprints (plot/site-aggregated) as well as in 5 m grids (grid-processed). LiDAR profiles were then compared to field biomass profiles generated based on field tree measurements. The correlation between field and LiDAR profiles was very high, with a mean R2 of 0.75 at plot-level and 0.86 at site-level for 55 plots and the corresponding 11 sites. Gridding had almost no impact on the correlation between LiDAR and field profiles (only marginally improvement), nor did the dataset-adjusted reflectance ratio. However, gridding and the dataset-adjusted reflectance ratio were found to improve the correlation between raw-waveform LiDAR and hemispherical photography LAIe estimates, yielding the highest correlations of 0.61 at plot-level and of 0.83 at site-level. This proved the validity of the approach and superiority of dataset-adjusted reflectance ratio of Armston et al. (2013) over a fixed ratio of 0.5 for LAIe estimation, as well as showed the adequacy of small-footprint LiDAR data for LAIe estimation in discontinuous canopy forests. Numéro de notice : A2015-702 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2015.03.001 En ligne : https://doi.org/10.1016/j.isprsjprs.2015.03.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78338
in ISPRS Journal of photogrammetry and remote sensing > vol 104 (June 2015) . - pp 144 - 157[article]Non-invasive forest litter characterization using full-wave inversion of microwave radar data / Frédéric André in IEEE Transactions on geoscience and remote sensing, vol 53 n° 2 (February 2015)
[article]
Titre : Non-invasive forest litter characterization using full-wave inversion of microwave radar data Type de document : Article/Communication Auteurs : Frédéric André, Auteur ; Mathieu Jonard, Auteur ; Sébastien Lambot, Auteur Année de publication : 2015 Article en page(s) : pp 828 - 840 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] caractérisation
[Termes IGN] déchet organique
[Termes IGN] Fagus (genre)
[Termes IGN] forêt
[Termes IGN] forme d'onde pleine
[Termes IGN] humidité du sol
[Termes IGN] image radar
[Termes IGN] litière
[Termes IGN] radar pénétrant GPR
[Termes IGN] rétrodiffusion
[Termes IGN] sol forestier
[Termes IGN] télédétection en hyperfréquenceRésumé : (Auteur) Litter is acknowledged to affect microwave remote sensing data over forests, and accurate quantification of litter radiative properties is essential for proper retrieval of forest soil water content and forest canopy biophysical characteristics from satellite or airborne sensors. Furthermore, detailed characterization of forest soil organic horizons is of paramount importance for ecological studies and for carbon cycle and global changerelated studies. Ultrawideband ground-penetrating radar (GPR) data acquired above beech forest litter were used to analyze the effects of litter on the backscattering and investigate the ability of GPR to quantitatively characterize the properties of the forest floor. Radar measurements were performed over different litter configurations (i.e., single layers of recently fallen litter (OL) or of fragmented litter (OF), and combined OL-OF layers) and thicknesses. Radar data were processed through full-wave inversion. Over the considered frequency range (0.8-4.0 GHz), attenuation of the radar signal increased as both frequency and litter thickness increase, due to scattering and dielectric losses. These effects were accounted for in the radar model through frequency dependence of litter apparent electrical conductivity. Good agreement (RMSE = 9.5 × 10-3 m) was observed between estimated and measured litter thicknesses. Radar data inversions provided reliable estimates of litter electromagnetic properties, with relative dielectric permittivity values around 1.2 and 3.9 for OL and OF litters, respectively, and corresponding values of 0.032 and 0.080 Sm-1 for litter apparent electrical conductivity at 4.0 GHz. These results show great promise for the use of GPR for noninvasive characterization of forest litter. Numéro de notice : A2015-102 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2014.2328776 En ligne : https://doi.org/10.1109/TGRS.2014.2328776 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75620
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 2 (February 2015) . - pp 828 - 840[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2015021 RAB Revue Centre de documentation En réserve L003 Disponible Compression strategies for LiDAR waveform cube / Grzegorz Jóźków in ISPRS Journal of photogrammetry and remote sensing, vol 99 (January 2015)
[article]
Titre : Compression strategies for LiDAR waveform cube Type de document : Article/Communication Auteurs : Grzegorz Jóźków, Auteur ; Charles K. Toth, Auteur ; Mihaela Quirk, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 1 - 13 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] compression de données
[Termes IGN] données lidar
