Wikstrom Jones, Katreen Wolken, G.J. Daanen, R.P. Herbst, A.M. 2020 imagery Raw Data File RDF 2020-7 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 5 p. https://doi.org/10.14509/30470 The State of Alaska Division of Geological & Geophysical Surveys (DGGS) used lidar to produce a digital terrain model (DTM) and digital surface model (DSM) of Kensington Mine, southeast Alaska, during snow-free ground conditions. The lidar and Global Navigation Satellite System (GNSS) data were collected on September 7, 2019, and processed using Terrasolid. This data 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 Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/30470). The goal of the survey is to provide snow-free surface elevations for the purpose of deriving snow depth distribution models with repeat surveys during snow-covered surface conditions. This data release is one of a series of DGGS publications to present elevation data. >classified point cloud data: Classified point cloud data is provided in this collection in compressed .laz format. Data are classified in accordance with ASPRS 2014 guidelines and contain return and intensity information. >digital surface model: The DSM represents surface elevations, for example, heights of vegetation, buildings, bridges, etc. The DSM is a single band, 32-bit GeoTIFF file, with a ground sample distance of 0.5 meters. No Data value is set to -3.40282306074e+038. >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, with a ground sample distance of 0.5 meter. No Data value is set to -3.40282306074e+038. >lidar intensity image: The lidar intensity image describes the relative amplitude of reflected signals, contributing to the point cloud. Lidar 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 with a ground sample distance of 0.5 meters. No Data value is set to -3.40282306074e+038 (32-bit, floating-point minimum). 20190907 20191024 ground condition complete None planned -135.079056 -135.019158 58.879165 58.821644 ISO 19115 Topic Category geoscientificInformation Alaska Division of Geological & Geophysical Surveys Digital Elevation Model Digital Surface Model (DSM) Digital Terrain Model Engineering Engineering Geology Geologic Geology Geomorphology Geotechnical LiDAR LiDAR Intensity Image LiDAR LAS File Format Point Cloud Data Remote Sensing Surface Surficial Surficial Geology Topography Web Service Alaska Division of Geological & Geophysical Surveys Johnson Creek Jualin Mine Juneau Mining District Lions Head Mountain Snowslide Gulch Southeast Alaska 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). 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 Surveys Metadata Manager mailing and physical

