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Ignatiuk, Dariusz; Dunse, Thorben; Gallet, Jean-Charles; Girod, Luc; Kępski, Daniel & Laska, Michał
[Vis alle 12 forfattere av denne artikkelen]
(2023).
Snow_GPR: Ground penetrating radar measurement of snow in Svalbard - past, present, future. .
I SIOS, SESS Report (Red.),
SESS report 2022.
Svalbard Integrated Arctic Earth Observing System.
ISSN 978-82-93871-06-4.
doi:
10.5281/zenodo.7371725.
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Treichler, Désirée; Mazzolini, Marco; Piermattei, Livia; Webster, Clare; Girod, Luc & Aalstad, Kristoffer
[Vis alle 7 forfattere av denne artikkelen]
(2023).
SNOWDEPTH: Spaceborne snow depth measurements from ICESat-2 laser altimetry and data assimilation.
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Treichler, Désirée; Mazzolini, Marco; Piermattei, Livia; Webster, Clare & Girod, Luc
(2022).
Spaceborne snow depth measurements from ICESat-2 laser altimetry.
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Huiban, Flora; Dømgaard, Mads; Girod, Luc; Millan, Roman; Dehecq, Amaury & Mouginot, Jeremie
[Vis alle 9 forfattere av denne artikkelen]
(2022).
Expanding glacier time series of Antarctica and Greenland using Soviet Era KFA-1000 satellite images.
EGU General Assembly.
doi:
10.5194/egusphere-egu22-7374.
Vis sammendrag
Long-term records of glaciers are more than ever crucial to understand their response to climate change. High-quality photogrammetric products, Digital Elevation Models (DEMs) and orthophotographs from early satellites are essential, as they offer a unique high-resolution view on the historical glacial dynamics. However, obtaining and producing high-resolution datasets from historical imagery can be a challenge.
In our study, we are extending available satellite images time series using images from Soviet Era KFA-1000 satellite cameras. Each KFA-1000 has a 1000 mm objective, holding 1800 frames in its magazine. Each frame is typically 18x18 cm or 30 × 30 cm, with an 80 km swath width, providing panchromatic images. They supplement the very sparse data period between aerial images and high-resolution modern satellites, giving us high-resolution insight of Antarctica and Greenland dating from 1974 to 1994. Since these images have been largely underused, they have the potential to improve our knowledge of glaciers and open new scientific perspectives. They could help us improve models in studies regarding, for instance the frontal position, the flow-velocity (by doing feature tracking), the surface elevation or the grounding line of the glaciers, etc. With a spatial resolution up to 2 m and images recorded in stereo geometry, they offer a valuable complement to other historical satellite archives such as the declassified American KH imagery. Here, we use structure-from-motion (SfM) to reconstruct former glacier surfaces and flow of main outlet glaciers in both Antarctica and Greenland. We compare and assess the quality of the results by comparing the produced DEMs with recent high-resolution imagery from Worldview’s ArcticDEM. We combine the historical DEMs with recent satellite imagery of the ice elevation and reconstruct the comprehensive history of volume change over southeast and northeast Greenland glaciers since the 90s. Mostly lost from sight for 50 years, we are now resurrecting these highly valuable records and will make them freely available to science and the public.
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Hugonnet, Romain; McNabb, Robert Whitfield; Berthier, Etienne; Menounos, B.; Nuth, Christopher & Girod, Luc Maurice Ramuntcho
[Vis alle 10 forfattere av denne artikkelen]
(2020).
A globally complete, spatially and temporally resolved estimate of glacier mass change: 2000 to 2019.
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McNabb, Robert Whitfield; Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas
(2020).
An open-source toolset for automated processing of historic spy photos: sPyMicMac.
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Hugonnet, Romain; McNabb, Robert Whitfield; Berthier, Etienne; Menounos, B; Nuth, Christopher & Girod, Luc Maurice Ramuntcho
[Vis alle 10 forfattere av denne artikkelen]
(2020).
Accelerated global glacier mass loss in the early twenty-first century.
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Child, Sarah F.; Scambos, Ted A; Fahnestock, M; Alley, Karen E; Stearns, Leigh A & Girod, Luc Maurice Ramuntcho
(2020).
Historical hypsometry analysis of the Dotson and Crosson Ice Shelves using trimetrogon aerial imagery with structure-from-motion processing techniques.
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Alley, Karen E; Wild, Christian Thomas; Girod, Luc Maurice Ramuntcho; Luckman, Adrian; Child, Sarah F. & Hulen, Cyrus
[Vis alle 12 forfattere av denne artikkelen]
(2020).
Two decades of dynamic changes on the Thwaites Eastern Ice Shelf.
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Girod, Luc Maurice Ramuntcho; Nielsen, Niels Ivar; Couderette, Frédérique; Hoslt, Marion Dominique; Lazizi, Laetitia Alice & Nuth, Christopher
(2018).
Extraction of glacier thickness change data and communication material from historical oblique imagery.
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Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke F. & Bjugger, Fanny
[Vis alle 8 forfattere av denne artikkelen]
(2017).
Application of open-source photogrammetric software MicMac for geodetic monitoring in laboratory models.
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Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke Færøvik & Bjugger, Fanny
[Vis alle 8 forfattere av denne artikkelen]
(2017).
Application of open-source photogrammetric software MicMac for geodetic monitoring in laboratory models.
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Nuth, Christopher; Girod, Luc Maurice Ramuntcho; Winsvold, Solveig Havstad; Deschamps Berger, Cesar; Berthier, Etienne & Kääb, Andreas
(2016).
Remote Sensing in Ny Ålesund: Products, purpose and validation.
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Nuth, Christopher; Girod, Luc Maurice Ramuntcho; Kohler, Jack; Bahr, Kenneth & Karlsen, Tor Ivan
(2016).
Detailed glacier crevasse morphology mapped by helicopter.
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Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas
(2016).
Enhanced ASTER DEMs for Decadal Measurments of Glacier Elevation Changes.
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Girod, Luc Maurice Ramuntcho; Couderette, Frédérique; Aas, Harald Faste & Nuth, Christopher
(2016).
Historical oblique images of Svalbard : DEM of the Archipelago's glaciers in 1936.
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Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas
(2016).
Glacier volume change estimation using time series of improved ASTER DEMs.
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Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas
(2016).
Opportunistic survey of glaciers using GoPros and helicopters.
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Kääb, Andreas; Girod, Luc Maurice Ramuntcho & Berthling, Ivar Thoralf
(2016).
Surface kinematics of periglacial sorted circles
over 8 years using SfM close range photogrammetry.
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Girod, Luc Maurice Ramuntcho; Kääb, Andreas & Berthling, Ivar Thoralf
(2016).
Surface kinematics of periglacial sorted circles over 8 years
using SfM close-range photogrammetry.
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Girod, Luc Maurice Ramuntcho; Nuth, Christopher; Kääb, Andreas; Etzelmüller, Bernd & Kohler, Jack
(2016).
Terrain changes from images acquired on opportunistic flights by SFM photogrammetry.
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Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke Færøvik & Bjugger, Fanny
[Vis alle 8 forfattere av denne artikkelen]
(2016).
Laboratory geodesy : Application of open-source photogrammetric software MicMac for monitoring surface deformation in laboratory models.
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Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke Færøvik & Bjugger, Fanny
[Vis alle 8 forfattere av denne artikkelen]
(2016).
Laboratory geodesy: Application of open-source photogram-metric software MicMac to monitoring surface deformation in laboratory models.
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Girod, Luc Maurice Ramuntcho; Gautrais, Olivia; Nuth, Christopher & Kohler, Jack
(2015).
Structure from motion: a low cost, very high resolution method for surveying glaciers.
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Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Schellenberger, Thomas
(2014).
Structure from motion, a low cost, very high resolution method for surveying glaciers using GoPros and opportunistic helicopter flights.
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Girod, Luc Maurice Ramuntcho
(2018).
Improved measurements of cryospheric processes using advanced photogrammetry.
Universitetet i Oslo.
ISSN 1501-7710.
Fulltekst i vitenarkiv
Vis sammendrag
The cryosphere is defined as the areas of the Earth where water is found frozen. The notion of cryospheric processes relates to glaciers, ice caps, ice sheets, ice shelves, sea ice and permafrost. Cryospheric processes are often used as indicators of a changing climate since they respond relatively fast to climate change: sea ice extent decreases, ice shelves and glaciers retreat, permafrost thaws...Therefore, understanding these processes is critical to the understanding of the causes and effects of climate change.
Photogrammetry, the science of making geometric and radiometric measurements using photographic imagery, has a century-long history of providing data for geoscience research. Indeed, it is an incredible tool to produce data for the study of processes of interest, in the form of digital elevation models to study their geometry, or in the form of orthoimages to study their texture. If imagery data of the same scene can be acquired at different moments in time, it is possible to create time series. Series of measurements allows for the study and understanding of the evolution of a process through time.
This thesis presents work done in the development and application of leading edge photogrammetric methods to the measurement of cryopsheric processes, going through the different scales at which these processes are active, starting at the largest scale with the camera closest to the ground for the study of the meter scale and gradually getting a larger view. Close range photogrammetry was used for the study of the meter scale permafrost process of sorted circles, light airborne imaging was used for the study of a small glacier called Midtre Lovénbreen and its periglacial area, historical heavy airborne survey was used for a more regional survey of Prins Karl Forland and a satellite imaging processing workflow was developed to allow for the study of global scale changes. Thanks to recent developments in photogrammetry, including those presented in this thesis, data quality is on the rise. The key conclusions of this work are that (1) it is possible to push the limit of the precision of the elevation data obtained from imagery by applying modern, improved methods, and (2) that, with these methods, all sorts of image sources can be exploited in order to acquire data on various processes of interest. We used images that we acquired ourselves using consumer grade tools, images found by digging through historical airborne survey archives, and images obtained using spaceborne instruments. That second objective is complemented with the open-source availability of the software and methods developed in the context of this PhD in order to facilitate their use by the scientific community.