digital surface model: DSMs represent surface elevations of all surfaces, including vegetation, vegetation-free land, bridges, buildings, etc. The DSM is a single-band, 32-bit float GeoTIFF file using Lempel-Ziv-Welch (LZW) compression, with a ground sample distance (GSD) of 0.21 m. "No Data" value is set to -32767. orthoimage: The orthoimage is a three-band, 8-bit unsigned GeoTIFF file using LZW compression. The orthoimage has a GSD of 0.21 m per pixel, and the "No Data" value is set to 0. Variable lighting in the orthoimages may result from variable sky conditions during the time of data acquisition.
Wolken, G.J., Wikstrom Jones, Katreen, Whorton, E.N., Gould, A.I., and Hendricks, M.D., 2017, Photogrammetric data of the Haines Highway corridor: May 26, 2014: Raw Data File RDF 2017-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
This is a raster data set.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest .00000001
Ordinates (y-coordinates) are specified to the nearest .00000001
Planar coordinates are specified in Meters
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is GRS 80.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257222101000025.
This project is funded by the State of Alaska Department of Transportation & Public Facilities and a State of Alaska Capital Improvement Project.
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In 2014, the Alaska Division of Geological & Geophysical Surveys (DGGS) began a collaborative study with the Alaska Department of Transportation & Public Facilities (DOT&PF) along the Haines Highway corridor near Haines, Alaska. The intent of this study is to evaluate, monitor, and model geophysical processes, including cryosphere-related changes, along this important transportation corridor where destructive debris flows regularly impact the highway by threatening motorists, damaging infrastructure, and impeding traffic flow. Repeat aerial photography and digital surface model (DSM) generation of this dynamic catchment is the first step to allow DGGS to quantify debris volumes, understand the source of the debris flows, and provide guidance to DOT&PF planners for mitigating the hazard to the roadway.
DSMs represent surface elevations of all surfaces, including vegetation, vegetation-free land, bridges, buildings, etc. The DSM is a single-band, 32-bit float GeoTIFF file using Lempel-Ziv-Welch (LZW) compression, with a ground sample distance (GSD) of 0.21 m. "No Data" value is set to -32767. The orthoimage is a three-band, 8-bit unsigned GeoTIFF file using LZW compression. The orthoimage has a GSD of 0.21 m per pixel, and the "No Data" value is set to 0. Variable lighting in the orthoimages may result from variable sky conditions during the time of data acquisition.
Horizontal accuracy of the DSM was assessed by comparing the locations of ten checkpoints to the same point in the co-registered orthoimagery. The mean offset (residual) was -0.14 m in the X-direction and -0.02 m in the Y-direction, with a standard deviation of 0.29 (0.20, Y-direction) and a root-mean-square error (RMSE) of 0.31 (0.27, Y-direction). No horizontal transformation was applied because horizontal offsets were not identified at or above the pixel scale (i.e., 0.21 m GSD). Horizontal accuracy of the orthoimagery was assessed by comparing the locations of ten checkpoints to the same point in the orthoimagery (fig. 3). The mean offset (residual) was -0.14 m in the X-direction and -0.02 m in the Y-direction, with a standard deviation of 0.29 (0.20, Y-direction) and a root-mean-square error (RMSE) of 0.31 (0.27, Y-direction). No horizontal transformation was applied because horizontal offsets were not identified at or above the pixel scale (i.e., 0.21 m GSD). See accompanying report for additional detail.
Vertical accuracies of the DSM were evaluated by comparing the elevation values of ten checkpoints to the elevation values at the same location in the DSM. The mean vertical offset was -0.09 m with a standard deviation of 0.24 m and an RMSE of 0.25 (Table 1 of the accompanying report).
This data release is complete.
The aerial photography survey was planned so flight lines and photograph frequency provided 60 percent side lap and 80 percent end lap coverage, with an average above-ground-level flying height of 1341 m, resulting in 872 photos with 0.21 m ground sample distance (GSD). Ground-based GNSS surveys of stable, photo-identifiable ground control points (GCPs) and check points were conducted by DGGS scientists between fall 2014 and fall 2015 utilizing identical GNSS Topcon HiPer II rover and base units.
Are there legal restrictions on access or use of the data?
- Access_Constraints:
- This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
- Use_Constraints:
- Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
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RDF 2017-6
The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.
| Data format: | imagery |
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| Network links: |
<http://doi.org/10.14509/29736> |
(907)451-5039 (voice)
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