gov.noaa.nmfs.inport:68619 eng UTF8 dataset Elevation OCM Partners resourceProvider NOAA Office for Coastal Management (843) 740-1202 2234 South Hobson Ave Charleston SC 29405-2413 coastal.info@noaa.gov https://coast.noaa.gov WWW:LINK-1.0-http--link NOAA Office for Coastal Management Website NOAA Office for Coastal Management Home Page information pointOfContact 2026-03-04T19:17:17 ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for imagery and gridded data ISO 19115-2:2009(E) EPSG::6337 EPSG::5703 2018 AK DGGS Lidar DEM: Chilkat Ridge, Alaska ak2018_chilkat_m9672_metadata 2018-01-01 creation 2019 publication NOAA/NMFS/EDM 68619 https://www.fisheries.noaa.gov/inport/item/68619 WWW:LINK-1.0-http--link Full Metadata Record View the complete metadata record on InPort for more information about this dataset. information https://coast.noaa.gov/ WWW:LINK-1.0-http--link NOAA's Office for Coastal Management (OCM) website Information on the NOAA Office for Coastal Management (OCM) download https://coast.noaa.gov/dataviewer/ WWW:LINK-1.0-http--link NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV) The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer. download https://dggs.alaska.gov/webpubs/dggs/rdf/text/rdf2019_007.pdf WWW:LINK-1.0-http--link Lidar Report This lidar report provides accompanying information about the collection and processing of this lidar data set. download The State of Alaska Division of Geological & Geophysical Surveys (DGGS) used lidar to produce a digital terrain model (DTM) and digital surface model (DSM) over ridgelines along the Chilkat River just north of Haines, Alaska. The lidar and Global Navigation Satellite System (GNSS) data were collected on November 15-16, 2018, and processed using Terrasolid. This data collection is being released as a Raw Data File with an open end-user license. The complete report and digital data are available from the DGGS website: http://doi.org/10.14509/30224. The NOAA Office for Coastal Management (OCM) downloaded this data set from this AK DGGS site: https://elevation.alaska.gov/ This file was processed to make the data available for custom and bulk download from the NOAA Digital Coast Data Access Viewer (DAV) . The total number of files downloaded and processed was 1. This dataset includes point cloud data, a 32-bit digital terrain model, and an intensity image covering a study area near the Chilkat Ridge region of southeast Alaska. The data release is one of a series of Alaska Division of Geological & Geophysical Surveys (DGGS) publications to present elevation data. The goal is to provide information for the Alaska Division of Forestry on the ground conditions and tree cover on Chilkat Ridge. These data products were funded by the Alaska Division of Forestry. We thank Clearwater Air from Anchorage for their aviation expertise and contribution to these data products., Daanen, R.D. Wikstrom Jones, Katreen Wolken, G.J. Herbst, A.M. completed NOAA Office for Coastal Management (843) 740-1202 2234 South Hobson Ave Charleston SC 29405-2413 coastal.info@noaa.gov https://coast.noaa.gov WWW:LINK-1.0-http--link NOAA Office for Coastal Management Website NOAA Office for Coastal Management Home Page information pointOfContact NOAA Office for Coastal Management (843) 740-1202 2234 South Hobson Ave Charleston SC 29405-2413 coastal.info@noaa.gov https://coast.noaa.gov WWW:LINK-1.0-http--link NOAA Office for Coastal Management Website NOAA Office for Coastal Management Home Page information custodian notPlanned EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > DIGITAL ELEVATION/TERRAIN MODEL (DEM) EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION theme Global Change Master Directory (GCMD) Science Keywords 17.0 CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > ALASKA VERTICAL LOCATION > LAND SURFACE place Global Change Master Directory (GCMD) Location Keywords 20.8 LIDAR > Light Detection and Ranging instrument Global Change Master Directory (GCMD) Instrument Keywords 17.2 Airplane > Airplane platform Global Change Master Directory (GCMD) Platform Keywords 17.2 Anman Creek Birch Island Chilkat Chilkat Lake Chilkat River Chilkat River State Critical Habitat Area Dalton Trail Juneau Mining District Kicking Horse River Klehini River Kohklux Porcupine Creek Mining District Southeast Alaska Takhin River Tsirku River place Alaska Division of Geological & Geophysical Surveys DEMs - partner (no harvest) project InPort otherRestrictions Cite As: OCM Partners, [Date of Access]: 2018 AK DGGS Lidar DEM: Chilkat Ridge, Alaska [Data Date Range], https://www.fisheries.noaa.gov/inport/item/68619. NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose. otherRestrictions Access Constraints: None otherRestrictions Use Constraints: Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. otherRestrictions 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. Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners. unclassified NOAA Data Management Plan (DMP) NOAA/NMFS/EDM 68619 https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ocmp/dmp/pdf/68619.pdf WWW:LINK-1.0-http--link NOAA Data Management Plan (DMP) NOAA Data Management Plan for this record on InPort. information crossReference grid eng; US elevation geoscientificInformation -135.97071 -135.640466 59.236685 59.414268 | Currentness: Ground Condition 2018-11-15 2018-11-16 >point_cloud_data: Classified (ASPRS standard) lidar values for all returns; File format: LAS 1.4. >dtm: DTMs represent surface elevations of ground surfaces, excluding vegetation, bridges, buildings, etc. The DTM is a single-band, 1 meter, 32-bit float GeoTIFF file, with a ground sample distance (GSD) of 15 cm on the ground and 60 cm below dense vegetation. No Data value is set to -3.40282306074e+038. >dsm: A 2-meter DSM raster was created from the first returns of the