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OCM Partners Metadata Library > Lidar - partner (no harvest) >

2023 AK DGGS Lidar: Wrangell Island, AK

Data Set (DS)  |  OCM Partners (OCMP)
GUID: gov.noaa.nmfs.inport:72046  |  Updated: March 7, 2024  |  Published / External 
Summary
Item Identification
Keywords
Physical Location
Data Set Info
Support Roles
Extents
Spatial Info
Access Info
Distribution Info
URLs
Data Quality
Data Management
Lineage
Related Items
Catalog Details

Summary

Browse Graphic

Short Citation
OCM Partners, 2024: 2023 AK DGGS Lidar: Wrangell Island, AK, https://www.fisheries.noaa.gov/inport/item/72046.
Full Citation Examples

Abstract

Lidar-derived elevation data for Wrangell Island, Southeast Alaska, collected July 2023, Raw Data File 2023-28, provides lidar-derived classified point cloud, a digital surface model (DSM), a digital terrain model (DTM), and an intensity model of Wrangell Island, Southeast Alaska, during leaf-on ground conditions. The survey provides snow-free surface elevations for use in shoreline development, resource quantification, hydrographic mapping, and slope stability modeling. Ground control data were collected June 26-30, 2023, and aerial lidar data were collected July 7-11, 2023, and subsequently merged and processed using a suite of geospatial processing software. All files can be downloaded from the Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/31098).

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV).

The NOAA Office for Coastal Management (OCM) downloaded laz point data files from the AK DGGS (Alaska Division of Geological and Geophysical Surveys) website (https://dggs.alaska.gov/pubs/id/31098) . The data were processed to the NOAA Digital Coast Data Access Viewer (DAV) to make the data available for bulk and custom downloads. In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data are also available. These data are available for custom download at the link provided in the URL section of this metadata record.

Distribution Information

  • Not Applicable

    Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base. Change to an orthometric vertical datum is one of the many options.

  • LAS/LAZ - LASer

    Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document. They will be in an orthometric datum.

Access Constraints:

None

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. 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.

Controlled Theme Keywords

COASTAL ELEVATION, elevation, TERRAIN ELEVATION

Child Items

No Child Items for this record.

Contact Information

Point of Contact
NOAA Office for Coastal Management (NOAA/OCM)
coastal.info@noaa.gov
(843) 740-1202

Metadata Contact
NOAA Office for Coastal Management (NOAA/OCM)
coastal.info@noaa.gov
(843) 740-1202

Extents

Geographic Area 1

-132.396167° W, -131.920007° E, 56.494219° N, 56.115756° S

Time Frame 1
2023-07-07 - 2023-07-11

Dates of collection

Item Identification

Title: 2023 AK DGGS Lidar: Wrangell Island, AK
Short Name: ak2023_wrangell_m10045
Status: Completed
Creation Date: 2023
Publication Date: 2023
Abstract:

Lidar-derived elevation data for Wrangell Island, Southeast Alaska, collected July 2023, Raw Data File 2023-28, provides lidar-derived classified point cloud, a digital surface model (DSM), a digital terrain model (DTM), and an intensity model of Wrangell Island, Southeast Alaska, during leaf-on ground conditions. The survey provides snow-free surface elevations for use in shoreline development, resource quantification, hydrographic mapping, and slope stability modeling. Ground control data were collected June 26-30, 2023, and aerial lidar data were collected July 7-11, 2023, and subsequently merged and processed using a suite of geospatial processing software. All files can be downloaded from the Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/31098).

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV).

The NOAA Office for Coastal Management (OCM) downloaded laz point data files from the AK DGGS (Alaska Division of Geological and Geophysical Surveys) website (https://dggs.alaska.gov/pubs/id/31098) . The data were processed to the NOAA Digital Coast Data Access Viewer (DAV) to make the data available for bulk and custom downloads. In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data are also available. These data are available for custom download at the link provided in the URL section of this metadata record.
Purpose:

The survey provides snow-free surface elevations for use in shoreline development, resource quantification, hydrographic mapping, and slope stability modeling.
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 LASer (LAS) format. Data are classified following ASPRS 2019 guidelines (table 2) and contain return and intensity information. For all ground points, the average point spacing is 54.6 cm, and the average density is 3.35 pts/m2.

