Identification_Information: Citation: Citation_Information: Originator: Wolken, G.J. Originator: Wikstroem Jones, Katreen Publication_Date: 2019 Title: Photogrammetry-derived digital surface model and orthoimagery of areas near the Dalton Highway, Yukon River Crossing, Alaska Geospatial_Data_Presentation_Form: orthoimage Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2019-4 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 5 p. Online_Linkage: http://doi.org/10.14509/30183 Description: Abstract: The 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). The orthoimagery is a four-band, 16-bit unsigned GeoTIFF file. The orthoimagery has a GSD of 0.24 m per pixel, and the "No Data" value is set to 256. Variable sky conditions during the photogrammetry survey resulted in some illumination anomalies in the southern part of the study area. Purpose: The 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. Supplemental_Information: >orthoimage: The orthoimagery is a four-band, 16-bit unsigned GeoTIFF file. The orthoimagery has a GSD of 0.24 m per pixel, and the "No Data" value is set to 256. Variable sky conditions during the photogrammetry survey resulted in some illumination anomalies in the southern part of the study area. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2016 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -150.018114 East_Bounding_Coordinate: -149.498806 North_Bounding_Coordinate: 65.940669 South_Bounding_Coordinate: 65.816791 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Theme_Keyword: Aerial Theme_Keyword: Aerial Photography Theme_Keyword: Coastal and River Theme_Keyword: Digital Surface Model (DSM) Theme_Keyword: Earthquake Related Slope Failure Theme_Keyword: Engineering Theme_Keyword: Engineering Geology Theme_Keyword: Environmental Theme_Keyword: Fracturing Theme_Keyword: Geologic Theme_Keyword: Geologic Hazards Theme_Keyword: Geological Process Theme_Keyword: Geology Theme_Keyword: Geomorphology Theme_Keyword: Geotechnical Theme_Keyword: Hazards Theme_Keyword: Landslide Theme_Keyword: Methods Theme_Keyword: Orthoimagery Theme_Keyword: Pipeline Theme_Keyword: Raster Image Theme_Keyword: Rockfall Theme_Keyword: Slides Theme_Keyword: Slope Theme_Keyword: Slope Instability Theme_Keyword: Structure From Motion Theme_Keyword: Surface Theme_Keyword: Surface Water Theme_Keyword: Surficial Theme_Keyword: Surficial Geology Theme_Keyword: Topography Theme_Keyword: Vegetation Theme_Keyword: Water Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Big Salt River Place_Keyword: Melozitna Mining District Place_Keyword: Rampart Mining District Place_Keyword: Ray River Place_Keyword: Sightas Island Place_Keyword: Smoothface Mountain Place_Keyword: Tolovana Mining District Place_Keyword: Trans-Alaska Pipeline Place_Keyword: Woodcamp Creek Place_Keyword: Yukon River 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Data_Set_Credit: These 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. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The 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. Logical_Consistency_Report: To 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. Completeness_Report: 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. This data release is complete. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The 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. > Check Point,Horizontal Offset X (m),Horizontal Offset Y (m),Easting (X),Northing (Y),Elevation (m) > YK-01,0.64,-1.16,385213.56,7303075.69,571.24 > YK-03,0.29,0.74,376208.41,7309124.78,95.28 > YK-04,-0.66,0.53,370524.83,7315054.63,160.34 > YK-05,0.69,-0.22,371052.7,7314408.97,152.61 > YK-06,-0.12,-0.11,374073.81,7311526.54,105.19 > YK-07,0.84,0,375527.33,7310228.21,96.83 > Mean,0.28,-0.04 > Std. Dev,0.58,0.67 > Range,1.5,1.9 > MAE,0.54,0.46 Lineage: Process_Step: Process_Description: Data 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. Process_Date: 2016 Process_Step: Process_Description: GNSS 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. Process_Date: 2016 Process_Step: Process_Description: Photogrammetry - 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. Process_Date: 2016 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: raster Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 6 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999600 Longitude_of_Central_Meridian: -147 Latitude_of_Projection_Origin: 0 False_Easting: 500000.000000 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: .00000001 Ordinate_Resolution: .00000001 Planar_Distance_Units: Meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: GRS 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257222101000025 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Attribute_Layer_Name: orthoimage Entity_Type_Label: orthoimage Entity_Type_Definition: The orthoimagery is a four-band, 16-bit unsigned GeoTIFF file. The orthoimagery has a GSD of 0.24 m per pixel, and the "No Data" value is set to 256. Variable sky conditions during the photogrammetry survey resulted in some illumination anomalies in the southern part of the study area. File format: GeoTIFF. Entity_Type_Definition_Source: Alaska Division of Geological & Geophysical Surveys (DGGS) Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Resource_Description: RDF 2019-4 Distribution_Liability: 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. Standard_Order_Process: Non-digital_Form: 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. Fees: Contact DGGS for current pricing Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: orthoimage Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://doi.org/10.14509/30183 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20190806 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Person: Simone Montayne Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Use_Constraints: If 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. Metadata_Extensions: Online_Linkage: http://www.dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions