Identification_Information: Citation: Citation_Information: Originator: Wikstrom Jones, K.M. Originator: Wolken, G.J. Originator: Daanen, R.P. Publication_Date: 2026 Title: Lidar-derived elevation data for Barry Arm landslide, southcentral Alaska, October 16, 2020 Geospatial_Data_Presentation_Form: data Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2026-5 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 9 p. Online_Linkage: https://doi.org/10.14509/31970 Description: Abstract: Lidar-derived elevation data for Barry Arm landslide, southcentral Alaska, October 16, 2020, Raw Data File 2026-5, provides classified point cloud, a digital terrain model (DTM), a surface model (DSM), and an intensity model for the Barry Arm landslide, northeast of Whittier in Prince William Sound in southcentral Alaska, during near-snow-free ground conditions. The goal of the survey is to provide snow-free surface elevation data to assess landslide movement using repeat surveys during snow-free conditions. Airborne data were collected on October 16, 2020, and subsequently processed in Terrasolid and ArcGIS. Ground control was also collected on October 16, 2020. These data are provided as a Raw Data File under an open end-user license and are available on the DGGS website (http://doi.org/10.14509/31970). Purpose: These elevation data products were generated to support assessment of landslide movement at the Barry Arm site. Accurate, snow‑free elevation measurements allow scientists to detect subtle changes in the terrain over time. Monitoring these changes helps identify accelerating movement, evaluate potential slope instability, and improve understanding of the landslide's behavior. This information is essential for assessing hazards, informing risk‑mitigation efforts, and supporting decision‑making for communities and infrastructure that could be affected by rapid slope failure or tsunami generation in Barry Arm. Supplemental_Information: >boundaries: A boundary, also known as an Area of Interest (AOI) or border, that defines the area covered by the data. >classified_points: Classified point cloud data are provided in LAZ format. Classification follows ASPRS 2025 standards with return and intensity values. Ground-classified points have a mean density of 41.1 pts/m2 and an average spacing of 15.6 cm. >dsm: The DSM represents surface elevations, including heights of vegetation and structures. The DSM is a single-band, 32-bit tiled GeoTIFF dataset of 10-cm resolution. No Data value is set to -3.40282306074e+38 (32-bit, floating-point minimum). >dtm: The DTM represents bare earth elevations, excluding vegetation and structures. The DTM is a single-band, 32-bit tiled GeoTIFF dataset of 10-cm resolution. No Data value is set to -3.40282306074e+38. >footprints: Footprints for tiled data. >lidar_intensity: The lidar intensity image describes the relative amplitude of reflected signals contributing to the point cloud. Lidar intensity is (1) primarily a function of scanned object reflectance in relation to the signal frequency, (2) dependent on ambient conditions, and (3) not necessarily consistent between separate scans. The intensity image is a single-band, 32-bit GeoTIFF file of 1-m resolution, with a No Data value set to -3.40282306074e+38. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20201016 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -148.183029 East_Bounding_Coordinate: -148.099108 North_Bounding_Coordinate: 61.187321 South_Bounding_Coordinate: 61.121755 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 Geology Theme_Keyword: Debris Avalanche Theme_Keyword: Debris Flow Theme_Keyword: DGGS Theme_Keyword: Digital Elevation Model Theme_Keyword: Digital Surface Model (DSM) Theme_Keyword: Digital Terrain Model Theme_Keyword: Elevation Theme_Keyword: Engineering Theme_Keyword: Engineering Geology Theme_Keyword: Geologic Theme_Keyword: Geologic Hazards Theme_Keyword: Geological Process Theme_Keyword: Geology Theme_Keyword: Geomorphology Theme_Keyword: Geotechnical Theme_Keyword: Glacial Theme_Keyword: Glacial Deposits Theme_Keyword: Glacial Geology Theme_Keyword: Glacial Geomorphology Theme_Keyword: Glacial Processes Theme_Keyword: Hazards Theme_Keyword: Landslide Theme_Keyword: Landslide Susceptibility Theme_Keyword: LAS Index Shapefile Theme_Keyword: LiDAR Theme_Keyword: LiDAR Intensity Image Theme_Keyword: LiDAR LAS File Format Theme_Keyword: Point Cloud Data Theme_Keyword: Remote Sensing Theme_Keyword: Rock Avalanche Theme_Keyword: Rockfall Theme_Keyword: Slope Theme_Keyword: Slope Instability Theme_Keyword: Surface Theme_Keyword: Surficial Theme_Keyword: Surficial Geology Theme_Keyword: Topography Theme_Keyword: Unconsolidated Deposits Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Barry Arm Place_Keyword: Barry Glacier Place_Keyword: Cascade Glacier Place_Keyword: Southcentral Alaska 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 Contact_Instructions: Please view our website (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible. Data_Set_Credit: These data products were funded by the State of Alaska Landslide Hazard Capital Improvement Project and collected and processed by DGGS. We thank Clearwater Air and Alpine Air for their aviation expertise and contribution to these data products. Cross_Reference: Citation_Information: Originator: Daanen, R.P. Originator: Wolken, G.J. Originator: Wikstrom Jones, K.M. Originator: Herbst, A.M. Publication_Date: 2021 Title: High resolution lidar-derived elevation data for Barry Arm landslide, southcentral Alaska, June 26, 2020 Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2021-3 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 9 p Online_Linkage: https://doi.org/10.14509/30593 Cross_Reference: Citation_Information: Originator: Daanen, R.P. Originator: Wolken, G.J. Originator: Wikstrom Jones, K.M. Originator: Herbst, A.M. Publication_Date: 2021 Title: Lidar-derived elevation data for upper Barry Arm, southcentral Alaska, June 26, 2020 Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2021-1 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 9 p Online_Linkage: https://doi.org/10.14509/30589 Cross_Reference: Citation_Information: Originator: Wikstrom Jones, K.M. Originator: Wolken, G.J. Originator: Daanen, R.P. Originator: Herbst, A.M. Publication_Date: 2021 Title: Photogrammetry-derived orthoimagery and elevation data for Barry Arm landslide, southcentral Alaska, June 27, 2020 Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2021-5 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 6 p Online_Linkage: https://doi.org/10.14509/30596 Cross_Reference: Citation_Information: Originator: Zechmann, J.M. Originator: Wolken, G.J. Originator: Wikstrom Jones, K.M. Publication_Date: 2025 Title: Lidar-derived elevation data for Barry Arm, southcentral Alaska, collected September 19, 2023 Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-8 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 9 p Online_Linkage: https://doi.org/10.14509/31520 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Not applicable Logical_Consistency_Report: Data quality is consistent throughout the survey, save for gaps over bodies of water, glaciers, and snow-covered surfaces. Completeness_Report: This is a full-release dataset. There was no over-collect. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal accuracy was not measured for this collection; it is considered inherent in the airborne GPS/IMU solution. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: We measured a vertical mean offset of +77.2 cm between 54 control points and the point cloud. This offset was reduced to -3 cm by applying a constant vertical correction to the lidar point data. We used 15 checkpoints to determine the non-vegetated vertical accuracy (NVA) of the point cloud ground class, using a tin-based approach. Project NVA was calculated to have a root mean square error (RMSE) of 20 cm. Relative accuracy was evaluated based on interswath overlap consistency, yielding an RMSE of 2.3 cm. Lineage: Process_Step: Process_Description: Ground survey - Ground control and checkpoints were collected on October 16, 2020. A Trimble R10-2 GNSS receiver with an internal antenna was deployed near the center of the study area on the ridge. It provided a base station occupation and real-time kinematic (RTK) corrections to points surveyed with a rover Trimble R10-2 GNSS receiver (internal antenna). We collected 70 ground control and check points to use for calibration and to assess the vertical accuracy of the point cloud; 67 of these were used for this lidar acquisition. Checkpoints were collected on bare earth or minimally vegetated surface. Process_Date: 20201016 Process_Step: Process_Description: Aerial survey - DGGS used a Riegl VUX1-LR laser scanner with a global navigation satellite system (GNSS) and a Northrop Grumman LN-200C inertial measurement unit (IMU) integrated by Phoenix LiDAR Systems. The sensor can collect a maximum of 820,000 points per second at a range of 215 m, or a minimum of 50,000 points per second at 820 m (ranges assume greater than or equal to 20 percent natural reflectance). This survey was flown with a pulse refresh rate of 200,000 to 400,000 pulses per second and a scan rate of 80 to 150 lines per second. We used a Cessna 180 Skywagon fixed-wing platform to survey from an elevation of approximately 100-300 m above ground level, at a ground speed of approximately 40 m/s, and with a scan angle set from 80 to 280 degrees. The total area surveyed was approximately 12.6 km2. The airborne survey was flown on