Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX
Observing changes in Earth surface topography is crucial for many Earth science disciplines. Documenting these changes over several decades at regional to global scale remains a challenge due to the limited availability of suitable satellite data before the year 2000. Declassified analog satellite i...
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ftfrontimediafig:oai:figshare.com:article/13207463 2023-05-15T16:20:43+02:00 Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX Amaury Dehecq Alex S. Gardner Oleg Alexandrov Scott McMichael Romain Hugonnet David Shean Mauro Marty 2020-11-09T10:15:57Z https://doi.org/10.3389/feart.2020.566802.s002 https://figshare.com/articles/dataset/Table1_v1_Automated_Processing_of_Declassified_KH-9_Hexagon_Satellite_Images_for_Global_Elevation_Change_Analysis_Since_the_1970s_XLSX/13207463 unknown doi:10.3389/feart.2020.566802.s002 https://figshare.com/articles/dataset/Table1_v1_Automated_Processing_of_Declassified_KH-9_Hexagon_Satellite_Images_for_Global_Elevation_Change_Analysis_Since_the_1970s_XLSX/13207463 CC BY 4.0 CC-BY Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change stereo digital elevation model photogrammetry historical satellite imagery glacier changes uncertainty propagation Alaska European Alps Dataset 2020 ftfrontimediafig https://doi.org/10.3389/feart.2020.566802.s002 2020-11-11T23:56:15Z Observing changes in Earth surface topography is crucial for many Earth science disciplines. Documenting these changes over several decades at regional to global scale remains a challenge due to the limited availability of suitable satellite data before the year 2000. Declassified analog satellite images from the American reconnaissance program Hexagon (KH-9), which surveyed nearly all land surfaces from 1972 to 1986 at meter to sub-meter resolutions, provide a unique opportunity to fill the gap in observations. However, large-scale processing of analog imagery remains challenging. We developed an automated workflow to generate Digital Elevation Models and orthophotos from scanned KH-9 mapping camera stereo images. The workflow includes a preprocessing step to correct for film and scanning distortions and crop the scanned images, and a stereo reconstruction step using the open-source NASA Ames Stereo Pipeline. The processing of several hundreds of image pairs enabled us to estimate reliable camera parameters for each KH-9 mission, thereby correcting elevation biases of several tens of meters. The resulting DEMs were validated against various reference elevation data, including snow-covered glaciers with limited image texture. Pixel-scale elevation uncertainty was estimated as 5 m at the 68% confidence level, and less than 15 m at the 95% level. We evaluated the uncertainty of spatially averaged elevation change and volume change, both from an empirical and analytical approach, and we raise particular attention to large-scale correlated biases that may impact volume change estimates from such DEMs. Finally, we present a case study of long-term glacier elevation change in the European Alps. Our results show the suitability of these historical images to quantitatively study global surface change over the past 40–50 years. Dataset glacier glaciers Alaska Frontiers: Figshare |
institution |
Open Polar |
collection |
Frontiers: Figshare |
op_collection_id |
ftfrontimediafig |
language |
unknown |
topic |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change stereo digital elevation model photogrammetry historical satellite imagery glacier changes uncertainty propagation Alaska European Alps |
spellingShingle |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change stereo digital elevation model photogrammetry historical satellite imagery glacier changes uncertainty propagation Alaska European Alps Amaury Dehecq Alex S. Gardner Oleg Alexandrov Scott McMichael Romain Hugonnet David Shean Mauro Marty Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX |
topic_facet |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change stereo digital elevation model photogrammetry historical satellite imagery glacier changes uncertainty propagation Alaska European Alps |
description |
Observing changes in Earth surface topography is crucial for many Earth science disciplines. Documenting these changes over several decades at regional to global scale remains a challenge due to the limited availability of suitable satellite data before the year 2000. Declassified analog satellite images from the American reconnaissance program Hexagon (KH-9), which surveyed nearly all land surfaces from 1972 to 1986 at meter to sub-meter resolutions, provide a unique opportunity to fill the gap in observations. However, large-scale processing of analog imagery remains challenging. We developed an automated workflow to generate Digital Elevation Models and orthophotos from scanned KH-9 mapping camera stereo images. The workflow includes a preprocessing step to correct for film and scanning distortions and crop the scanned images, and a stereo reconstruction step using the open-source NASA Ames Stereo Pipeline. The processing of several hundreds of image pairs enabled us to estimate reliable camera parameters for each KH-9 mission, thereby correcting elevation biases of several tens of meters. The resulting DEMs were validated against various reference elevation data, including snow-covered glaciers with limited image texture. Pixel-scale elevation uncertainty was estimated as 5 m at the 68% confidence level, and less than 15 m at the 95% level. We evaluated the uncertainty of spatially averaged elevation change and volume change, both from an empirical and analytical approach, and we raise particular attention to large-scale correlated biases that may impact volume change estimates from such DEMs. Finally, we present a case study of long-term glacier elevation change in the European Alps. Our results show the suitability of these historical images to quantitatively study global surface change over the past 40–50 years. |
format |
Dataset |
author |
Amaury Dehecq Alex S. Gardner Oleg Alexandrov Scott McMichael Romain Hugonnet David Shean Mauro Marty |
author_facet |
Amaury Dehecq Alex S. Gardner Oleg Alexandrov Scott McMichael Romain Hugonnet David Shean Mauro Marty |
author_sort |
Amaury Dehecq |
title |
Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX |
title_short |
Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX |
title_full |
Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX |
title_fullStr |
Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX |
title_full_unstemmed |
Table1_v1_Automated Processing of Declassified KH-9 Hexagon Satellite Images for Global Elevation Change Analysis Since the 1970s.XLSX |
title_sort |
table1_v1_automated processing of declassified kh-9 hexagon satellite images for global elevation change analysis since the 1970s.xlsx |
publishDate |
2020 |
url |
https://doi.org/10.3389/feart.2020.566802.s002 https://figshare.com/articles/dataset/Table1_v1_Automated_Processing_of_Declassified_KH-9_Hexagon_Satellite_Images_for_Global_Elevation_Change_Analysis_Since_the_1970s_XLSX/13207463 |
genre |
glacier glaciers Alaska |
genre_facet |
glacier glaciers Alaska |
op_relation |
doi:10.3389/feart.2020.566802.s002 https://figshare.com/articles/dataset/Table1_v1_Automated_Processing_of_Declassified_KH-9_Hexagon_Satellite_Images_for_Global_Elevation_Change_Analysis_Since_the_1970s_XLSX/13207463 |
op_rights |
CC BY 4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3389/feart.2020.566802.s002 |
_version_ |
1766008695118888960 |