laser point cloud. The No Data value is set to -3.40282306074e+038. >intensity_image: A grayscale image that displays 0-255 grayscale values according to relative reflectivity. The laser intensity image is provided as a 1-meter raster. Zip Zip GeoTIFF NOAA Office for Coastal Management (843) 740-1202 2234 South Hobson Ave Charleston SC 29405-2413 coastal.info@noaa.gov https://coast.noaa.gov WWW:LINK-1.0-http--link NOAA Office for Coastal Management Website NOAA Office for Coastal Management Home Page information distributor https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9672/details/9672 WWW:LINK-1.0-http--link Customized Download Create custom data files by choosing data area, map projection, file format, etc. A new metadata will be produced to reflect your request using this record as a base. download https://noaa-nos-coastal-lidar-pds.s3.us-east-1.amazonaws.com/dem/AK_Chilkat_DEM_2018_9672/index.html WWW:LINK-1.0-http--link Bulk Download Bulk download of data files in the original coordinate system. download dataset Horizontal Positional Accuracy Horizontal accuracy was not evaluated for this project. Vertical Positional Accuracy The Root Mean Square Error of the final data layers for the bare earth elevation between the checkpoints and lidar ground points is 8.5 centimeters. Completeness Report The total area surveyed was approximately 224 km2. This data release is complete and there is no over-collect, except for the aircraft turns that were eliminated from the dataset. There are a few areas where data coverage is limited due to the slow response of the fixed wing aircraft the fast elevation changes along the flight path, e.g., canyons. Void areas for lakes and ponds, which were hydroflattened in the elevation models, were delineated as null data in the intensity rasters. Conceptual Consistency To evaluate data consistency, ground checkpoints were collected (November 15, 2018) as RTK-GNSS points 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. The checkpoints were compared with the DTM. The comparison showed a 7.1 cm average magnitude difference between the checkpoints and the DTM. The checkpoint differences had a Root Mean Square Error of 8.5 cm and a standard deviation of 8.6 cm. Lidar data acquisition - DGGS operates a Riegle VUX1-LR lidar integrated with a GNSS and Northrop Grumman IMU system. The integration was designed by Phoenix LiDAR systems. The sensor is capable of collecting up to 820,000 points per second over a distance of 150 m. This survey was flown at a scan rate of 400,000 points per second and a scan rate of 200 revolutions per second. The average pulse spacing was 15 cm and the average point density was 40 points per square meter. This survey was flown with an average elevation of 200 m above ground level and a ground speed of approximately 40 m/s with a fixed-wing aircraft configuration, using Cessna 185. The scan angle was set from 55 to 305. Ground Control points were collected using a Trimble system consisting of a Trimble R7 base station and an R8 rover system. 2018-01-01T00:00:00 Raw lidar data processing - 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, where the GNNS and IMU data are integrated to establish the correct flight path and orientation of the lidar sensor. 2018-01-01T00:00:00 Point cloud data calibration - Internal lidar point cloud data were calibrated using Terrasolid software. The initial accuracy of the point cloud was 8.346 cm. After calibration, the point cloud had an average magnitude accuracy of 6.914 cm. 2018-01-01T00:00:00 Point cloud data classification - The point cloud is classified for ground points as well as low, medium, and high vegetation (0.01-0.3 m, 0.3-5 m, and 5-60 m heights above the ground, respectively). Some manual processing was required to eliminate fog and misclassified ground points. All low points and air points are eliminated from the dataset. Lastly, the DSM and DTM were hydroflattened to mean surrounding elevation for all lakes and ponds. 2018-01-01T00:00:00 Digital terrain model - The ground points from the final point cloud were used to build the digital terrain model in ArcGIS. The point cloud was loaded as a las dataset and filtered for ground points. The remaining points were used in a las dataset-to-raster conversion tool. Rasters, with a ground pixel resolution of 1 meter, were derived from mean values from a 2-meter sampling distance. The DTM was hydroflattened to mean surrounding elevation for all lakes and ponds. 2019-01-01T00:00:00 Digital surface model - The digital surface model was created from the first returns in the point cloud. Due to a large number of points in vegetation, we used a binning method with natural neighbor gap-filling. The 1 m bins did not gap-fill correctly in the entire dataset, however, so we opted to store the DSM in a 2-m-resolution raster. The DSM was hydroflattened to mean surrounding elevation for all lakes and ponds. 2019-01-01T00:00:00 Intensity image - The intensity raster was generated using the ground points. The raster resolution is 1-meter. 2019-01-01T00:00:00 The NOAA Office for Coastal Management (OCM) downloaded 1 raster DEM file in GeoTiff format from the Alaska DGGS Elevation Portal. The data were in UTM Zone 8N NAD83 (2011), meters coordinates and NAVD88 (Geoid12B) elevations in meters. The bare earth raster file was at a 1 meter grid spacing. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. Used an internal script to assign the EPSG codes (Horizontal EPSG: 6337 and Vertical EPSG: 5703) to the GeoTiff formatted file. 2. Copied the files to https. 2022-11-29T00:00:00 Office for Coastal Management processor Alaska Division of Geological and Geophysical Surveys (AK DGGS) AK DGGS https://elevation.alaska.gov/ WWW:LINK-1.0-http--link AK DGGS Elevation Portal Source Citation URL information originator