[Termes IGN] forme d'onde pleineRésumé : (Auteur) Full-waveform LiDAR data (FWD) provide a wealth of information about the shape and materials of the surveyed areas. Unlike discrete data that retains only a few strong returns, FWD generally keeps the whole signal, at all times, regardless of the signal intensity. Hence, FWD will have an increasingly well-deserved role in mapping and beyond, in the much desired classification in the raw data format. Full-waveform systems currently perform only the recording of the waveform data at the acquisition stage; the return extraction is mostly deferred to post-processing. Although the full waveform preserves most of the details of the real data, it presents a serious practical challenge for a wide use: much larger datasets compared to those from the classical discrete return systems. Atop the need for more storage space, the acquisition speed of the FWD may also limit the pulse rate on most systems that cannot store data fast enough, and thus, reduces the perceived system performance. This work introduces a waveform cube model to compress waveforms in selected subsets of the cube, aimed at achieving decreased storage while maintaining the maximum pulse rate of FWD systems. In our experiments, the waveform cube is compressed using classical methods for 2D imagery that are further tested to assess the feasibility of the proposed solution. The spatial distribution of airborne waveform data is irregular; however, the manner of the FWD acquisition allows the organization of the waveforms in a regular 3D structure similar to familiar multi-component imagery, as those of hyper-spectral cubes or 3D volumetric tomography scans. This study presents the performance analysis of several lossy compression methods applied to the LiDAR waveform cube, including JPEG-1, JPEG-2000, and PCA-based techniques. Wide ranges of tests performed on real airborne datasets have demonstrated the benefits of the JPEG-2000 Standard where high compression rates incur fairly small data degradation. In addition, the JPEG-2000 Standard-compliant compression implementation can be fast and, thus, used in real-time systems, as compressed data sequences can be formed progressively during the waveform data collection. We conclude from our experiments that 2D image compression strategies are feasible and efficient approaches, thus they might be applied during the acquisition of the FWD sensors. Numéro de notice : A2014-633 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2014.10.003 En ligne : https://doi.org/10.1016/j.isprsjprs.2014.10.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75059
in ISPRS Journal of photogrammetry and remote sensing > vol 99 (January 2015) . - pp 1 - 13[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2015011 RAB Revue Centre de documentation En réserve L003 Disponible Empirical waveform decomposition and radiometric calibration of a terrestrial full-waveform laser scanner / Preston J. Hartzell in IEEE Transactions on geoscience and remote sensing, vol 53 n° 1 (January 2015)
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Titre : Empirical waveform decomposition and radiometric calibration of a terrestrial full-waveform laser scanner Type de document : Article/Communication Auteurs : Preston J. Hartzell, Auteur ; Craig L. Glennie, Auteur ; David C. Finnegan, Auteur Année de publication : 2015 Article en page(s) : pp 162 - 172 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] décomposition
[Termes IGN] données lidar
[Termes IGN] étalonnage de capteur (imagerie)
[Termes IGN] étalonnage radiométrique
[Termes IGN] forme d'onde pleine
[Termes IGN] instrumentation Riegl
[Termes IGN] Lidar
[Termes IGN] méthode des moindres carrés
[Termes IGN] modèle empirique
[Termes IGN] onde lidar
[Termes IGN] télémètre laser terrestreRésumé : (Auteur) The parametric models used in Light Detection And Ranging (LiDAR) waveform decomposition routines are inherently estimates of the sensor's system response to backscattered laser pulse power. This estimation can be improved with an empirical system response model, yielding reduced waveform decomposition residuals and more precise echo ranging. We develop an empirical system response model for a Riegl VZ-400 terrestrial laser scanner, from a series of observations to calibrated reflectance targets, and present a numerical least squares method for decomposing waveforms with the model. The target observations are also used to create an empirical radiometric calibration model that accommodates a nonlinear relationship between received optical power and echo peak amplitude, and to examine the temporal stability of the instrument. We find that the least squares waveform decomposition based on the empirical system response model decreases decomposition fitting errors by an order of magnitude for high-amplitude returns and reduces range estimation errors on planar surfaces by 17% over a Gaussian model. The empirical radiometric calibration produces reflectance values self-consistent to within 5% for several materials observed at multiple ranges, and analysis of multiple calibration data sets collected over a one-year period indicates that echo peak amplitude values are stable to within ±3% for target ranges up to 125 m. Numéro de notice : A2015-040 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2014.2320134 En ligne : https://doi.org/10.1109/TGRS.2014.2320134 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75122
