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Auteur Lars M.H. Ulander |
Documents disponibles écrits par cet auteur (6)



Evaluating P-Band TomoSAR for biomass retrieval in boreal forest / Erik Blomberg in IEEE Transactions on geoscience and remote sensing, vol 59 n° 5 (May 2021)
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Titre : Evaluating P-Band TomoSAR for biomass retrieval in boreal forest Type de document : Article/Communication Auteurs : Erik Blomberg, Auteur ; Lars M.H. Ulander, Auteur ; Stefano Tebaldini, Auteur ; Laurent Ferro-Famil, Auteur Année de publication : 2021 Article en page(s) : pp 3793 - 3804 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bande P
[Termes IGN] biomasse forestière
[Termes IGN] forêt boréale
[Termes IGN] Suède
[Termes IGN] tomographie radarRésumé : (Auteur) P-band synthetic aperture radar (SAR) is sensitive to above-ground biomass (AGB) but retrieval accuracy has been shown to deteriorate in topographic areas. In boreal forest, the signal penetrates through the canopy to interact with the ground producing variations in backscatter depending on ground topography, forest structure, and soil moisture. Tomographic processing of multiple SAR images Tomographic SAR (TomoSAR) provides information about the vertical backscatter distribution. This article evaluates the use of P-band TomoSAR data to improve AGB retrievals from backscattered intensity by suppressing the backscattered signal from the ground. This approach can be used even when the tomographic resolution is insufficient to resolve the vertical backscatter profile. The analysis is based on P-band data from two campaigns: BioSAR-1 (2007) in Remingstorp, southern Sweden, and BioSAR-2 (2008) in Krycklan (KR), northern Sweden. BioSAR airborne data were also processed to correspond as closely as possible to future BIOMASS TomoSAR acquisitions, with BioSAR-2-based results shown. A power law AGB model using volumetric HV polarized backscatter performs best in KR, with training residual root mean-squared error (RMSE) of 30%–36% (27–33 t/ha) for airborne data and 38%–39% for simulated BIOMASS data. Airborne TomoSAR data suggest that both vertical and horizontal tomographic resolution are of importance and that it is possible to greatly reduce AGB retrieval bias when compared with airborne P-band SAR backscatter intensity-based retrievals. A lack of significant ground slopes in Remningstorp reduces the benefit of using TomoSAR data which performs similar to retrievals based solely on P-band SAR backscatter intensity. Numéro de notice : A2021-339 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2020.3020775 Date de publication en ligne : 22/09/2020 En ligne : https://doi.org/10.1109/TGRS.2020.3020775 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97570
in IEEE Transactions on geoscience and remote sensing > vol 59 n° 5 (May 2021) . - pp 3793 - 3804[article]Estimation of forest biomass from two-level model inversion of single-pass InSAR data / M.J. Soja in IEEE Transactions on geoscience and remote sensing, vol 53 n° 9 (September 2015)
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Titre : Estimation of forest biomass from two-level model inversion of single-pass InSAR data Type de document : Article/Communication Auteurs : M.J. Soja, Auteur ; Henrik J. Persson, Auteur ; Lars M.H. Ulander, Auteur Année de publication : 2015 Article en page(s) : pp 5083 - 5099 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] biomasse forestière
[Termes IGN] forêt boréale
[Termes IGN] image TanDEM-X
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] modèle numérique de terrain
[Termes IGN] placette d'échantillonnage
[Termes IGN] polarimétrie radar
[Termes IGN] SuèdeRésumé : (Auteur) A model for aboveground biomass estimation from single-pass interferometric synthetic aperture radar (InSAR) data is presented. Forest height and canopy density estimates Δh and η0, respectively, obtained from two-level model (TLM) inversion, are used as biomass predictors. Eighteen bistatic VV-polarized TanDEM-X (TDM) acquisitions are used, made over two Swedish test sites in the summers of 2011, 2012, and 2013 (nominal incidence angle: 41°; height-of-ambiguity: 32-63 m). Remningstorp features a hemiboreal forest in southern Sweden, with flat topography and where 32 circular plots have been sampled between 2010 and 2011 (area: 0.5 ha; biomass: 42-242 t/ha; height: 14-32 m) . Krycklan features a boreal forest in northern Sweden, 720-km north-northeast from Remningstorp, with significant topography and where 31 stands have been sampled in 2008 (area: 2.4-26.3 ha; biomass: 23-183 t/ha; height: 7-21 m). A high-resolution digital terrain model has been used as ground reference during InSAR processing. For the aforementioned plots and stands and if the same acquisition is used for model training and validation, the new model explains 65%-89% of the observed variance, with root-mean-square error (RMSE) of 12%-19% (median: 15%) . By fixing two of the three model parameters, accurate biomass estimation can also be done when different acquisitions or different test sites are used for model training and validation, with RMSE of 12%-56% (median: 17%). Compared with a simple scaling model computing biomass from the phase center elevation above ground, the proposed model shows significantly better performance in Remningstorp, as it accounts for the large canopy density variations caused by active management. In Krycklan, the two models show similar performance. Numéro de notice : A2015-525 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2417205 Date de publication en ligne : 24/04/2015 En ligne : https://doi.org/10.1109/TGRS.2015.2417205 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77536
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 9 (September 2015) . - pp 5083 - 5099[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2015091 SL Revue Centre de documentation Revues en salle Disponible Measurements of forest biomass change using P-Band synthetic aperture radar backscatter / Gustaf Sandberg in IEEE Transactions on geoscience and remote sensing, vol 52 n° 10 tome 1 (October 2014)
