{"action":"create","ckan_id":null,"date_created":"Wed, 08 Apr 2026 06:53:42 GMT","date_finished":null,"harvest_job_id":"abb06220-7a4b-40a2-ac1f-706b64ae3bfc","harvest_source_id":"f4c7bbab-c7ef-4277-a7d3-c25b78854814","id":"f4c9d979-a255-4bfd-9ba8-b8c9c88223b1","identifier":"https://dggs.alaska.gov/webpubs/metadata/RDF2018-2-orthoimage.xml","parent_identifier":null,"source_hash":"351ac097e7706f4a1b56e24afebd7492bd4ab3756f61fb9f19917ec2dec12ec1","source_raw":"\n\n\n\n\nBalazs, M.S.\nWolken, G.J.\nWikstrom Jones, Katreen\n2018\nPhotogrammetry-derived digital surface model and orthoimagery of land areas near Resurrection Bay, Alaska\northoimage\n\nRaw Data File\nRDF 2018-2\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n6 p.\nhttp://doi.org/10.14509/29824\n\n\n\nThe State of Alaska Division of Geological & Geophysical Surveys (DGGS) produced a digital surface model (DSM) and an orthorectified aerial optical image mosaic (orthoimagery) of the Resurrection Bay watershed, surrounding the city of Seward in south-central Alaska. Aerial photographs and Global Navigation Satellite System (GNSS) data were collected on August 13, 2015, and were processed using Structure-from-Motion (SfM) photogrammetric techniques to create the DSM and orthoimagery. All data are projected in UTM Zone 6 North (meters) using the NAD83 (2011; EPSG 26906) horizontal datum and NAVD88 (Geoid12A; EPOCH 2010.00) vertical datum. The project was part of an ongoing investigation of the impact of flooding, slope instability, and cryosphere hazards on infrastructure and public safety. 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/10.14509/29824). The orthoimage is a three-band, 8-bit unsigned GeoTIFF file using LZW compression. The orthoimage has a GSD of 0.2 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.\nThe orthoimage is a three-band, 8-bit unsigned GeoTIFF file using LZW compression. The orthoimage has a GSD of 0.2 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. This file was created for ongoing investigation of the impact of flooding, slope instability, and cryosphere hazards on infrastructure and public safety in the the Resurrection Bay watershed. Data were collected on August 13, 2015.\n>orthoimage: The orthoimage is a three-band, 8-bit unsigned GeoTIFF file using LZW compression. The orthoimage has a GSD of 0.2 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.\n\n\n\n\n2015\n\n\nground condition\n\n\ncomplete\nNone planned\n\n\n\n-149.598135\n-149.184355\n60.234358\n59.970362\n\n\n\n\nISO 19115 Topic Category\ngeoscientificInformation\n\n\nAlaska Division of Geological & Geophysical Surveys\nAerial\nEngineering\nEngineering Geology\nEnvironmental\nGeologic\nGeologic Hazards\nGeological Process\nGeology\nGeomorphology\nHazards\nLakes\nMethods\nOrthoimagery\nRaster Image\nSlope\nSurface\nSurficial\nSurficial Geology\nVegetation\nWater\n\n\nAlaska Division of Geological & Geophysical Surveys\nBear Creek\nBear Lake\nBear Lake Glacier\nBear Mountain\nBox Canyon Creek\nCaines Head\nCallisto Peak\nClear Creek\nDerby Cove\nFirst Lake\nFourth of July Creek\nGodwin Creek\nGrouse Lake\nJapanese Creek\nLikes Creek\nLittle Bear Lake\nLost Creek\nLost Lake Trail\nLowell Creek\nLowell Point\nMarathon Mountain\nMount Alice\nMount Benson\nMount Eva\nPhoenix Peak\nPreachers Pond\nProspect Glacier\nRace Point\nResurrection Bay\nResurrection River\nSalmon Creek\nSawmill Creek\nScheffler Creek\nSecond Lake\nSeward\nSpring Creek\nSpruce Creek\nThe Lagoon\nThumb Cove\nTiehacker Mountain\nTonsina Creek\nTonsina Point\nWoodrow\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\nThis project is funded by Seward Bear Creek Flood Service Area, Kenai Peninsula Borough, DGGS through a State of Alaska Capital Improvement Project, and the University of Alaska Fairbanks, Geophysical Institute.\n\n\n\nThe DSM a ground sample distance (GSD) of 0.41 m, and the No Data value is set to -32767. The orthoimage has a GSD of 0.2 m per pixel, and the No Data value is set to 0. The DSM and orthoimagery have been visually inspected for data errors such as pits, border artifacts, and shifting. Pits and peaks are present over water bodies such as lakes. The end-user should be aware that DSM data were not hydro-flattened. Some small areas along the boundary and northern region of the survey area have NO DATA values, which is due to insufficient overlap (gaps) in the aerial photographic survey in areas of extreme topographic relief. The end user is advised that such areas may have a less accurate geographic position than reported for the rest of the scene.