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Item Identification
Keywords
Physical Location
Data Set Info
Support Roles
Extents
Spatial Info
Access Info
Distribution Info
URLs
Data Quality
Lineage
Catalog Details

Summary

Short Citation
OCM Partners, 2024: 2019 AK DGGS Lidar DEM: Mt. Juneau, AK, https://www.fisheries.noaa.gov/inport/item/67999.
Full Citation Examples

Abstract

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 Mount Juneau, 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. Ground control data were collected on September 5, 2019, and aerial lidar were collected on September 6, 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/10.14509/30731).

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.

Distribution Information

  • 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.

  • GeoTIFF

    Bulk download of data files in the original coordinate system.

Access Constraints:

None

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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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.

Controlled Theme Keywords

COASTAL ELEVATION, DIGITAL ELEVATION/TERRAIN MODEL (DEM), EARTH SCIENCE, elevation, geoscientificInformation, 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

-134.478291° W, -134.327115° E, 58.330648° N, 58.299581° S

Time Frame 1
2019-09-06

Item Identification

Title: 2019 AK DGGS Lidar DEM: Mt. Juneau, AK
Short Name: ak2019_mt_juneau_dem_m9608_metadata
Status: Completed
Creation Date: 2019
Publication Date: 2022
Abstract:

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 Mount Juneau, 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. Ground control data were collected on September 5, 2019, and aerial lidar were collected on September 6, 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/10.14509/30731).

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.

Purpose:

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.

Supplemental Information:

>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 7.5 cm and the average density is 15.58 pts/m2.

>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).

>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 50-centimeter 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.

Keywords

Theme Keywords

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

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT
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
UNCONTROLLED
Alaska Division of Geological & Geophysical Surveys Court House Hill
Alaska Division of Geological & Geophysical Surveys Ebner Falls
Alaska Division of Geological & Geophysical Surveys Gastineau Channel
Alaska Division of Geological & Geophysical Surveys Gold Creek
Alaska Division of Geological & Geophysical Surveys Granite Creek
Alaska Division of Geological & Geophysical Surveys Harris Harbor
Alaska Division of Geological & Geophysical Surveys Juneau
Alaska Division of Geological & Geophysical Surveys Mount Juneau
Alaska Division of Geological & Geophysical Surveys Mount Maria
Alaska Division of Geological & Geophysical Surveys Starr Hill

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: These data products were funded by U.S. Geological Survey, Alaska Electric Light & Power Company, and the State of Alaska and collected and processed 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, Katreen Wolken, G.J. Herbst, A.M.

Support Roles

Data Steward

CC ID: 1186822
Date Effective From: 2022
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: 1186821
Date Effective From: 2022
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: 1186823
Date Effective From: 2022
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: 1186824
Date Effective From: 2022
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: 1298586
W° Bound: -134.478291
E° Bound: -134.327115
N° Bound: 58.330648
S° Bound: 58.299581

Extent Group 1 / Time Frame 1

CC ID: 1298585
Time Frame Type: Discrete
Start: 2019-09-06

Spatial Information

Spatial Representation

Representations Used

Grid: Yes

Reference Systems

Reference System 1

CC ID: 1298582

Coordinate Reference System

CRS Type: Vertical
EPSG Code: EPSG:5703
EPSG Name: NAVD88 height
See Full Coordinate Reference System Information

Reference System 2

CC ID: 1298583

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:6337
EPSG Name: NAD83(2011) / UTM zone 8N
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:

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: 1186828
Start Date: 2022-10-07
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9608/details/9608
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Customized Download
Description:

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.

File Type (Deprecated): Zip
Compression: Zip

Distribution 2

CC ID: 1186829
Start Date: 2022-10-07
End Date: Present
Download URL: https://noaa-nos-coastal-lidar-pds.s3.us-east-1.amazonaws.com/dem/AK_Mt_Juneau_DEM_2019_9608/index.html
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in the original coordinate system.

File Type (Deprecated): GeoTIFF
Distribution Format: GeoTIFF

URLs

URL 1

CC ID: 1186819
URL: https://coast.noaa.gov/
Name: NOAA's Office for Coastal Management (OCM) website
URL Type:
Online Resource
File Resource Format: HTML
Description:

Information on the NOAA Office for Coastal Management (OCM)

URL 2

CC ID: 1186820
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 3

CC ID: 1186888
URL: https://dggs.alaska.gov/webpubs/dggs/rdf/text/rdf2021_012.pdf
Name: Lidar Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

This lidar report provides accompanying information about the collection and processing of 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 -19.5 cm between 22 control points and the point cloud. We reduced this offset to +4.4 cm by performing a vertical transformation of the lidar point data. We used six 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 10.8 cm. We evaluated the relative accuracy for this dataset as the interswath overlap consistency and measured it at 8.4 cm RMSE. See the accompanying report for tables of checkpoint comparisons.

Completeness Report:

This data release is complete.

Conceptual Consistency:

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.

Lineage

Lineage Statement:

Data were collected by the Alaska Division of Geological and Geophysical Surveys (AK DGGS). OCM downloaded the data from the Alaska DGGS Elevation Portal and processed the data to be available for custom and bulk download from the NOAA Digital Coast Data Access Viewer (DAV).

Sources

Alaska Division of Geological and Geophysical Surveys (AK DGGS)

CC ID: 1298578
Contact Role Type: Originator
Contact Type: Organization
Contact Name: AK DGGS
Citation URL: https://elevation.alaska.gov/
Citation URL Name: AK DGGS Elevation Portal

Process Steps

Process Step 1

CC ID: 1298579
Description:

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 to survey from an elevation of ~130 m above ground level, at a ground speed of ~30 m/s, and with a scan angle set from 80 to 280 degrees. The total survey area covers ~14 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 second part of the survey, covering Mount Juneau, started at 2:30 pm from Mount Anderson on Douglas Island. The weather throughout the survey was clear with no wind.

Process Date/Time: 2019-09-06 00:00:00

Process Step 2

CC ID: 1298580
Description:

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 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.

Process Date/Time: 2019-01-01 00:00:00

Process Step 3

CC ID: 1298581
Description:

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 0.5 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.

Process Date/Time: 2022-10-11 00:00:00
Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 67999
GUID: gov.noaa.nmfs.inport:67999
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2022-10-07 15:49+0000
Metadata Record Last Modified By: Kirk Waters
Metadata Record Last Modified: 2024-01-10 19:27+0000
Metadata Record Published: 2024-01-10
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-10-07
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-10-07