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Titre : Measurements of forest biomass change using P-Band synthetic aperture radar backscatter Type de document : Article/Communication Auteurs : Gustaf Sandberg, Auteur ; Lars M.H. Ulander, Auteur ; Jörgen Wallerman, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 6047 - 6061 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse diachronique
[Termes IGN] bande P
[Termes IGN] biomasse
[Termes IGN] détection de changement
[Termes IGN] données laser
[Termes IGN] forêt boréale
[Termes IGN] radar à antenne synthétique
[Termes IGN] rétrodiffusion
[Termes IGN] Suède
[Termes IGN] télédétection en hyperfréquenceRésumé : (Auteur) Methods to estimate forest biomass change have been investigated using experimental P-band synthetic aperture radar (SAR) data from the recent airborne campaigns BioSAR 2007 and BioSAR 2010 conducted over a hemiboreal test site in southern Sweden. Regression models based on backscatter change were developed using reference biomass change maps derived from high-density laser scanning data. Different regression models were developed for linear, square root, and logarithmic biomass change scales. The models were compared to the change maps based on laser data using twofold cross-validation, and estimation errors were evaluated using six 80 m by 80 m plots with detailed in situ measurements. The results indicate that the root-mean-square error of biomass change estimates based on P-band SAR backscatter data is about 15% or 20 t/ha. This suggests that not only clear-cuts but also growth and thinning can be measured. Simulations were performed in order to evaluate the possibility of using a spaceborne P-band SAR for measurements of forest biomass change. The simulations show that, with 64 equivalent number of looks (ENL) and a 50% change in biomass, it is possible to correctly indicate whether the forest has gained or lost biomass. Similarly, for a biomass loss of more than 75%, a correct indication of the sign of biomass change can be achieved with only 8 ENL. Numéro de notice : A2014-479 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2013.2294684 En ligne : https://doi.org/10.1109/TGRS.2013.2294684 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74060
in IEEE Transactions on geoscience and remote sensing > vol 52 n° 10 tome 1 (October 2014) . - pp 6047 - 6061[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2014101A RAB Revue Centre de documentation En réserve L003 Disponible On the retrieving of forest stem volume from VHF SAR data: observation and modeling / P. Melon in IEEE Transactions on geoscience and remote sensing, vol 39 n° 11 (November 2001)
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Titre : On the retrieving of forest stem volume from VHF SAR data: observation and modeling Type de document : Article/Communication Auteurs : P. Melon, Auteur ; J.M. Martinez, Auteur ; Thuy Le Toan, Auteur ; Lars M.H. Ulander, Auteur ; Alain Baudoin , Auteur
Année de publication : 2001 Article en page(s) : pp 2364 - 2372 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] coefficient de rétrodiffusion
[Termes IGN] données de terrain
[Termes IGN] forêt
[Termes IGN] image aérienne
[Termes IGN] image radar
[Termes IGN] masse végétale
[Termes IGN] modèle numérique de surface
[Termes IGN] Pinus (genre)
[Termes IGN] réalité de terrain
[Termes IGN] rétrodiffusion
[Termes IGN] télédétection en hyperfréquence
[Termes IGN] troncRésumé : (Auteur) The objective of this paper is to investigate the relationships between VHF data and forest biomass using data acquired by the Airborne Imaging Radar CARABAS over two different pine plantation forests in southern France. Data are analyzed using detailed ground truth measurements available on both sites. The backscattering coefficient is strongly correlated to characteristics of the tree trunk. Signal saturation is not observed up to 900 m' /ha. However, the sensitivity to the volume is high in the range of 0500 m' /ha (e.g., 1 to 1.5 dB for 50 m3/ha), whereas it is reduced beyond 500 m3/ha ( Numéro de notice : A2001-131 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/36.964972 En ligne : https://doi.org/10.1109/36.964972 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21827
in IEEE Transactions on geoscience and remote sensing > vol 39 n° 11 (November 2001) . - pp 2364 - 2372[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-01111 RAB Revue Centre de documentation En réserve L003 Disponible Interpretation of Seasat radar-altimeter data over sea ice using near-simultaneous SAR imagery / Lars M.H. Ulander in International Journal of Remote Sensing IJRS, vol 8 n° 11 (November 1987)
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Titre : Interpretation of Seasat radar-altimeter data over sea ice using near-simultaneous SAR imagery Type de document : Article/Communication Auteurs : Lars M.H. Ulander, Auteur Année de publication : 1987 Article en page(s) : pp 1679 - 1686 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photo-interprétation
[Termes IGN] altimètre radar
[Termes IGN] Arctique, océan
[Termes IGN] Beaufort, mer de
[Termes IGN] données altimétriques
[Termes IGN] glace de mer
[Termes IGN] image radar
[Termes IGN] photo-interprétation
[Termes IGN] radar à antenne synthétique
[Termes IGN] rétrodiffusion
[Termes IGN] SeasatNuméro de notice : A1987-362 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431168708954807 En ligne : https://doi.org/10.1080/01431168708954807 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=24435
in International Journal of Remote Sensing IJRS > vol 8 n° 11 (November 1987) . - pp 1679 - 1686[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-87111 RAB Revue Centre de documentation En réserve L003 Disponible Averaging of radar altimeter pulse returns with the interpolation tracker / Lars M.H. Ulander in International Journal of Remote Sensing IJRS, vol 8 n° 5 (May 1987)
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