Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry
Airborne photogrammetry is undergoing a renaissance: lower-cost equipment, more powerful software, and simplified methods have significantly lowered the barriers to entry and now allow repeat mapping of cryospheric dynamics at spatial resolutions and temporal frequencies that were previously too exp...
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ftdoajarticles:oai:doaj.org/article:14fe28d58e604776a66c19cb3c526026 2023-05-15T18:32:31+02:00 Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry M. Nolan C. Larsen M. Sturm 2015-08-01T00:00:00Z https://doi.org/10.5194/tc-9-1445-2015 https://doaj.org/article/14fe28d58e604776a66c19cb3c526026 EN eng Copernicus Publications http://www.the-cryosphere.net/9/1445/2015/tc-9-1445-2015.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-9-1445-2015 https://doaj.org/article/14fe28d58e604776a66c19cb3c526026 The Cryosphere, Vol 9, Iss 4, Pp 1445-1463 (2015) Environmental sciences GE1-350 Geology QE1-996.5 article 2015 ftdoajarticles https://doi.org/10.5194/tc-9-1445-2015 2022-12-31T15:24:00Z Airborne photogrammetry is undergoing a renaissance: lower-cost equipment, more powerful software, and simplified methods have significantly lowered the barriers to entry and now allow repeat mapping of cryospheric dynamics at spatial resolutions and temporal frequencies that were previously too expensive to consider. Here we apply these advancements to the measurement of snow depth from manned aircraft. Our main airborne hardware consists of a consumer-grade digital camera directly coupled to a dual-frequency GPS; no inertial motion unit (IMU) or on-board computer is required, such that system hardware and software costs less than USD 30 000, exclusive of aircraft. The photogrammetric processing is done using a commercially available implementation of the structure from motion (SfM) algorithm. The system is simple enough that it can be operated by the pilot without additional assistance and the technique creates directly georeferenced maps without ground control, further reducing overall costs. To map snow depth, we made digital elevation models (DEMs) during snow-free and snow-covered conditions, then subtracted these to create difference DEMs (dDEMs). We assessed the accuracy (real-world geolocation) and precision (repeatability) of our DEMs through comparisons to ground control points and to time series of our own DEMs. We validated these assessments through comparisons to DEMs made by airborne lidar and by a similar photogrammetric system. We empirically determined that our DEMs have a geolocation accuracy of ±30 cm and a repeatability of ±8 cm (both 95 % confidence). We then validated our dDEMs against more than 6000 hand-probed snow depth measurements at 3 separate test areas in Alaska covering a wide-variety of terrain and snow types. These areas ranged from 5 to 40 km 2 and had ground sample distances of 6 to 20 cm. We found that depths produced from the dDEMs matched probe depths with a 10 cm standard deviation, and were statistically identical at 95 % confidence. Due to the precision of this ... Article in Journal/Newspaper The Cryosphere Alaska Directory of Open Access Journals: DOAJ Articles The Cryosphere 9 4 1445 1463 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 M. Nolan C. Larsen M. Sturm Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Airborne photogrammetry is undergoing a renaissance: lower-cost equipment, more powerful software, and simplified methods have significantly lowered the barriers to entry and now allow repeat mapping of cryospheric dynamics at spatial resolutions and temporal frequencies that were previously too expensive to consider. Here we apply these advancements to the measurement of snow depth from manned aircraft. Our main airborne hardware consists of a consumer-grade digital camera directly coupled to a dual-frequency GPS; no inertial motion unit (IMU) or on-board computer is required, such that system hardware and software costs less than USD 30 000, exclusive of aircraft. The photogrammetric processing is done using a commercially available implementation of the structure from motion (SfM) algorithm. The system is simple enough that it can be operated by the pilot without additional assistance and the technique creates directly georeferenced maps without ground control, further reducing overall costs. To map snow depth, we made digital elevation models (DEMs) during snow-free and snow-covered conditions, then subtracted these to create difference DEMs (dDEMs). We assessed the accuracy (real-world geolocation) and precision (repeatability) of our DEMs through comparisons to ground control points and to time series of our own DEMs. We validated these assessments through comparisons to DEMs made by airborne lidar and by a similar photogrammetric system. We empirically determined that our DEMs have a geolocation accuracy of ±30 cm and a repeatability of ±8 cm (both 95 % confidence). We then validated our dDEMs against more than 6000 hand-probed snow depth measurements at 3 separate test areas in Alaska covering a wide-variety of terrain and snow types. These areas ranged from 5 to 40 km 2 and had ground sample distances of 6 to 20 cm. We found that depths produced from the dDEMs matched probe depths with a 10 cm standard deviation, and were statistically identical at 95 % confidence. Due to the precision of this ... |
format |
Article in Journal/Newspaper |
author |
M. Nolan C. Larsen M. Sturm |
author_facet |
M. Nolan C. Larsen M. Sturm |
author_sort |
M. Nolan |
title |
Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry |
title_short |
Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry |
title_full |
Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry |
title_fullStr |
Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry |
title_full_unstemmed |
Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry |
title_sort |
mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/tc-9-1445-2015 https://doaj.org/article/14fe28d58e604776a66c19cb3c526026 |
genre |
The Cryosphere Alaska |
genre_facet |
The Cryosphere Alaska |
op_source |
The Cryosphere, Vol 9, Iss 4, Pp 1445-1463 (2015) |
op_relation |
http://www.the-cryosphere.net/9/1445/2015/tc-9-1445-2015.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-9-1445-2015 https://doaj.org/article/14fe28d58e604776a66c19cb3c526026 |
op_doi |
https://doi.org/10.5194/tc-9-1445-2015 |
container_title |
The Cryosphere |
container_volume |
9 |
container_issue |
4 |
container_start_page |
1445 |
op_container_end_page |
1463 |
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1766216626304188416 |