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Fairbanks AK 99709-3707 USA (907)451-5020 (907)451-5050 dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays These data products were funded by U.S. Geological Surveys, Kensington Mine (Coeur Mining) and Alaska Department of Natural Resources, Division of Geological & Geophysical Surveys. We thank Coastal Helicopters for their aviation expertise and contribution to these data products. Wolken, G.J. Hendricks, K.A. Daanen, R.P. Overbeck, J.R. Stevens, D.S.P. Masterman, S.S. 2017 Information Circular IC 64 Fairbanks, Alaska, United States Alaska Division of Geological & Geophysical Surveys 2 p https://doi.org/10.14509/29781 Not applicable There are a few areas where data coverage is limited due to laser range exceedance, which is related to the slow response of the fixed-wing aircraft to the fast elevation change along the flight path (e.g., in canyons). Relative accuracy for this dataset was evaluated as the interswath overlap consistency and was measured at 0.56 cm RMSE. The accompanying report provides additional detail regarding tests used to determine data fidelity. This data release is complete, and there is no over collect, except for the aircraft turns that were eliminated from the dataset. Horizontal accuracy was not measured for this collection. The elevation values of 59 ground control points were compared with the elevation values of the lidar points classified as Grounds. The average vertical offset was corrected with a z-transformation. 16 checkpoints were used to determine the final accuracy of the z-transformed lidar point cloud. The lidar point cloud had a vertical offset of +14.4 cm (Root mean squared error [RMSE] 18.7 cm) compared to ground control; therefore, a vertical transformation of -14.4 cm was applied to the lidar point cloud. The final accuracy assessment showed a mean vertical offset of -8.24 cm and RMSE of 17.6 cm. Relative accuracy for this dataset was evaluated as the interswath overlap consistency and was measured at 0.56 cm RMSE. A table of checkpoints and errors is provided in the accompanying report. Data acquisition - This lidar survey was flown on September 7, 2019 at an average elevation of 130 m above ground level and a ground speed of approximately 30 m/s with a helicopter configuration, using a Bell 206 JetRanger. Elevation data were acquired with a Riegl VUX1-LR laser scanner integrated with a GNSS and Northrop Grumman IMU system. The integration was designed by Phoenix LiDAR systems. Lidar data were acquired at a pulse rate ranging from 50,000 pulses per second in the alpine areas to 400,000 pulses per second over forested areas, a scan rate of 200 revolutions per second, and a scan angle range of 80-280 degrees. 20190907 Ground survey - Ground control and checkpoints were collected on October 24, 2019. A Trimble R7 GNSS receiver with Zephyr-2 antenna was deployed near the center of the study area. It provided a base station occupation and real-time kinematic (RTK) corrections to points surveyed with a rover Trimble R8-4 GNSS receiver (internal antenna). 76 ground control points and checkpoints were collected to be used for calibration and assessment of the vertical accuracy of the point cloud. All points were collected on a paved road surface. 20191024 Point classification - Raw data were processed using Terrasolid software to produce integrated files for navigation correction and a point cloud for calibration. The navigation was corrected using Inertial Explorer software. The software integrates the GNSS and IMU data to establish the correct flight path and orientation of the lidar sensor. Internal consistency within the dataset was improved by calibrating the point cloud data using global, flight line, and fluctuation (within individual flightlines) tielines in TerraSolid software. The point cloud data were classified for ground points as well as low, medium, and high vegetation (0.01-0.5 m, 0.5-3 m, and 3-60 m heights above the ground, respectively). Some manual processing was required to eliminate erratically placed points and misclassified ground points. All low points and air points were eliminated from the dataset. 2020 Raster products - A LAS dataset was created in ArcMap, from which a 50-cm DTM, 50-cm DSM, and 1-m intensity image were produced. The DTM was derived from elevation values of Ground-classified points only and built using the binning technique of minimum elevation and linear void fill. The DTM was derived from elevation values from first returns from the Grounds, Low Vegetation, Medium Vegetation, or High Vegetation classes, and built using the binning technique of average elevation values and linear void fill. The intensity image was derived from the intensity values of the first return points. 2020 raster Universal Transverse Mercator 8 0.999600 -135 0 500000.000000 0 coordinate pair .00000001 .00000001 Meters North American Datum of 1983 (2011) GRS 80 6378137 298.257222101000025 NAVD88, GEOID12B 0.5 meters Explicit elevation coordinate included with horizontal coordinates classified point cloud data Classified point cloud data is provided in this collection in compressed .laz format. Data are classified in accordance with ASPRS 2014 guidelines and contain return and intensity information. Alaska Division of Geological & Geophysical Surveys (DGGS) classified point cloud data digital surface model The DSM represents surface elevations, for example, heights of vegetation, buildings, bridges, etc. The DSM is a single band, 32-bit GeoTIFF file, with a ground sample distance of 0.5 meters. No Data value is set to -3.40282306074e+038. Alaska Division of Geological & Geophysical Surveys (DGGS) digital surface model 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, with a ground sample distance of 0.5 meter. No Data value is set to -3.40282306074e+038. Alaska Division of Geological & Geophysical Surveys (DGGS) digital terrain model lidar intensity image The lidar intensity image describes the relative amplitude of reflected signals, contributing to the point cloud. Lidar 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 with a ground sample distance of 0.5 meters. No Data value is set to -3.40282306074e+038 (32-bit, floating-point minimum). Alaska Division of Geological & Geophysical Surveys (DGGS) lidar intensity image Alaska Division of Geological & Geophysical Surveys Metadata Manager mailing and physical

3354 College Road

Fairbanks AK 99709-3707 USA (907)451-5020 (907)451-5050 dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays RDF 2020-7 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. 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 pricing imagery 20201113 classified point cloud data, digital surface model, digital terrain model, and lidar intensity image https://doi.org/10.14509/30470 Free download 20201118 Alaska Division of Geological & Geophysical Surveys Simone Montayne Metadata Manager mailing and physical

3354 College Road

Fairbanks AK 99709-3707 USA (907)451-5020 (907)451-5050 dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 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. https://dggs.alaska.gov/metadata/dggs.ext dggs metadata extensions