Centre de documentation
scientifique

Brief communication: Glacier mapping and change estimation using very high-resolution declassified Hexagon KH-9 panoramic stereo imagery (1971-1984) / Sajid Ghuffar in The Cryosphere, vol 17 n° 3 (March 2023)  

Public [article]  inThe Cryosphere > vol 17 n° 3 (March 2023) . - pp 1299 - 1306 Titre : Brief communication: Glacier mapping and change estimation using very high-resolution declassified Hexagon KH-9 panoramic stereo imagery (1971-1984) Type de document : Article/Communication Auteurs : Sajid Ghuffar, Auteur ; Owen King, Auteur ; Grégoire Guillet, Auteur ; Ewelina Rupnik , Auteur ; Tobias Bolch, Auteur Année de publication : 2023 Article en page(s) : pp 1299 - 1306 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse diachronique [Termes IGN] glacier [Termes IGN] image Corona [Termes IGN] image panoramique [Termes IGN] image Pléiades-HR [Termes IGN] image SPOT Résumé : (auteur) The panoramic cameras (PCs) on board Hexagon KH-9 (KH-9PC) satellite missions from 1971–1984 captured very high-resolution stereo imagery with up to 60 cm spatial resolution. This study explores the potential of this imagery for glacier mapping and change estimation. We assess KH-9PC imagery using data from the KH-9 mapping camera (KH-9MC), KH-4PC, and SPOT and Pléiades satellite imagery. The high resolution of KH-9PC leads to higher-quality DEMs, which better resolve the accumulation region of the glaciers in comparison to the KH-9MC. On stable terrain, KH-9PC DEMs achieve an elevation accuracy of Numéro de notice : A2023-177 Affiliation des auteurs : UGE-LASTIG+Ext (2020- ) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/tc-17-1299-2023 Date de publication en ligne : 21/03/2023 En ligne : https://doi.org/10.5194/tc-17-1299-2023 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103285 [article]

A pipeline for automated processing of Corona KH-4 (1962-1972) stereo imagery / Sajid Ghuffar in IEEE Transactions on geoscience and remote sensing, vol 60 n° 8 (August 2022)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 60 n° 8 (August 2022) . - pp Titre : A pipeline for automated processing of Corona KH-4 (1962-1972) stereo imagery Type de document : Article/Communication Auteurs : Sajid Ghuffar, Auteur ; Tobias Bolch, Auteur ; Ewelina Rupnik , Auteur ; Atanu Bhattacharya, Auteur Année de publication : 2022 Article en page(s) : pp Note générale : bibliographie voir aussi https://research-repository.st-andrews.ac.uk/bitstream/10023/26124/1/Ghuffar_2022_IEEE_TGRS_Pipeline_automated_processing_AAM.pdf Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] appariement d'images [Termes IGN] apprentissage profond [Termes IGN] chaîne de traitement [Termes IGN] classification par réseau neuronal convolutif [Termes IGN] compensation par faisceaux [Termes IGN] géométrie de l'image [Termes IGN] géométrie épipolaire [Termes IGN] glacier [Termes IGN] Himalaya [Termes IGN] image Corona [Termes IGN] image panoramique [Termes IGN] MNS SRTM [Termes IGN] modèle numérique de surface [Termes IGN] modèle stéréoscopique [Termes IGN] point d'appui Résumé : (auteur) The Corona KH-4 reconnaissance satellite missions from 1962-1972 acquired panoramic stereo imagery with high spatial resolution of 1.8-7.5 m. The potential of 800,000+ declassified Corona images has not been leveraged due to the complexities arising from handling of panoramic imaging geometry, film distortions and limited availability of the metadata required for georeferencing of the Corona imagery. This paper presents Corona Stereo Pipeline (CoSP): A pipeline for processing of Corona KH-4 stereo panoramic imagery. CoSP utlizes a deep learning based feature matcher SuperGlue to automatically match features point between Corona KH-4 images and recent satellite imagery to generate Ground Control Points (GCPs). To model the imaging geometry and the scanning motion of the panoramic KH-4 cameras, a rigorous camera model consisting of modified collinearity equations with time dependent exterior orientation parameters is employed. The results show that using the entire frame of the Corona image, bundle adjustment using well-distributed GCPs results in an average standard deviation (SD) of less than 2 pixels. We evaluate fiducial marks on the Corona films and show that pre-processing the Corona images to compensate for film bending improves the accuracy. We further assess a polynomial epipolar resampling method for rectification of Corona stereo images. The distortion pattern of image residuals of GCPs and y-parallax in epipolar resampled images suggest that film distortions due to long term storage as likely cause of systematic deviations. Compared to the SRTM DEM, the Corona DEM computed using CoSP achieved a Normalized Median Absolute Deviation (NMAD) of elevation differences of ? 4m over an area of approx. 4000km2. We show that the proposed pipeline can be applied to sequence of complex scenes involving high relief and glacierized terrain and that the resulting DEMs can be used to compute long term glacier elevation changes over large areas. Numéro de notice : A2022-952 Affiliation des auteurs : UGE-LASTIG+Ext (2020- ) Autre URL associée : vers ArXiv Thématique : IMAGERIE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2022.3200151 Date de publication en ligne : 19/08/2022 En ligne : https://doi.org/10.1109/TGRS.2022.3200151 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103286 [article]

Modelling and compensating internal light scattering in time of flight range cameras / Wilfiried Karel in Photogrammetric record, vol 27 n° 138 (June - August 2012)  

Public [article]  inPhotogrammetric record > vol 27 n° 138 (June - August 2012) . - pp 155 - 174 Titre : Modelling and compensating internal light scattering in time of flight range cameras Type de document : Article/Communication Auteurs : Wilfiried Karel, Auteur ; Sajid Ghuffar, Auteur ; Norbert Pfeifer, Auteur Année de publication : 2012 Article en page(s) : pp 155 - 174 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] analyse comparative [Termes IGN] étalonnage de chambre métrique [Termes IGN] évaluation des paramètres [Termes IGN] propagation du signal [Termes IGN] temps de propagation Résumé : (Auteur) Time of flight range cameras simultaneously gather object distances for all pixels of a focal plane array by evaluating the round-trip time of an emitted signal. While ranging precisions typically amount to some centimeters, accuracies may be worse by an order of magnitude. Scattering is one of the sources of systematic errors, caused by the spreading of portions of the incident light over the sensor due to multiple reflections between the sensor, lens and optical filter. The present contribution analyses this phenomenon with respect to various capture parameters, with the objective of achieving a better understanding and a validation of assumptions. Subsequently, the authors derive both image space invariant and variant models for scattering, apply them to test scenes, and compare the results to each other and to those of existing methods. Numéro de notice : A2012-304 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/j.1477-9730.2012.00685.x Date de publication en ligne : 20/06/2012 En ligne : https://doi.org/10.1111/j.1477-9730.2012.00685.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31750 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
106-2012021	RAB	Revue	Centre de documentation	En réserve L003	Disponible