digital surface model: DSMs represent elevations of all surfaces, including vegetation, vegetation-free land, bridges, buildings, etc. The DSM is a single-band, 32-bit float GeoTIFF file, with a GSD of 2.5 cm. The "No Data" value is set to -9999. orthoimage: The orthoimage is a four-band, 16-bit unsigned GeoTIFF file, with a GSD of 2.5 cm. The "No Data" value is set to 256.
Herriott, T.M., Wikstrom Jones, Katreen, Wolken, G.J., and Willingham, A.L., 2020, Photogrammetry-derived digital surface model and orthoimagery of the Usibelli Group type section, Suntrana Creek, Alaska: Raw Data File RDF 2020-2, 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.
The State of Alaska funded this work. We thank helicopter pilot Alex Shapiro (Alaska Land Exploration) for precise flying during the Suntrana Creek photogrammetric survey. Michelle Gavel assisted with image masking. Discussions with Marwan Wartes and Dave LePain regarding the Usibelli Group stratigraphy are much appreciated. Additional support in data handling and digital products was provided by Andrew Herbst, Mike Hendricks, Kristen Janssen, and Simone Montayne.
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The goal of this data release is to provide a visual and quantitative context for the stratigraphy Cenozoic Usibelli Group in support of geologic and and economic studies.
Wartes, M.A., Gillis, R.J., Herriott, T.M., Stanley, R.G., Helmold, K.P., Peterson, C.S., and Benowitz, J.A., 2013, Summary of 2012 reconnaissance field studies related to the petroleum geology of the Nenana basin, interior Alaska: Preliminary Interpretive Report PIR 2013-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
The DSM and orthoimagery were visually inspected for data errors such as pits, border artifacts, and shifting.
Fourteen GNSS points were collected as real-time kinematic occupations with a Trimble R8 GNSS receiver; 10 of these points were employed as ground control points and four were designated as checkpoints. A Trimble R7 GNSS receiver with Zephyr-2 antenna was deployed as a base station near the road at the mouth of Suntrana Creek and used as horizontal and vertical control for real-time kinematic baseline adjustments. The Trimble R7 Zephyr-2 base station position was corrected using the NGS Online Positioning User Service (OPUS) with the IGS08 (EPOCH:2018.3559). Real-time kinematic baselines of ground control points and checkpoints were differentially adjusted with the corrected base station coordinates using Trimble Business Center processing software. Four of the GCPs were designated as checkpoints to assess horizontal accuracy of the data products by comparing these four GNSS-derived points with their locations on the orthoimage. The mean offsets (residual) are -0.0190 m in the X-direction and 0.0197 m in the Y-direction, with standard deviations of 0.0311 m (X-direction) and 0.0512 m (Y-direction) and mean absolute errors of 0.0275 m (X-direction) and 0.0379 m (Y-direction). No horizontal transformation is applied because the horizontal mean offsets are less than the DSM's scale of 2.5 cm per pixel. A table of checkpoints and errors is provided in the accompanying report.
Vertical accuracy of the DSM is evaluated by comparing the elevation values of the same four checkpoints in the photogrammetry-derived DSM to the GNSS-derived elevation values. The mean vertical offset (Z-direction) is -0.0209 m, with a standard deviation of 0.0379 and mean absolute error of 0.0320 cm (table 1). No vertical transformation is applied. A table of checkpoints and errors is provided in the accompanying report.
The design ground sample distance (GSD) is 1.8 cm. Each photograph is 45.4-megapixels (8256 x 5504 pixels); images were recorded in a 14-bit, losslessly compressed NEF (RAW) file format. Twenty-one north-south-trending, near-nadir-view flight lines were flown with approximately 60 percent side-lap (that is to say, frame overlap between adjacent flight lines); sequential frames were collected to yield at least 75 percent end-lap. Two additional east-west-trending, near-nadir-view flight lines, as well as two oblique-view flight lines of the Suntrana Creek valley walls, were also flown, further bolstering the photographic dataset and ensuring convergent imagery geometries in a critical part of the survey area. The dataset ultimately comprised 568 photographs (see below), and the total area surveyed is approximately 1 km2.This data release is complete.
A Trimble R7 GNSS receiver with Zephyr-2 antenna was deployed as a base station near the road at the mouth of Suntrana Creek and used as horizontal and vertical control for real-time kinematic baseline adjustments. The Trimble R7 Zephyr-2 base station position was corrected using the NGS Online Positioning User Service (OPUS) with the IGS08 (EPOCH:2018.3559). Real-time kinematic baselines of ground control points and checkpoints were differentially adjusted with the corrected base station coordinates using Trimble Business Center processing software. Four of the GCPs were designated as checkpoints to assess horizontal accuracy of the data products by comparing these four GNSS-derived points with their locations on the orthoimage.
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 2020-2
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/10.14509/30425> |
(907)451-5020 (voice)
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