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Study of the geometry effect on land surface temperature retrieval in urban environment / Jinxin Yanga in ISPRS Journal of photogrammetry and remote sensing, vol 109 (November 2015)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 109 (November 2015) . - pp77 - 87 Titre : Study of the geometry effect on land surface temperature retrieval in urban environment Type de document : Article/Communication Auteurs : Jinxin Yanga, Auteur ; Man Sing Wong, Auteur ; Massimo Menenti, Auteur ; Janet Nichol, Auteur Année de publication : 2015 Article en page(s) : pp77 - 87 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] canyon urbain [Termes IGN] exitance spectrale [Termes IGN] géométrie de l'image [Termes IGN] milieu urbain [Termes IGN] réflectance urbaine [Termes IGN] température au sol Résumé : (auteur) This study presents a Single Channel Method using Urban Exitance Model (UEM-SCM) to retrieve land surface temperature (LST) from satellite data in an urbanized city, and evaluates the geometry effect on land surface temperature retrieval using single channel method and split-window algorithm. The UEM-SCM incorporates the effect of urban geometry and considers both reflection caused by the target pixel and its neighboring pixels. In order to evaluate the geometry effect, the retrieved LSTs with and without geometry effect were studied. Results show that the LSTs without geometry effect are generally higher than the LSTs with geometry effect. The temperature difference occurs because the material emissivity is always lower than the effective emissivity caused by multiple scattering and reflection in urban areas (cavity effect). The LST without geometry effect also cannot fully capture the variability and complexity of urban thermal patterns. The temperature difference between with and without the geometry effect can reach 2 K in built-up areas. A comparison was also conducted between LST retrieved by split-window algorithm with and without geometry effect. Results show that the LST retrieved by split-window algorithm without geometry effect has generally higher values than the one with the geometry effect, e.g. 1.1 K on average and 1.5–2 K in built-up areas. The geometry effect will be removed and mis-deemed as atmospheric effect when the split-window algorithm without geometry effect is applied in urban areas. The split-window algorithm with the geometry effect can be used to distinguish between geometry and atmospheric effect in further study. Numéro de notice : A2015-859 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2015.09.001 En ligne : http://dx.doi.org/10.1016/j.isprsjprs.2015.09.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79238 [article]

Forest biomass estimation using texture measurements of high-resolution dual-polarization C-band SAR data / Latifur Rahman Sarker in IEEE Transactions on geoscience and remote sensing, vol 51 n° 6 Tome 1 (June 2013)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 51 n° 6 Tome 1 (June 2013) . - pp 3371 - 3384 Titre : Forest biomass estimation using texture measurements of high-resolution dual-polarization C-band SAR data Type de document : Article/Communication Auteurs : Latifur Rahman Sarker, Auteur ; Janet Nichol, Auteur ; Husseyin Baki Iz, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 3371 - 3384 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] angle d'incidence [Termes IGN] bande C [Termes IGN] biomasse forestière [Termes IGN] données de terrain [Termes IGN] forêt tropicale [Termes IGN] image Radarsat [Termes IGN] polarimétrie radar [Termes IGN] polarisation croisée [Termes IGN] teneur en carbone [Termes IGN] texture d'image Résumé : (Auteur) Recent synthetic aperture radar (SAR) sensors with a capability of providing data with varying spatial resolutions, polarizations, and incidence angles have attracted greater interest for forest biomass and carbon storage estimation. This study investigates the capability of RADARSAT-2 fine-beam dual-polarization (C-HV and C-HH) data for forest biomass estimation in complex subtropical forest, with different types of processing: 1) raw intensity data (both polarizations separately and as polarization ratio) and 2) texture parameters of both polarizations (separately, jointly, and as polarization ratio). Field data (diameter at breast height and height) were collected from 53 field plots and converted to biomass (dry weight) using a newly developed allometric model. Finally, biomass estimation models were developed between SAR signatures from different processing steps and field plot biomass using stepwise multiple regression. All biomass estimation models using radar intensity data (C-HV, C-HH, and ratio of C-HV and C-HH) proved ineffective, but texture parameters derived from intensity data showed potential. We were able to estimate forest biomass amounts up to 360 t/ha with a goodness of fit of 0.78 (adjusted r2) and an rmse of 28.68 t/ha using the combination of texture parameters of both polarizations (C-HV and C-HH). However, goodness of fit could be improved to 0.91 (adjusted r2) and an rmse of 26.95 t/ha for biomass levels up to 532 t/ha using the ratio of texture parameters of C-HV/C-HH. The result is very encouraging and indicates that the dual-polarization C-band SAR sensor has a potential for the estimation of forest biomass, particularly using the polarization ratio of texture measurements, and biomass estimation can be improved substantially beyond the previously stated saturation level for C-band SAR. Numéro de notice : A2013-300 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2219872 En ligne : https://doi.org/10.1109/TGRS.2012.2219872 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32438 [article]

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065-2013061A	RAB	Revue	Centre de documentation	En réserve L003	Disponible