>dsm: The DSM represents surface elevations, including heights of vegetation, buildings, powerlines, bridge decks, etc. The DSM is a single-band, 32-bit GeoTIFF file of 50-cm resolution. No Data value is set to -9999.

>dtm: The DTM represents bare earth elevations, excluding vegetation, bridge decks, buildings, etc. The DTM is a single-band, 32-bit GeoTIFF file of 50-cm resolution. No Data value is set to -9999.

>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, 16-bit unsigned GeoTIFF file of 50-cm resolution. No Data value is set to 0.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
ISO 19115 Topic Category
elevation

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > ALASKA
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > LAND SURFACE

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords
LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords
Airplane > Airplane

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: None Planned
Data Presentation Form: Model (digital)
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.
Data Set Credit: This survey area is on the traditional homelands of the Stikine Tlingit people. For this project, we partnered with the U.S. Forest Service to cost-share the acquisition of lidar data in an area of mutual interest. We thank Clearwater Air for their aviation expertise and contribution to these data products, Dustin Wittwer and Joe Delabrue of the U.S. Forest Service for logistical help, and David Ciampa and Amy Helkenn of the Alaska Division of Mining, Land and Water for providing ground control points. 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., Zechmann, J.M. Wikstrom Jones, K.M. Wolken, G.J.

Support Roles

Data Steward

CC ID: 1323049
Date Effective From: 2024
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 1323048
Date Effective From: 2024
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 1323050
Date Effective From: 2024
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 1323051
Date Effective From: 2024
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1323054
W° Bound: -132.396167
E° Bound: -131.920007
N° Bound: 56.494219
S° Bound: 56.115756

Extent Group 1 / Time Frame 1

CC ID: 1323053
Time Frame Type: Range
Start: 2023-07-07
End: 2023-07-11
Description:

Dates of collection

Spatial Information

Spatial Representation

Representations Used

Grid: No
Vector: Yes
Text / Table: No
TIN: No
Stereo Model: No
Video: No

Vector Representation 1

CC ID: 1323044
Point Object Present?: Yes
Point Object Count: 91667794

Reference Systems

Reference System 1

CC ID: 1323045

Coordinate Reference System
CRS Type: Geographic 3D
EPSG Code: EPSG:6319
EPSG Name: NAD83(2011)
▾ See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for bulk and custom downloads.
Data Access Constraints:

None
Data 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. 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.

Distribution Information

Distribution 1

CC ID: 1323055
Start Date: 2024-02-01
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=10045/details/10045
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2024 - Present)
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base. Change to an orthometric vertical datum is one of the many options.
Distribution Format: Not Applicable
Compression: Zip

Distribution 2

CC ID: 1323056
Start Date: 2024-02-01
End Date: Present
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/10045/index.html
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2024 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document. They will be in an orthometric datum.
Distribution Format: LAS/LAZ - LASer
Compression: LAZ

URLs

URL 1

CC ID: 1323047
URL: https://coast.noaa.gov/dataviewer/
Name: NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV)
URL Type:
Online Resource
File Resource Format: HTML
Description:

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.

URL 2

CC ID: 1323352
URL: https://dggs.alaska.gov/webpubs/dggs/rdf/text/rdf2023_028.pdf
Name: Lidar Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to the lidar report.

URL 3

CC ID: 1323353
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/10045/supplemental/ak2023_wrangell_m10045.kmz
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic displays the footprint for this lidar data set.