October 16, 2020, beginning at 9:35 am AKST and ending at 10:48 am AKST. The weather throughout the survey was fair and cloudless. Process_Date: 20201016 Process_Step: Process_Description: Dataset processing - We processed point data in SDCimport for initial filtering and multiple-time-around (MTA) disambiguation. MTA errors, corrected in this process, result from ambiguous interpretations of received pulse time intervals and occur more frequently with higher pulse refresh rates. IMU and GNSS data were processed in Inertial Explorer, and flightline information was integrated with the point cloud in Spatial Explorer. We calibrated the point data at an incrementally precise scale of sensor movement and behavior, incorporating sensor velocity, roll, pitch, and yaw fluctuations throughout the survey. For the lidar data collection, the pulse density is 41.3 pulses/m2, and the average pulse spacing is 15.6 cm. We created a macro (an ordered list of point classification commands tailored to this dataset) in Terrasolid software and classified points in accordance with the American Society for Photogrammetry & Remote Sensing (ASPRS) 2025 guidelines (ASPRS, 2025). After classification, we applied a geometric transformation to convert points from ellipsoidal heights to GEOID12B (Alaska) orthometric heights. Raster products were derived from the point cloud in ArcGIS Pro. A 20-cm DSM was interpolated from ground and vegetation classes using a triangulation method and maximum values. A 20-cm DTM was interpolated from all ground-class returns using triangulation method and minimum values. We also produced a 1-m intensity image for the area using average binning in ArcGIS Pro, with no normalization or corrections applied. Process_Date: 2025 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: NAD83 (2011) Ellipsoid_Name: GRS 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: NAVD88, GEOID12B Altitude_Resolution: 0.500000 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: boundaries Entity_Type_Definition: A boundary, also known as an Area of Interest (AOI) or border, that defines the area covered by the data. Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: boundaries Detailed_Description: Entity_Type: Entity_Type_Label: classified_points Entity_Type_Definition: Classified point cloud data are provided in LAZ format. Classification follows ASPRS 2025 standards with return and intensity values. Ground-classified points have a mean density of 41.1 pts/m2 and an average spacing of 15.6 cm. Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: classified_points Detailed_Description: Entity_Type: Entity_Type_Label: dsm Entity_Type_Definition: The DSM represents surface elevations, including heights of vegetation and structures. The DSM is a single-band, 32-bit tiled GeoTIFF dataset of 10-cm resolution. No Data value is set to -3.40282306074e+38 (32-bit, floating-point minimum). Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: dsm Detailed_Description: Entity_Type: Entity_Type_Label: dtm Entity_Type_Definition: The DTM represents bare earth elevations, excluding vegetation and structures. The DTM is a single-band, 32-bit tiled GeoTIFF dataset of 10-cm resolution. No Data value is set to -3.40282306074e+38. Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: dtm Detailed_Description: Entity_Type: Entity_Type_Label: footprints Entity_Type_Definition: Footprints for tiled data. Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: footprints Detailed_Description: Entity_Type: Entity_Type_Label: lidar_intensity Entity_Type_Definition: The lidar intensity image describes the relative amplitude of reflected signals contributing to the point cloud. Lidar intensity is (1) primarily a function of scanned object reflectance in relation to the signal frequency, (2) dependent on ambient conditions, and (3) not necessarily consistent between separate scans. The intensity image is a single-band, 32-bit GeoTIFF file of 1-m resolution, with a No Data value set to -3.40282306074e+38. Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: lidar_intensity 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 Contact_Instructions: Please view our website (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible. Resource_Description: RDF 2026-5 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: data Format_Version_Date: 20260130 Format_Information_Content: boundaries, classified points, dsm, dtm, footprints and lidar intensity Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.14509/31970 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20260130 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Person: Simone Montayne 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: https://dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions