{"action":"create","ckan_id":null,"date_created":"Sat, 21 Mar 2026 21:02:34 GMT","date_finished":null,"harvest_job_id":"79726ef4-fe9d-44a6-97a0-95f49b8db61f","harvest_source_id":"31f41541-38a0-400b-b240-10ebcb0acd9a","id":"e56edb54-ed7b-4c9f-904f-28160b495431","identifier":"https://dggs.alaska.gov/webpubs/metadata/RDF2021-11.xml","parent_identifier":null,"source_hash":"7fb5e9f42d721f5b578197b05a93dc4a70857812a6dfec875b3641d82a7a3248","source_raw":"Wikstrom Jones, KatreenWolken, G.J.2022Lidar-derived elevation data for Speel Arm, Southeast Alaska, collected September 7, 2019digital, elevation, modelRaw Data FileRDF 2021-11Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys8 p.https://doi.org/10.14509/30730The Alaska Division of Geological & Geophysical Surveys (DGGS) used aerial lidar to produce a classified point cloud, digital surface model (DSM), digital terrain model (DTM), and intensity model of a mountain slope adjacent to Speel Arm near Port Snettisham, Southeast Alaska, during near snow-free ground conditions on September 7, 2019. The survey provides snow-free surface elevations for deriving snow depth distribution models with repeat surveys during snow-covered conditions. Aerial lidar and ground control data were collected on September 7, 2019, and subsequently processed in a suite of geospatial processing software. These products are released as a Raw Data File with an open end-user license. All files can be downloaded from the Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/30730).The survey provides snow-free surface elevations for deriving snow depth distribution models with repeat surveys during snow-covered conditions. The goal of this project and related works is to improve understanding of the complex interaction between the changing cryosphere, snow avalanches, natural resources, and people in their natural and built environments.>classified point cloud data: Classified point cloud data are provided in compressed LAZ format. Data are classified in accordance with ASPRS 2014 guidelines and contain return and intensity information. The average pulse spacing is 3 cm and the average density is 48.5 pts/m2.\t\r\n>digital surface model: The DSM represents surface elevations including heights of vegetation, buildings, powerlines, etc. The DSM is a single band, 32-bit GeoTIFF file of 50-centimeter resolution. No Data value is set to -3.40282306074e+38 (32-bit, floating-point minimum).\t\r\n>digital terrain model: The DTM represents surface elevations of ground surfaces, excluding vegetation, bridges, buildings, etc. The DTM is a single-band, 32-bit float GeoTIFF file of 50-centimeter resolution. No Data value is set to -3.40282306074e+38.\t\r\n>lidar intensity image: The lidar intensity image describes the relative amplitude of reflected signals contributing to the point cloud. Intensity is largely a function of scanned object reflectance in relation to the signal frequency, is dependent on ambient conditions, and is not necessarily consistent between separate scans. The intensity image is a single-band, 32-bit float GeoTIFF file of 50-centimeter resolution. No Data value is set to -3.40282306074e+38.20190907ground conditioncompleteNone planned-133.808498-133.75364158.10888558.067564ISO 19115 Topic CategorygeoscientificInformationAlaska Division of Geological & Geophysical SurveysAerialAerial GeologyAvalancheDGGSDigital Elevation ModelDigital Surface Model (DSM)Digital Terrain ModelElevationEmergency PreparednessEngineeringEngineering GeologyEnvironmentalGeologicGeologic HazardsGeological ProcessGeologyGeomorphologyGeotechnicalHazardsHillshade ImageLiDARLiDAR Intensity ImageLiDAR LAS File FormatPoint Cloud DataRaster ImageRemote SensingSlopeSlope InstabilitySurfaceSurficialSurficial GeologyTopographyWaterWeb ServiceAlaska Division of Geological & Geophysical SurveysPort SnettishamSoutheast AlaskaThis 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).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.Alaska Division of Geological & Geophysical SurveysMetadata Managermailing and physical
3354 College Road
FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysPlease 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.These data products were funded by U.S. Geological Survey, Alaska Electric Light & Power and the State of Alaska and collected and processed by DGGS. We thank Coastal Helicopters for their aviation expertise and contribution to these data products. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.Wikstrom Jones, KatreenWolken, G.J.Daanen, R.P.Herbst, A.M.2020Lidar-derived elevation data for Kensington Mine, Southeast AlaskaRaw Data FileRDF 2020-7Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys5 phttps://doi.org/10.14509/30470Wikstrom Jones, KatreenWolken, G.J.Herbst, A.M.2022Lidar-derived elevation data for Eaglecrest ski area, Southeast Alaska, collected September 6, 2019Raw Data FileRDF 2021-10Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys8 phttps://doi.org/10.14509/30729Wikstrom Jones, KatreenWolken, G.J.Herbst, A.M.2022Lidar-derived elevation data for Mount Juneau, Southeast Alaska, collected September 6, 2019Raw Data FileRDF 2021-12Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys8 phttps://doi.org/10.14509/30731Not applicableThis data release is complete, and there was no over collect except for aircraft turns that were eliminated from the dataset. The data quality is consistent throughout the survey, apart from a sliver-shaped area in the center of the survey area where lack of overlap between the flightlines resulted in a gap in the lidar coverage. When we built the DSM and DTM in ArcGIS, we