URL 4

CC ID: 1323354
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/entwine/geoid12b/10045/ept.json
Name: Entwine Point Tile (EPT)
URL Type:
Online Resource
File Resource Format: json
Description:

Entwine Point Tile (EPT) is a simple and flexible octree-based storage format for point cloud data. The data is organized in such a way that the data can be reasonably streamed over the internet, pulling only the points you need. EPT files can be queried to return a subset of the points that give you a representation of the area. As you zoom further in, you are requesting higher and higher densities. A dataset in EPT will contain a lot of files, however, the ept.json file describes all the rest. The EPT file can be used in Potree and QGIS to view the point cloud.

URL 5

CC ID: 1323355
URL: https://coast.noaa.gov/lidar/viewer/v/noaapotree.html?m=10045&g=geoid12b
Name: Potree 3D View
URL Type:
Online Resource
Description:

Link to view the point cloud (using the Entwine Point Tile (EPT) format) in the 3D Potree viewer.

URL 6

CC ID: 1323356
URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=10046/details/10046
Name: Custom DEM Download
URL Type:
Online Resource
File Resource Format: Zip
Description:

Link to custom download, from the Data Access Viewer (DAV), the raster Digital Elevation Model (DEM) data that were created from this lidar data set.

Data Quality

Horizontal Positional Accuracy:

We did not measure horizontal accuracy for this collection.
Vertical Positional Accuracy:

We measured a mean offset of +94.3 cm between 43 control points and the point cloud. This offset was reduced to +0.9 cm in non-vegetated areas and +10.5 cm in vegetated areas by applying a rubber-sheet vertical correction to the lidar point data. We used 214 checkpoints to determine the vertical accuracy of the point cloud ground class using a Triangulated Irregular Network (TIN) approach. The project vertical accuracy has a root mean square error (RMSE) of 5.3 cm in non-vegetated areas and 17.4 cm RMSE in vegetated areas. We evaluated the relative accuracy for this dataset as the interswath overlap consistency and measured it at 6.4 cm RMSE.
Completeness Report:

This data relaease is complete.
Conceptual Consistency:

This is a full-release dataset. There was no over-collect. Data quality is consistent throughout the survey.

Data Management

Have Resources for Management of these Data Been Identified?: Yes
Approximate Percentage of Budget for these Data Devoted to Data Management: Unknown
Do these Data Comply with the Data Access Directive?: Yes
Actual or Planned Long-Term Data Archive Location: NCEI-NC
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?:

Data is backed up to cloud storage.

Lineage

Lineage Statement:

Data were collected by the Alaska Division of Geological and Geophysical Surveys (AK DGGS). The data were downloaded by the NOAA Office for Coastal Management (OCM) and processed to make it available for custom download from the NOAA Digital Coast Data Access Viewer (DAV) and for bulk download from S3 AWS.

Sources

Data Downloaded from the AK DGGS

CC ID: 1323357
Contact Role Type: Publisher
Contact Type: Organization
Contact Name: AK DGGS
Citation URL: https://dggs.alaska.gov/webpubs/data/rdf2023_028_lidar-wrangell-2023-classified_points.zip
Citation URL Name: Download zipfile for the 2023 AK DGGS Wrangell Island, AK lidar

Process Steps

Process Step 1

CC ID: 1323040
Description:

Ground survey - Ground control points were collected June 26-30, 2023, by the Alaska Division of Mining, Land and Water (DMLW). They deployed a Trimble R12 GNSS receiver to provide a base station occupation and real-time kinematic (RTK) corrections to points they surveyed with a rover Trimble R12i GNSS receiver/TSC5 controller. Benchmark HH-2 (PID BBDX58), located on the Heritage Harbor breakwater in Wrangell, served as the base station location. DMLW collected 43 ground control points and 214 checkpoints to use for calibration and assess the vertical accuracy of the point cloud. Checkpoints were collected in forest, shrubland, grassland, sphagnum bog, bare earth, and paved surfaces. We processed and delivered all data in NAD83 (2011) UTM8N and vertical datum NAVD88 GEOID12B.
Process Date/Time: 2023-06-30 00:00:00

Process Step 2

CC ID: 1323041
Description:

Aerial photogrammetric survey - DGGS used a Riegl VUX1-LR22 laser scanner integrated with a global navigation satellite system (GNSS) and Northrop Grumman LN-200C inertial measurement unit (IMU) designed by Phoenix LiDAR Systems. The sensor can collect a maximum of 1,500,000 points per second at a range of 150 m, or a minimum of 50,000 points per second at a range of 640 m. The scanner operated with a pulse refresh rate of 600,000 pulses per second over forested terrain, and 200,000 pulses per second over alpine terrain, with a scan rate between 50 and 200 lines per second. We used a Cessna 180 fixed-wing platform to survey from an elevation of approximately 150-350 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 survey area covers approximately 565 km2. The survey area was accessed by air from Wrangell Airport. See table 1 of the accompanying report for data collection start and end times, and weather conditions.
Process Date/Time: 2023-07-11 00:00:00

Process Step 3

CC ID: 1323042
Description:

Lidar dataset processing - We processed point data in Spatial Explorer 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. We processed IMU and GNSS data 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. We created macros in Terrasolid software and classified points in accordance with the American Society for Photogrammetry & Remote Sensing (ASPRS) 2019 guidelines (ASPRS, 2019). Once classified, we applied a geometric transformation and converted the points from ellipsoidal heights to GEOID12B (Alaska) orthometric heights. We used ArcGIS Pro to derive raster products from the point cloud. A 50-cm DSM was interpolated from maximum return values from ground, vegetation, bridge deck, and building classes using a binning method and maximum values. A 50-cm DTM was interpolated from all ground class returns using a binning method and minimum values. We also produced an intensity image for the entire area using average binning in ArcGIS Pro, with no normalization or corrections applied.
Process Date/Time: 2023-01-01 00:00:00

Process Step 4

CC ID: 1323358
Description:

The NOAA Office for Coastal Management (OCM) downloaded 565 laz point data files from the Alaska Division of Geological and Geophysical Surveys (AK DGGS).

The data were in UTM Zone 8 (NAD83 2011), meters coordinates and NAVD88 (Geoid12b) elevations in meters. The data were classified as: 1 - Unclassified, 2 - Ground, 3 - Low Vegetation (>0.0m ,<0.5 m), 4 - Medium Vegetation (>0.5 m, <3 m), 5 - High Vegetation (>3m, < /= 60m), 6 - Building, 7 - Low Noise, 17 - Bridge Decks, 18 - High Noise, 30 - Noise, Manually Classified. There were also points that were classified as 19 and 31 that were not listed in either the lidar report or in the provided metadata. These points were assumed to be Noise classes by OCM and this was confirmed by AK DGGS. OCM re-classified the Class 19, 30, and 31 points to Class 18 - High Noise. OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV), the classes available on the DAV are: 1, 2, 3, 4, 5, 6, 7, 17, 18.

OCM performed the following processing on the data for Digital Coast storage and provisioning purposes:

1. Internal OCM scripts were run to check the number of points by classification and by flight ID and the gps, elevation, and intensity ranges.

2. Internal OCM scripts were run on the laz files to:

a. Re-classify points that were classified as 19, 30, and 31 to Class 18 - High Noise

b. Convert from orthometric (NAVD88) elevations to NAD83 (2011) ellipsoid elevations using the Geoid12b model

c. Convert the laz files from UTM Zone 8 (NAD83 2011), meters coordinates to geographic coordinates

d. Assign the geokeys, sort the data by gps time and zip the data to database and to S3 AWS.
Process Date/Time: 2024-03-07 00:00:00
Process Contact: Office for Coastal Management (OCM)

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2023 AK DGGS Lidar DEM: Wrangell Island, AK

Catalog Details

Catalog Item ID: 72046
GUID: gov.noaa.nmfs.inport:72046
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2024-02-01 20:34+0000
Metadata Record Last Modified By: Rebecca Mataosky
Metadata Record Last Modified: 2024-03-07 15:39+0000
Metadata Record Published: 2024-02-05
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2024-02-05
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2025-02-05