High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control
Unmanned aerial vehicles (UAVs) and structure from motion with multi-view stereo (SfM–MVS) photogrammetry are increasingly common tools for geoscience applications, but final product accuracy can be significantly diminished in the absence of a dense and well-distributed network of ground control poi...
Published in: | The Cryosphere |
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Online Access: | https://doi.org/10.5194/tc-13-955-2019 https://tc.copernicus.org/articles/13/955/2019/ |
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ftcopernicus:oai:publications.copernicus.org:tc73066 2023-05-15T16:21:33+02:00 High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control Chudley, Thomas R. Christoffersen, Poul Doyle, Samuel H. Abellan, Antonio Snooke, Neal 2019-03-19 application/pdf https://doi.org/10.5194/tc-13-955-2019 https://tc.copernicus.org/articles/13/955/2019/ eng eng doi:10.5194/tc-13-955-2019 https://tc.copernicus.org/articles/13/955/2019/ eISSN: 1994-0424 Text 2019 ftcopernicus https://doi.org/10.5194/tc-13-955-2019 2020-07-20T16:22:54Z Unmanned aerial vehicles (UAVs) and structure from motion with multi-view stereo (SfM–MVS) photogrammetry are increasingly common tools for geoscience applications, but final product accuracy can be significantly diminished in the absence of a dense and well-distributed network of ground control points (GCPs). This is problematic in inaccessible or hazardous field environments, including highly crevassed glaciers, where implementing suitable GCP networks would be logistically difficult if not impossible. To overcome this challenge, we present an alternative geolocation approach known as GNSS-supported aerial triangulation (GNSS-AT). Here, an on-board carrier-phase GNSS receiver is used to determine the location of photo acquisitions using kinematic differential carrier-phase positioning. The camera positions can be used as the geospatial input to the photogrammetry process. We describe the implementation of this method in a low-cost, custom-built UAV and apply the method in a glaciological setting at Store Glacier in western Greenland. We validate the technique at the calving front, achieving topographic uncertainties of ±0.12 m horizontally ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mspace width="0.125em" linebreak="nobreak"/><mn mathvariant="normal">1.1</mn><mo>×</mo></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="38pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="5da664611cc099a0e221dcd3bf096923"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-955-2019-ie00001.svg" width="38pt" height="10pt" src="tc-13-955-2019-ie00001.png"/></svg:svg> the ground sampling distance) and ±0.14 m vertically ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mspace width="0.125em" linebreak="nobreak"/><mn mathvariant="normal">1.3</mn><mo>×</mo></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="38pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="be021169700fe634fc5b31b32e824afe"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-955-2019-ie00002.svg" width="38pt" height="10pt" src="tc-13-955-2019-ie00002.png"/></svg:svg> the ground sampling distance), when flying at an altitude of ∼ 450 m above ground level. This compares favourably with previous GCP-derived uncertainties in glacial environments and allows us to apply the SfM–MVS photogrammetry at an inland study site where ice flows at 2 m day −1 and stable ground control is not available. Here, we were able to produce, without the use of GCPs, the first UAV-derived velocity fields of an ice sheet interior. Given the growing use of UAVs and SfM–MVS in glaciology and the geosciences, GNSS-AT will be of interest to those wishing to use UAV photogrammetry to obtain high-precision measurements of topographic change in contexts where GCP collection is logistically constrained. Text glacier Greenland Ice Sheet Copernicus Publications: E-Journals Greenland The Cryosphere 13 3 955 968 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Unmanned aerial vehicles (UAVs) and structure from motion with multi-view stereo (SfM–MVS) photogrammetry are increasingly common tools for geoscience applications, but final product accuracy can be significantly diminished in the absence of a dense and well-distributed network of ground control points (GCPs). This is problematic in inaccessible or hazardous field environments, including highly crevassed glaciers, where implementing suitable GCP networks would be logistically difficult if not impossible. To overcome this challenge, we present an alternative geolocation approach known as GNSS-supported aerial triangulation (GNSS-AT). Here, an on-board carrier-phase GNSS receiver is used to determine the location of photo acquisitions using kinematic differential carrier-phase positioning. The camera positions can be used as the geospatial input to the photogrammetry process. We describe the implementation of this method in a low-cost, custom-built UAV and apply the method in a glaciological setting at Store Glacier in western Greenland. We validate the technique at the calving front, achieving topographic uncertainties of ±0.12 m horizontally ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mspace width="0.125em" linebreak="nobreak"/><mn mathvariant="normal">1.1</mn><mo>×</mo></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="38pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="5da664611cc099a0e221dcd3bf096923"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-955-2019-ie00001.svg" width="38pt" height="10pt" src="tc-13-955-2019-ie00001.png"/></svg:svg> the ground sampling distance) and ±0.14 m vertically ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mspace width="0.125em" linebreak="nobreak"/><mn mathvariant="normal">1.3</mn><mo>×</mo></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="38pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="be021169700fe634fc5b31b32e824afe"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-955-2019-ie00002.svg" width="38pt" height="10pt" src="tc-13-955-2019-ie00002.png"/></svg:svg> the ground sampling distance), when flying at an altitude of ∼ 450 m above ground level. This compares favourably with previous GCP-derived uncertainties in glacial environments and allows us to apply the SfM–MVS photogrammetry at an inland study site where ice flows at 2 m day −1 and stable ground control is not available. Here, we were able to produce, without the use of GCPs, the first UAV-derived velocity fields of an ice sheet interior. Given the growing use of UAVs and SfM–MVS in glaciology and the geosciences, GNSS-AT will be of interest to those wishing to use UAV photogrammetry to obtain high-precision measurements of topographic change in contexts where GCP collection is logistically constrained. |
format |
Text |
author |
Chudley, Thomas R. Christoffersen, Poul Doyle, Samuel H. Abellan, Antonio Snooke, Neal |
spellingShingle |
Chudley, Thomas R. Christoffersen, Poul Doyle, Samuel H. Abellan, Antonio Snooke, Neal High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control |
author_facet |
Chudley, Thomas R. Christoffersen, Poul Doyle, Samuel H. Abellan, Antonio Snooke, Neal |
author_sort |
Chudley, Thomas R. |
title |
High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control |
title_short |
High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control |
title_full |
High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control |
title_fullStr |
High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control |
title_full_unstemmed |
High-accuracy UAV photogrammetry of ice sheet dynamics with no ground control |
title_sort |
high-accuracy uav photogrammetry of ice sheet dynamics with no ground control |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-955-2019 https://tc.copernicus.org/articles/13/955/2019/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet |
genre_facet |
glacier Greenland Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-13-955-2019 https://tc.copernicus.org/articles/13/955/2019/ |
op_doi |
https://doi.org/10.5194/tc-13-955-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
3 |
container_start_page |
955 |
op_container_end_page |
968 |
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1766009557719449600 |