interpolated this area using Natural Neighbor void filling.This data release is complete.We did not measure horizontal accuracy for this collection.We measured a mean offset of -21.3 cm between 39 control points and the point cloud (appendix 1). We reduced this offset to -0.3 cm by performing a vertical transformation of the lidar point data. We used 12 check points to determine the non-vegetated vertical accuracy (NVA) of the point cloud ground class using a Triangulated Irregular Network (TIN) approach. We calculated the project NVA to have a root mean square error (RMSE) of 18.6 cm (appendix 2). We evaluated the relative accuracy for this dataset as the interswath overlap consistency and measured it at a 1.8 cm RMSE.Aerial photogrammetric survey - DGGS used a Riegl VUX1-LR laser scanner integrated with a global navigation satellite system (GNSS) and Northrop Grumman LN-200C inertial measurement unit (IMU). The lidar integration system was designed by Phoenix LiDAR Systems. The sensor can collect up to 820,000 points per second at a range of up to 150 m. The scanner operated with a pulse refresh rate of 50,000 pulses per second in the alpine areas and 400,000 pulses per second over forested areas at a scan rate between 80 and 220 lines per second. We used a Bell 206 JetRanger aircraft to survey from an elevation of ~130 m above ground level, at a ground speed of approximately 30 m/s, and with a scan angle set from 80 to 280 degrees. The total surveyed area covers ~6 km2. We flew the aerial survey on September 7, 2019, with departure at 3:20 pm from Speel Arm Balcony weather station and landed back at the same location at 4:45 pm. The weather throughout the survey was clear with no wind.20190906Lidar dataset processing - We processed point data in SDCimport software for initial filtering and multiple-time-around (MTA) disambiguation. MTA errors, corrected in this process, are the result of ambiguous interpretations of received pulse time intervals and occur more frequently with higher pulse refresh rates. We processed Inertial Measurement Unit (IMU) and Global Navigation Satellite System (GNSS) data in Inertial Explorer and we used Spatial Explorer software to integrate flightline information with the point cloud. 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. We created macros in Terrasolid software and classified points in accordance with American Society for Photogrammetry and Remote Sensing (ASPRS) 2014 guidelines. We gave careful attention to the interpolation of the project's ground surface to compensate for inconsistent penetration through low vegetation as a function of the scan angle. Once classified, we applied a geometric transformation and converted the points from ellipsoidal heights to GEOID12B (Alaska) orthometric heights. We used ArcMap to derive raster products from the point cloud. The DSM was interpolated from maximum return values from the ground, vegetation and building classes using a binning method. The DTM was interpolated from all ground class returns also using a binning method and minimum values. In ArcMap, we produced an intensity image using closest-to-mean binning.2019rasterUniversal Transverse Mercator80.999600-1350500000.0000000coordinate pair.00000001.00000001MetersNAD83 (2011)GRS 806378137298.257222101000025NAVD88, GEOID12B0.001metersExplicit elevation coordinate included with horizontal coordinatesclassified point cloud dataClassified point cloud data are provided in compressed LAZ format. Data are classified in accordance with ASPRS 2014 guidelines and contain return and intensity information. The average pulse spacing is 3 cm and the average density is 48.5 pts/m2.DGGSclassified point cloud datadigital surface modelThe DSM represents surface elevations including heights of vegetation, buildings, powerlines, etc. The DSM is a single band, 32-bit GeoTIFF file of 50-centimeter resolution. No Data value is set to -3.40282306074e+38 (32-bit, floating-point minimum).DGGSdigital surface modeldigital terrain modelThe DTM represents surface elevations of ground surfaces, excluding vegetation, bridges, buildings, etc. The DTM is a single-band, 32-bit float GeoTIFF file of 50-centimeter resolution. No Data value is set to -3.40282306074e+38.DGGSdigital terrain modellidar intensity imageThe lidar intensity image describes the relative amplitude of reflected signals contributing to the point cloud. Intensity is largely a function of scanned object reflectance in relation to the signal frequency, is dependent on ambient conditions, and is not necessarily consistent between separate scans. The intensity image is a single-band, 32-bit float GeoTIFF file of 50-centimeter resolution. No Data value is set to -3.40282306074e+38.DGGSlidar intensity imageAlaska Division of Geological & Geophysical SurveysMetadata Managermailing and physical
3354 College Road
FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysPlease 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.RDF 2021-11The 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.Contact DGGS for current pricingdigital elevation model20220211classified point cloud data, digital surface model, digital terrain model and lidar intensity imagehttps://doi.org/10.14509/30730Free download20220212Alaska Division of Geological & Geophysical SurveysSimone MontayneMetadata Managermailing and physical
3354 College Road
FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysFGDC Content Standard for Digital Geospatial MetadataFGDC-STD-001-1998If 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.https://dggs.alaska.gov/metadata/dggs.extdggs metadata extensions","source_transform":null,"status":"error"}