Luc Girod

• Filhol, Simon Vincent P; Girod, Luc Maurice Ramuntcho; Schuler, Thomas; Burkhart, John; Sutter, Guillaume & Perret, Alexis (2019). Time‐Lapse Photogrammetry of Distributed Snow Depth During Snowmelt. Water Resources Research.  ISSN 0043-1397.  55(9), s 7916- 7926 . doi: 10.1029/2018WR024530 Vis sammendrag

  Characterizing snowmelt both spatially and temporally from in situ observation remains a challenge. Available sensors (i.e., sonic ranger, lidar, airborne photogrammetry) provide either time series of local point measurements or sporadic surveys covering larger areas. We propose a methodology to recover from a minimum of three synchronized time-lapse cameras changes in snow depth and snow cover extent over area smaller or equivalent to 0.12 km2 . Our method uses photogrammetry to compute point clouds from a set of three or more images and automatically repeat this task for the entire time series. The challenges were (1) finding an optimal experimental setup deployable in the field, (2) estimating the error associated with this technique, and (3) being able to minimize the input of manual work in the data processing pipeline. Developed and tested in the field in Finse, Norway, over 1 month during the 2018 melt season, we estimated a median melt of 2.12 ± 0.48 m derived from three cameras 1.2 km away from the region of interest. The closest weather station recorded 1.94 m of melt. Other parameters like snow cover extent and duration could be estimated over a 300 × 400m region. The software is open source and applicable to a broader range of geomorphologic processes like glacier dynamic, snow accumulation, or any other processes of surface deformation, with the conditions of (1) having fixed visible points within the area of interest and (2) resolving sufficient surface textures in the photographs.

• Nuth, Christopher; Gilbert, Adrien; Köhler, Andreas; McNabb, Robert Whitfield; Schellenberger, Thomas; Sevestre, Heidi; Weidle, Christian; Girod, Luc Maurice Ramuntcho; Luckman, Adrian & Kääb, Andreas (2019). Dynamic vulnerability revealed in the collapse of an Arctic tidewater glacier. Scientific Reports.  ISSN 2045-2322.  9 . doi: 10.1038/s41598-019-41117-0
• Girod, Luc Maurice Ramuntcho; Nielsen, Niels Ivar; Couderette, Frédérique; Nuth, Christopher & Kääb, Andreas (2018). Precise DEM extraction from Svalbard using 1936 high oblique imagery. Geoscientific Instrumentation, Methods and Data Systems.  ISSN 2193-0856.  7, s 277- 288 . doi: 10.5194/gi-7-277-2018
• McNabb, Robert Whitfield; Nuth, Christopher; Kääb, Andreas & Girod, Luc Maurice Ramuntcho (2018). Sensitivity of geodetic glacier mass balance estimation to DEM void interpolation. The Cryosphere Discussions.  ISSN 1994-0432.
• Robson, Benjamin Aubrey; Nuth, Christopher; Nielsen, Pål Ringkjøb; Girod, Luc Maurice Ramuntcho; Hendrickx, Marijn & Dahl, Svein Olaf (2018). Spatial variability in patterns of glacier change across the Manaslu Range, Central Himalaya. Frontiers in Earth Science.  ISSN 2296-6463.  6 . doi: 10.3389/feart.2018.00012 Fulltekst i vitenarkiv.
• Girod, Luc Maurice Ramuntcho; Nuth, Christopher; Kääb, Andreas; Etzelmüller, Bernd & Kohler, Jack (2017). Terrain changes from images acquired on opportunistic flights by SfM photogrammetry. The Cryosphere.  ISSN 1994-0416.  11(2), s 827- 840 . doi: 10.5194/tc-11-827-2017 Fulltekst i vitenarkiv.
• Girod, Luc Maurice Ramuntcho; Nuth, Christopher; Kääb, Andreas; McNabb, Robert Whitfield & Galland, Olivier (2017). MMASTER: Improved ASTER DEMs for elevation change monitoring. Remote Sensing.  ISSN 2072-4292.  9(7) . doi: 10.3390/rs9070704 Fulltekst i vitenarkiv.
• Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke Færøvik; Bjugger, Fanny; Burchardt, Steffi & Mair, Karen (2016). Application of open-source photogrammetric software MicMac for monitoring surface deformation in laboratory models. Journal of Geophysical Research (JGR): Solid Earth.  ISSN 2169-9313.  121(4), s 2852- 2872 . doi: 10.1002/2015JB012564
• Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas (2016). Glacier volume change estimation using time series of improved ASTER DEMs. International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences.  ISSN 1682-1750.  41(B8), s 489- 494 . doi: 10.5194/isprsarchives-XLI-B8-489-2016
• Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas (2015). Improvement of DEM generation from ASTER images using satellite jitter estimation and open source implementation. International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences.  ISSN 1682-1750.  40(1), s 249- 253 . doi: 10.5194/isprsarchives-XL-1-W5-249-2015
• Girod, Luc Maurice Ramuntcho & Pierrot-Deseilligny, Marc (2014). Égalisation radiométrique de nuages de points 3D issus de corrélation dense. Revue Francaise de Photogrammetrie et de Teledetection.  ISSN 1768-9791.  (206), s 3- 14
• Kääb, Andreas; Girod, Luc Maurice Ramuntcho & Berthling, Ivar Thoralf (2014). Surface kinematics of periglacial sorted circles using Structure-from-Motion technology. The Cryosphere Discussions.  ISSN 1994-0432.  7, s 6043- 6074 . doi: 10.5194/tcd-7-6043-2013 Fulltekst i vitenarkiv.
• Kääb, Andreas; Girod, Luc Maurice Ramuntcho & Berthling, Ivar Thoralf (2014). Surface kinematics of periglacial sorted circles using structure-from-motion technology. The Cryosphere.  ISSN 1994-0416.  8(3), s 1041- 1056 . doi: 10.5194/tc-8-1041-2014 Fulltekst i vitenarkiv.

Se alle arbeider i Cristin

• Girod, Luc Maurice Ramuntcho (2018). Improved measurements of cryospheric processes using advanced photogrammetry. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1948. 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.

• Girod, Luc Maurice Ramuntcho; Nielsen, Niels Ivar; Couderette, Frédérique; Hoslt, Marion Dominique; Lazizi, Laetitia Alice; Nuth, Christopher & Kääb, Andreas (2018). Extraction of glacier thickness change data and communication material from historical oblique imagery.
• Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke F.; Bjugger, Fanny; Burchardt, Steffi & Mair, Karen (2017). Application of open-source photogrammetric software MicMac for geodetic monitoring in laboratory models.
• Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke Færøvik; Bjugger, Fanny; Burchardt, Steffi & Mair, Karen (2017). Application of open-source photogrammetric software MicMac for geodetic monitoring in laboratory models.
• 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.
• Kääb, Andreas; Treichler, Désirée Silvana; Girod, Luc Maurice Ramuntcho; Lefeuvre, Pierre-Marie; Schellenberger, Thomas; Altena, Bas; Jonassen, Vetle; Nuth, Christopher; McNabb, Robert Whitfield & Gilbert, Adrien (2016). On the Karakoram anomaly.
• Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke Færøvik; Bjugger, Fanny; Burchardt, Steffi & Mair, Karen (2016). Laboratory geodesy : Application of open-source photogrammetric software MicMac for monitoring surface deformation in laboratory models.
• Galland, Olivier; Bertelsen, Håvard Svanes; Guldstrand, Frank Bo Buster; Girod, Luc Maurice Ramuntcho; Johannessen, Rikke Færøvik; Bjugger, Fanny; Burchardt, Steffi & Mair, Karen (2016). Laboratory geodesy: Application of open-source photogram-metric software MicMac to monitoring surface deformation in laboratory models.
• Girod, Luc Maurice Ramuntcho; Kääb, Andreas & Berthling, Ivar Thoralf (2016). Surface kinematics of periglacial sorted circles over 8 years using SfM close-range photogrammetry.
• Girod, Luc Maurice Ramuntcho & Nilsen, Irene Brox (2016). ClimaByte, an Educational Youtube Channel About Climate Sciences. [Video ]. Vis sammendrag

  ClimaByte is an educational YouTube Channel that will explore numerous subjects related to climate sciences, geosciences and the tools associated with them. This channel is created by young scientists at the University of Oslo, Norway.

• Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas (2016). Enhanced ASTER DEMs for Decadal Measurments of Glacier Elevation Changes.
• Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas (2016). Glacier volume change estimation using time series of improved ASTER DEMs.
• Girod, Luc Maurice Ramuntcho; Nuth, Christopher & Kääb, Andreas (2016). Opportunistic survey of glaciers using GoPros and helicopters.
• Girod, Luc Maurice Ramuntcho; Nuth, Christopher; Kääb, Andreas; Etzelmüller, Bernd & Kohler, Jack (2016). Terrain changes from images acquired on opportunistic flights by SFM photogrammetry.
• Kääb, Andreas; Girod, Luc Maurice Ramuntcho & Berthling, Ivar Thoralf (2016). Surface kinematics of periglacial sorted circles over 8 years using SfM close range photogrammetry.
• Nuth, Christopher; Girod, Luc Maurice Ramuntcho; Kohler, Jack; Bahr, Kenneth & Karlsen, Tor Ivan (2016). Detailed glacier crevasse morphology mapped by helicopter.
• 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.
• Girod, Luc Maurice Ramuntcho; Gautrais, Olivia; Nuth, Christopher & Kohler, Jack (2015). Structure from motion: a low cost, very high resolution method for surveying glaciers.
• 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.

Se alle arbeider i Cristin