f2e945b6-6e61-41c1-886c-b8d126dff00f_source eng; USA utf8 dataset Simone Montayne Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays pointOfContact 2022-05-06 ISO 19115 Geographic Information - Metadata ISO 19115:2003/Cor.1:2006(E) Lidar-derived elevation data for Eaglecrest ski area, Southeast Alaska, collected September 6, 2019 2022-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Wikstrom Jones, Katreen originator Wolken, G.J. originator https://doi.org/10.14509/30729 DIGITAL, ELEVATION, MODEL Raw Data File RDF 2021-10 8 p. The 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 Eaglecrest ski area and surroundings on Douglas Island, Southeast Alaska, during near snow-free ground conditions on September 6, 2019. The survey provides snow-free surface elevations for deriving snow depth distribution models with repeat surveys during snow-covered conditions. Aerial lidar were collected on September 6, 2019, and ground control data were collected on September 8, 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/10.14509/30729). 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. These data products were funded by U.S. Geological Survey 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. completed Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays 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. pointOfContact notPlanned Aerial Aerial Geology Avalanche DGGS Digital Elevation Model Digital Surface Model (DSM) Digital Terrain Model Elevation Emergency Preparedness Engineering Engineering Geology Environmental Geologic Geologic Hazards Geological Process Geology Geomorphology Geotechnical Hazards Hillshade Image LiDAR LiDAR Intensity Image LiDAR LAS File Format Point Cloud Data Raster Image Remote Sensing Slope Slope Instability Surface Surficial Surficial Geology Topography Water Web Service theme Alaska Division of Geological & Geophysical Surveys Cropley Lake Douglas Island Fish Creek Hilda Creek Juneau Mount Anderson Saddle Mountain Southeast Alaska place Alaska Division of Geological & Geophysical Surveys 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. otherRestrictions 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. otherRestrictions 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). Lidar-derived elevation data for Kensington Mine, Southeast Alaska 2020-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Wikstrom Jones, Katreen originator Wolken, G.J. originator Daanen, R.P. originator Herbst, A.M. originator https://doi.org/10.14509/30470 Raw Data File RDF 2020-7 5 p crossReference Lidar-derived elevation data for Mount Juneau, Southeast Alaska, collected September 6, 2019 2022-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Wikstrom Jones, Katreen originator Wolken, G.J. originator Herbst, A.M. originator https://doi.org/10.14509/30731 Raw Data File RDF 2021-12 8 p crossReference Lidar-derived elevation data for Speel Arm, Southeast Alaska, collected September 7, 2019 2022-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Wikstrom Jones, Katreen originator Wolken, G.J. originator Herbst, A.M. originator https://doi.org/10.14509/30730 Raw Data File RDF 2021-11 8 p crossReference grid eng; USA geoscientificInformation -134.572389 -134.466071 58.244507 58.322726 2019-09-06 >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 10.6 cm and the average density is 10.84 pts/m2. >digital surface model: The DSM represents surface elevations including heights of vegetation, buildings, bridges, etc. The DSM is a single band, 32-bit GeoTIFF file of 1-meter resolution. No Data value is set to -3.40282306074e+38 (32-bit, floating-point minimum). >digital terrain model: The DTM represents bare earth elevations, excluding vegetation, bridges, buildings, etc. The DTM is a single-band, 32-bit float GeoTIFF file of 1-meter resolution. No Data value is set to -3.40282306074e+38. >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 of 1-meter resolution. No Data value is set to -3.40282306074e+38. true digital elevation model unknown Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays 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. distributor Contact DGGS for current pricing Free download https://doi.org/10.14509/30729 digital elevation model classified point cloud data, digital surface model, digital terrain model and lidar intensity image information dataset Horizontal Positional Accuracy Report We did not measure horizontal accuracy for this collection. Vertical Positional Accuracy Report We measured a mean offset of +9 cm between 47 control points and the point cloud. We reduced this offset to -0.6 cm by performing a vertical transformation of the lidar point data. We used 13 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 5.6 cm. We evaluated the relative accuracy for this dataset as the interswath overlap consistency and measured it at 1.3 cm RMSE. See the accompanying report for tables of checkpoint comparisons. This data release is complete. This data release is complete. There is lower ground point density in some heavily forested areas than in areas with thinner forest canopy; however, the interpolated areas were deemed sufficient given the resolution of the products and intended scope of the work. This lineage was generated by the FGDC CSDGM to 19139 transformation 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 survey area covers 26 km2. We flew the aerial survey on September 6, 2019, with departure at 12:20 pm from Juneau International Airport, Alaska, and landed back at Juneau International Airport at 4:30 pm. The first part of the survey, covering Eaglecrest Ski Area, started and ended on Mount Anderson and was completed by 2:20 pm. The weather throughout the survey was clear with no wind. 2019-09-06T00:00:00 Lidar 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 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 point 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. 2019-01-01T00:00:00 otherRestrictions 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. unknown This metadata was automatically generated from the FGDC Content Standard for Digital Geospatial Metadata standard (version FGDC-STD-001-1998) using the 2019-08-12T11:11:00 version of the FGDC CSDGM to ISO 19139 transform. Simone Montayne Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays pointOfContact