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Auteur Juha Karvonen |
Documents disponibles écrits par cet auteur



Incidence angle dependence of first-year sea ice backscattering coefficient in Sentinel-1 SAR Imagery over the kara sea / Marko P. Mäkynen in IEEE Transactions on geoscience and remote sensing, vol 55 n° 11 (November 2017)
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Titre : Incidence angle dependence of first-year sea ice backscattering coefficient in Sentinel-1 SAR Imagery over the kara sea Type de document : Article/Communication Auteurs : Marko P. Mäkynen, Auteur ; Juha Karvonen, Auteur Année de publication : 2017 Article en page(s) : pp 6170 - 6181 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes descripteurs IGN] angle d'incidence
[Termes descripteurs IGN] coefficient de rétrodiffusion
[Termes descripteurs IGN] données polarimétriques
[Termes descripteurs IGN] image radar moirée
[Termes descripteurs IGN] polarimétrie radar
[Termes descripteurs IGN] régression linéaireRésumé : (Auteur) We have studied the incidence angle (θ0) dependence of the sea ice backscattering coefficient (0.°) for Sentinel-1 (S-1) extra wide (EW) mode dualpolarization (HH/HV) synthetic aperture radar (SAR) imagery acquired over the Kara Sea under winter and summer melting conditions. The determination of the 0.° versus θ0 dependence was based on SAR image pairs acquired on ascending and descending orbits over the same sea ice area with a short time difference. The SAR noise floor was subtracted from the HV images. From the image pairs 1.1 by 1.1 km windows representing level first-year ice (LFYI) and deformed first-year ice (DFYI) were manually selected, and a linear regression was fit between the resulting 0.° and θ0 differences of the windows to estimate the slope b1 (dB/1°) between 0.° and θ0. For example, under winter condition b1 for DFYI at HHand HV-polarizations was found to be -0.24 and -0.16 dB/1°, respectively, and b1 for LFYI at HH-polarization was -0.25 dB/1°. It was not possible to determine a reliable b1 for LFYI at HV due to a contamination effect of the S-1 noise floor. The b1 values at HH compared well with previous studies. They can be used to compensate the 0.° incidence angle variation in the S-1 EW SAR images with good accuracy. The HH b1 values are applicable to other S-1 imaging modes and other C-band SAR sensors like RADARSAT-2. Unfortunately, the HV b1 values are specific to the S-1 EW mode due to the noise floor problem. Numéro de notice : A2017-744 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2017.2720664 En ligne : https://doi.org/10.1109/TGRS.2017.2720664 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88778
in IEEE Transactions on geoscience and remote sensing > vol 55 n° 11 (November 2017) . - pp 6170 - 6181[article]Baltic sea ice concentration estimation using SENTINEL-1 SAR and AMSR2 microwave radiometer data / Juha Karvonen in IEEE Transactions on geoscience and remote sensing, vol 55 n° 5 (May 2017)
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Titre : Baltic sea ice concentration estimation using SENTINEL-1 SAR and AMSR2 microwave radiometer data Type de document : Article/Communication Auteurs : Juha Karvonen, Auteur Année de publication : 2017 Article en page(s) : pp 2871 - 2883 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes descripteurs IGN] analyse comparative
[Termes descripteurs IGN] Baltique, mer
[Termes descripteurs IGN] épaisseur de la glace
[Termes descripteurs IGN] glace de mer
[Termes descripteurs IGN] image Aqua-AMSR
[Termes descripteurs IGN] image Sentinel-SAR
[Termes descripteurs IGN] navigation maritime
[Termes descripteurs IGN] Sentinel-1
[Termes descripteurs IGN] télédétection en hyperfréquenceRésumé : (Auteur) Sea ice concentration (SIC) is an important sea ice parameter for sea ice navigation, environmental research, and weather and ice forecasting. We have developed and tested a method for estimation of the Baltic Sea SIC using SENTINEL-1 synthetic aperture radar (SAR) and Advanced Microwave Scanning Radiometer 2 passive microwave radiometer (MWR) data. Here, we present the method and results for January 2016. Ice concentration grids of Finnish Meteorological Institute daily ice charts have been used as reference data in this paper. We present a comparison of four SIC estimation methods with our reference data. In addition to the combined SAR/MWR SIC estimation method, we also compare SIC estimates produced using SAR alone and two MWR-based methods. The main target of this paper was to develop and test a high-resolution SIC estimation method suitable for operational use. Numéro de notice : A2017-470 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://dx.doi.org/10.1109/TGRS.2017.2655567 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86393
in IEEE Transactions on geoscience and remote sensing > vol 55 n° 5 (May 2017) . - pp 2871 - 2883[article]