{"action":"create","ckan_id":null,"date_created":"Wed, 01 Apr 2026 06:32:09 GMT","date_finished":null,"harvest_job_id":"467783bb-b8d0-4c39-87c0-5c3b6e014eea","harvest_source_id":"f4c7bbab-c7ef-4277-a7d3-c25b78854814","id":"dcf891f6-aeda-4b0c-9c93-2ff4debc366a","identifier":"https://dggs.alaska.gov/webpubs/metadata/RDF2019-4-dsm.xml","parent_identifier":null,"source_hash":"e9cae17c0ac9995fb70ad1fb0cafe21b7295e26aafb48b6907f0e263900035a3","source_raw":"\n\n\n\n\nWolken, G.J.\nWikstroem Jones, Katreen\n2019\nPhotogrammetry-derived digital surface model and orthoimagery of areas near the Dalton Highway, Yukon River Crossing, Alaska\ndigital surface model\n\nRaw Data File\nRDF 2019-4\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n5 p.\nhttp://doi.org/10.14509/30183\n\n\n\nThe State of Alaska Division of Geological & Geophysical Surveys (DGGS) produced a digital surface model (DSM) and an orthorectified aerial image (orthoimagery) over Yukon River Crossing in support of landslide hazard mapping. Aerial photographs and Global Navigation Satellite System (GNSS) data were collected on June 30, 2016, and were processed using Structure-from-Motion (SfM) photogrammetric techniques to create the DSM and orthoimagery. For the purpose of enabling open access to geospatial datasets in Alaska, this collection is being released as a Raw Data File with an open end-user license. All files can be downloaded free of charge from the DGGS website (http://doi.org/10.14509/30183). DSMs represent surface elevations of all surfaces, including vegetation, vegetation-free land, bridges, buildings, etc. The Yukon River (not including tributaries and lakes within the study area) was hydro flattened using standardized hydro flattening workflow in ArcMap (McLean, 2018) with a resulting elevation change from 85.1 m in the east to 81.1 m in the west within the DSM boundary (east-west streamflow direction). The DSM is a single-band, 32-bit float GeoTIFF file, with a ground sample distance (GSD) of 0.47 m. No Data value is set to -3.40282306074e+038.\nThe data release is one of a series of Alaska Division of Geological & Geophysical Surveys (DGGS) publications to present elevation data over Yukon River Crossing in support of landslide hazard mapping.\n>digital surface model: DSMs represent surface elevations of all surfaces, including vegetation, vegetation-free land, bridges, buildings, etc. The Yukon River (not including tributaries and lakes within the study area) was hydro flattened using standardized hydro flattening workflow in ArcMap (McLean, 2018) with a resulting elevation change from 85.1 m in the east to 81.1 m in the west within the DSM boundary (east-west streamflow direction). The DSM is a single-band, 32-bit float GeoTIFF file, with a ground sample distance (GSD) of 0.47 m. No Data value is set to -3.40282306074e+038.\n\n\n\n\n2016\n\n\nground condition\n\n\ncomplete\nNone planned\n\n\n\n-150.018114\n-149.498806\n65.940669\n65.816791\n\n\n\n\nISO 19115 Topic Category\ngeoscientificInformation\n\n\nAlaska Division of Geological & Geophysical Surveys\nAerial\nAerial Photography\nCoastal and River\nDigital Surface Model (DSM)\nEarthquake Related Slope Failure\nEngineering\nEngineering Geology\nEnvironmental\nFracturing\nGeologic\nGeologic Hazards\nGeological Process\nGeology\nGeomorphology\nGeotechnical\nHazards\nLandslide\nMethods\nOrthoimagery\nPipeline\nRaster Image\nRockfall\nSlides\nSlope\nSlope Instability\nStructure From Motion\nSurface\nSurface Water\nSurficial\nSurficial Geology\nTopography\nVegetation\nWater\n\n\nAlaska Division of Geological & Geophysical Surveys\nBig Salt River\nMelozitna Mining District\nRampart Mining District\nRay River\nSightas Island\nSmoothface Mountain\nTolovana Mining District\nTrans-Alaska Pipeline\nWoodcamp Creek\nYukon River\n\n\nThis 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).\nAny 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.\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nMetadata Manager\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nThese data products were funded by the Alaska Department of Transportation & Public Facilities, and Alaska Department of Natural Resources, Division of Geological & Geophysical Surveys. We thank Clearwater Air for their aviation expertise and contribution to these data products.\n\n\n\nThe DSM and orthoimagery have been visually inspected for data errors such as pits, border artifacts, and shifting. The end-user should be aware that pits and peaks are present in areas of some small water bodies, such as lakes and ponds, and that DSM data have not been hydro-flattened in these areas.\n\nTo evaluate data consistency, ground control checkpoints were collected (September 21, 2016) as rapid-static occupations (15 min) with a Trimble R8 GNSS receiver. A Trimble R7 GNSS receiver with Zephyr-2 antenna was deployed near the center of the study area and was used as horizontal and vertical control for checkpoint baseline corrections.\nThe aerial photographic survey resulted in approximately 60 percent side lap and 80 percent end lap coverage, with an above ground-level flying height of 1,100-2,000 m, which resulted in 4,922 photos with 0.24 m ground sample distance (GSD). The total area surveyed was approximately 360 km2. This data release is complete.\n\n\n\nThe horizontal accuracy was assessed by comparing the locations of six GNSS-derived control points with their locations in the orthoimagery. The initial mean offset (residual) was +1.35 m in the X-direction and -0.03 m in the Y-direction, with a standard deviation of 0.47 m (0.65 m, Y-direction) and a mean-absolute-error (MAE) of 1.35 m (0.46 m, Y-direction). A horizontal transformation of -1.35 m in X-direction was applied because horizontal offset was identified above the pixel scale of the DEM (i.e., 0.47 m GSD). The final horizontal accuracies were based on the same control points as checkpoints and are described in table 1 of the accompanying report. \n\t\t\t\t\t>\tCheck Point,Horizontal Offset X (m),Horizontal Offset Y (m),Easting (X),Northing (Y),Elevation (m)\n\t\t\t\t\t> \tYK-01,0.64,-1.16,385213.56,7303075.69,571.24\n\t\t\t\t\t> \tYK-03,0.29,0.74,376208.41,7309124.78,95.28\n\t\t\t\t\t>\tYK-04,-0.66,0.53,370524.83,7315054.63,160.34\n\t\t\t\t\t>\tYK-05,0.69,-0.22,371052.7,7314408.97,152.61\n\t\t\t\t\t>\tYK-06,-0.12,-0.11,374073.81,7311526.54,105.19\n\t\t\t\t\t>\tYK-07,0.84,0,375527.33,7310228.21,96.83\n\t\t\t\t\t>\tMean,0.28,-0.04\n\t\t\t\t\t>\tStd. Dev,0.58,0.67\n\t\t\t\t\t>\tRange,1.5,1.9\n\t\t\t\t\t>\tMAE,0.54,0.46\n\n\n\nThe DSM was vertically controlled by comparing the elevation values of 9,794 points collected in transects along the highway on a paved surface in the photogrammetry-derived DSM to the elevation values at the same location in a lidar-derived dataset (bare earth DEM) collected in May 2011 (Hubbard and others, 2011). The initial mean vertical offset was -1.60 m with a standard deviation of 0.38 and Root-Mean-Square-Error of 1.64 m. A vertical transformation of +1.60 m was applied. The final DSM vertical accuracy was evaluated with an additional 10,469 checkpoints and has a mean vertical residual of 0.02 m with a standard deviation of 0.41 m and an RMSE of 0.41 m.\n\n\n\n\nData acquisition - DGGS collected digital aerial photographic data on June 30, 2016, using a fixed-wing (Cessna 180) airborne platform. The aerial photographic survey resulted in approximately 60 percent side lap and 80 percent end lap coverage, with an above ground-level flying height of 1,100-2,000 m, which resulted in 4,922 photos with 0.24 m ground sample distance (GSD). The total area surveyed was approximately 360 km2. A Nikon D800 with an AF-Nikkor 24mm f/5D lens was used to collect 36.2-megapixel JPEG photographs (7,360 x 4,912 pixels per image) which were compressed for optimal quality. The aerial photographic survey was controlled with an Aerometric flight control system and Aviatrix software that linked the camera shutter release with Global Navigation Satellite System (GNSS) event markers created by an onboard Trimble R7 receiver and a dual-band Novatel roof-mounted antenna mounted 0.96 m above the camera. On September 21, 2016 checkpoints were collected as rapid-static occupations (15 min) with a Trimble R8 GNSS receiver. A Trimble R7 GNSS receiver with Zephyr-2 antenna was deployed near the center of the study area and was used as horizontal and vertical control for checkpoint baseline corrections.\n2016\n\n\nGNSS data processing - Aerial survey GNSS data (camera coordinates and trajectory data) were processed using GrafNav GNSS post-processing software, using Precise Point Positioning (PPP) methods. Nearby Continuously Operating Reference Stations (CORS) were used as the vertical and horizontal control for this process. GNSS data were collected and processed in WGS84 (G1674) using the WGS84 ellipsoid. Camera coordinates were converted to the North American Datum 1983 (NAD83, 2011) European Petroleum Survey Group Well Known Identification Number (EPSG) 6335 and the North American Vertical Datum of 1988 (NAVD88; Geoid12A; EPOCH 2010.00) using the National Geodetic Survey (NGS) VDatum tool (NOAA, 2018). The coordinates are projected in UTM Zone 6 North and are in meters. The converted camera coordinates were manually correlated to image filenames to create a camera exterior orientation file for import into the photogrammetric software, Agisoft Photoscan Professional. The exterior orientation file provides the X, Y, and Z position for each photograph taken during the survey. Yaw, pitch, and roll information were not recorded during the flight. The Trimble R7 Zephyr-2 base station position was corrected using the NGS Online Positioning User Service (OPUS) with the IGS08 (EPOCH 2015.6162). Checkpoint GNSS data were differentially corrected with the OPUS-corrected base station coordinates using GrafNet GNSS static network processing software.\n2016\n\n\nPhotogrammetry - Aerial stereo-photographs were imported into the commercially available Agisoft Photoscan Professional software (Version 1.2.3 build 2331). Photos were processed in Photoscan on a Windows PC to align aerial photos, edit the sparse point cloud, optimize the bundle block adjustment, construct the dense point cloud and triangulated irregular network geometry, and export the natural color (RGB) orthoimagery GeoTIFF.\n2016\n\n\n\n\nraster\n\n\n\n\n\nUniversal Transverse Mercator\n\n6\n\n0.999600\n-147\n0\n500000.000000\n0\n\n\n\n\ncoordinate pair\n\n.00000001\n.00000001\n\nMeters\n\n\n\nNorth American Datum of 1983\nGRS 80\n6378137\n298.257222101000025\n\n\n\n\n\n\ndigital surface model\nDSMs represent surface elevations of all surfaces, including vegetation, vegetation-free land, bridges, buildings, etc. The Yukon River (not including tributaries and lakes within the study area) was hydro flattened using standardized hydro flattening workflow in ArcMap (McLean, 2018) with a resulting elevation change from 85.1 m in the east to 81.1 m in the west within the DSM boundary (east-west streamflow direction). The DSM is a single-band, 32-bit float GeoTIFF file, with a ground sample distance (GSD) of 0.47 m. No Data value is set to -3.40282306074e+038. File format: GeoTIFF.\nAlaska Division of Geological & Geophysical Surveys (DGGS)\ndigital surface model\n\n\n\n\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nMetadata Manager\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nRDF 2019-4\nThe 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.\n\nDGGS 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.\nContact DGGS for current pricing\n\n\n\n\ndigital surface model\n\n\n\n\n\nhttp://doi.org/10.14509/30183\n\n\n\n\n\nFree download\n\n\n\n20190806\n\n\n\nAlaska Division of Geological & Geophysical Surveys\nSimone Montayne\n\nMetadata Manager\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nFGDC Content Standard for Digital Geospatial Metadata\nFGDC-STD-001-1998\nIf the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys.\n\nhttp://www.dggs.alaska.gov/metadata/dggs.ext\ndggs metadata extensions\n\n\n\n","source_transform":null,"status":"error"}