\n\nThe aerial photography survey used a fixed-wing airborne platform and was planned so flight lines and photograph frequency provided 60 percent side lap and 80 percent end lap coverage, with an average above-sea-level flying height of 1260 m. The aerial photography survey covered 383 km2, resulting in 4021 photos with 0.2 m ground sample distance (GSD). Nineteen photo-identifiable checkpoints were collected by University of Alaska Fairbanks, Geophysical Institute personnel in September 2015 using two Trimble R8s GPS receivers. Checkpoint locations and offsets are provided in the accompanying report.\nThis data release is complete.\n\n\nHorizontal accuracies of the orthoimagery and DSM were assessed using 19 photo-identifiable checkpoints along the road systems in and near Seward, Alaska. Lower horizontal accuracy is possible in areas of extreme terrain, dense vegetation, and heavy shadow. The X-coordinates have a root-mean-square error (RMSE) of 0.32m and a mean absolute error (MAE) of 0.28 m. The Y Coordinates have an RMSE of 0.47 m and a MAE of 0.42 m. The horizontal linear RMSE in the radial direction (RMSEr) is 0.57 m. See accompanying report for additional detail.\n\n\n\n\nData acquisition - The State of Alaska Division of Geological & Geophysical Surveys contracted the collection of digital aerial photographic data on August 13, 2015. The aerial photography survey used a fixed-wing airborne platform and was planned so flight lines and photograph frequency provided 60 percent side lap and 80 percent end lap coverage, with an average above-sea-level flying height of 1260 m. The aerial photography survey covered 383 km2, resulting in 4021 photos with 0.2 m ground sample distance (GSD). A Nikon D800 camera with AF-Nikkor 28mm f/2.8D lens was used to collect 36.2-megapixel JPEG photographs (7360 x 4912 pixels per image) which were compressed for optimal quality. During the aerial survey, the photograph coordinates were determined using an OxTS GPS-IMU system and a Cirrus Digital Systems intervalometer that linked the camera shutter release to the GPS-IMU. The camera was mounted inside the aircraft with the GPS antenna positioned over the camera. The GPS antenna offset (X=0.3, Y=0.0, Z=0.94) was corrected during GPS post-processing to solve for the camera coordinates. A Trimble 5700 GPS receiver with a Trimble Zephyr 4-point feed antenna was deployed approximately 160 meters north of the northeast corner of the Seward Airport and was used as the GPS base station for horizontal and vertical control during the aerial survey. Nineteen photo-identifiable checkpoints were collected by University of Alaska Fairbanks, Geophysical Institute personnel in September 2015 using two Trimble R8s GPS receivers (fig. 2). The base station was located on National Geodetic Survey benchmark X-74 (PID: TT0396), located west of the Seward Airport.\n2015\n\n\nGNSS data processing - Aerial survey GPS data were processed using GrafNav GNSS Post-Processing Software, Version 8.40.5121 using post-processing kinematic (PPK) methods. The Trimble Zephyr base station position was corrected using the National Geodetic Survey OPUS with the IGS08 (EPOCH:2015.6162) solution. Both aerial and base GPS data were collected and processed in WGS84 (G1674) using the WGS84 ellipsoid. Standard deviations for the GPS event marker horizontal and vertical positions were less than 0.06 m. After post-processing, GPS event marker coordinates needed to be converted to the datum most frequently used by DGGS stakeholders. We used the National Oceanic and Atmospheric Administration's VDatum tool to transform the GPS event marker coordinates to the North American Datum 1983 (NAD83; 2011) European Petroleum Survey Group Well Known Identification Number (EPSG) 6337 and the North American Vertical Datum of 1988 (NAVD88; Geoid12A; EPOCH 2010.00). The coordinates are projected in UTM Zone 6 North and are in meters. GPS event marker coordinates were manually correlated to image filenames to create a camera exterior orientation file for import into the SfM software, Agisoft Photoscan Professional. The exterior orientation file provides the X, Y, Z positions and Yaw, pitch, and roll for each photograph taken during the survey.\n2015\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.\n2015\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\northoimage\nThe orthoimage is a three-band, 8-bit unsigned GeoTIFF file using LZW compression. The orthoimage has a GSD of 0.2 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. File format: GeoTIFF.\nAlaska Division of Geological & Geophysical Surveys (DGGS) and Fairbanks Airborne Remote Sensing\northoimage\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 2018-2\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\northoimage\n\n\n\n\n\nhttp://doi.org/10.14509/29824\n\n\n\n\n\nFree download\n\n\n\n20180112\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"}