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 1 (January 2015) . - pp 162 - 172[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2015011 RAB Revue Centre de documentation En réserve L003 Disponible Full-wave calibration of time- and frequency-domain ground-penetrating radar in far-field conditions / Mohammad Reza Mahmoudzadeh Ardekani in IEEE Transactions on geoscience and remote sensing, vol 52 n° 1 tome 2 (January 2014)
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Titre : Full-wave calibration of time- and frequency-domain ground-penetrating radar in far-field conditions Type de document : Article/Communication Auteurs : Mohammad Reza Mahmoudzadeh Ardekani, Auteur ; Sébastien Lambot, Auteur Année de publication : 2014 Article en page(s) : pp 664 - 678 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] étalonnage d'instrument
[Termes IGN] forme d'onde pleine
[Termes IGN] fréquence
[Termes IGN] image radar
[Termes IGN] radar pénétrant GPR
[Termes IGN] tempsRésumé : (Auteur) Full-wave modeling of ground-penetrating radar (GPR) data using Green's functions for wave propagation in planar layered media and antenna characteristic global reflection and transmission functions for describing far-field antenna effects, including antenna-medium interactions, has shown a great potential for nondestructive characterization of soils and materials. The accuracy of the retrieved parameters in the GPR data inversion depends on the accuracy of the GPR external calibration. In this research, we studied the stability and the repeatability of two different GPR systems, namely, frequency- and time-domain systems. A combination of a vector network analyzer and 800-5200 MHz horn antenna was used as a frequency-domain GPR (FD-GPR) whereas a GSSI GPR system using a 900 MHz bowtie antenna was used as a time-domain GPR (TD-GPR). Both GPR systems including their antennas were calibrated several times using measurements with the antennas at different heights over a perfect electric conductor (PEC) in the laboratory as well as over a water layer. In addition, measurements were performed over a thin water layer and a relatively thick sandy soil layer as validating medium. The results showed that the FD-GPR is relatively stable while the TD-GPR presents a significant drift which can be accounted for using corrections based on the air direct-coupling waves (free-space measurements). Water- and PEC-based calibrations provided very similar results for the GPR calibration functions. Inversions for the water layer and the sandy soil layer provided reliable results and showed a high degree of the repeatability for both radar systems. The error on the calibration based on inaccurate antenna heights over PEC showed the significant errors on the inversion results for the directive antenna (horn antenna) but less error for the bowtie antenna. This analysis demonstrated the general validity of the proposed far-field radar modeling approach, not only with respect to frequency and time domain radars but as well with respect to the calibrating medium. Numéro de notice : A2014-039 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2013.2243458 En ligne : https://doi.org/10.1109/TGRS.2013.2243458 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32944
in IEEE Transactions on geoscience and remote sensing > vol 52 n° 1 tome 2 (January 2014) . - pp 664 - 678[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2014011B RAB Revue Centre de documentation En réserve L003 Disponible Stem volume and above-ground biomass estimation of individual pine trees from LiDAR data: contribution of full-waveform signals / Tristan Allouis in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol 6 n° 2 part 3 (April 2013)PermalinkThe electronically steerable flash Lidar : A full waveform scanning system for topographic and ecosystem structure applications / H. Duong in IEEE Transactions on geoscience and remote sensing, vol 50 n° 11 Tome 2 (November 2012)PermalinkBuilding edge detection using small-footprint airborne full-waveform lidar data / Jean-Christophe Michelin in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol I-3 (2012)PermalinkPermalinkConditional random fields for urban scene : Classification with full waveform LiDAR Data / Joachim Niemeyer (2011)PermalinkRelevance of airborne lidar and multispectral image data for urban scene classification using random forests / Li Guo in ISPRS Journal of photogrammetry and remote sensing, vol 66 n° 1 (January - February 2011)PermalinkAnalyse de données lidar à retour d'onde complète pour la classification en milieu urbain = Analysis of Full-Waveform lidar data for urban area mapping / Clément Mallet (2010)PermalinkPermalinkAnalysis of full-waveform lidar data for classification of urban areas / Clément Mallet in Photogrammetrie Fernerkundung Geoinformation, vol 2008 n° 5 ([01/09/2008])PermalinkLe lidar topographique à retour d'onde complète: Etat de l'art / Clément Mallet in Traitement du signal, vol 24 n° 6 (01/12/2007)Permalink