2014 FEMA Lidar DEM: Ketchikan, Alaska
Data Set (DS) | OCM Partners (OCMP)GUID: gov.noaa.nmfs.inport:52496 | Updated: January 10, 2024 | Published / External
Summary
Short Citation
OCM Partners, 2024: 2014 FEMA Lidar DEM: Ketchikan, Alaska, https://www.fisheries.noaa.gov/inport/item/52496.
Full Citation Examples
Digital Elevation model, derived from a lidar point cloud data, developed to support FEMA flood risk analysis and mapping in Ketchikan, Alaska. Point cloud is classified as ground (class 2) and other (class 1). The data was collected under a FEMA contract to the Strategic Alliance for Risk Reduction (STARR) with an accuracy requirement to support 2-foot contours. Original tasking indicates additional classes would be populated (7, 9, 10, 11), but they are not in the data set.
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.
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GeoTIFF
Bulk download of data files in the original coordinate system in horizontal meters and feet. Vertical units are meters.
None
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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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
https://coast.noaa.gov
Metadata Contact
NOAA Office for Coastal Management (NOAA/OCM)
coastal.info@noaa.gov
(843) 740-1202
https://coast.noaa.gov
Extents
-131.890301° W,
-131.454155° E,
55.517998° N,
55.290125° S
2014-11-30
Item Identification
Title: | 2014 FEMA Lidar DEM: Ketchikan, Alaska |
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Short Name: | 2014 Ketchikan, Alaska |
Status: | Completed |
Publication Date: | 2014-11-30 |
Abstract: |
Digital Elevation model, derived from a lidar point cloud data, developed to support FEMA flood risk analysis and mapping in Ketchikan, Alaska. Point cloud is classified as ground (class 2) and other (class 1). The data was collected under a FEMA contract to the Strategic Alliance for Risk Reduction (STARR) with an accuracy requirement to support 2-foot contours. Original tasking indicates additional classes would be populated (7, 9, 10, 11), but they are not in the data set. |
Purpose: |
Terrain data are used to represent the topography of a watershed and/or floodplain environment and to extract useful information for hydraulic and hydrologic models. (Source: FEMA Guidelines and Standards for Flood Risk Analysis and Mapping.) |
Keywords
Theme Keywords
Thesaurus | Keyword |
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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
|
UNCONTROLLED | |
FEMA NFIP Topic Category | Bare Earth |
FEMA NFIP Topic Category | Breaklines |
FEMA NFIP Topic Category | Contours |
FEMA NFIP Topic Category | DEM |
FEMA NFIP Topic Category | Digital Elevation Model |
FEMA NFIP Topic Category | Elevation Data |
FEMA NFIP Topic Category | Flow Vectors |
FEMA NFIP Topic Category | Hydro Enforced DEM |
FEMA NFIP Topic Category | Land Surface |
FEMA NFIP Topic Category | LIDAR |
FEMA NFIP Topic Category | Relief |
FEMA NFIP Topic Category | Slope |
FEMA NFIP Topic Category | TIN |
FEMA NFIP Topic Category | Topography |
FEMA NFIP Topic Category | Triangulated Irregular Network |
Spatial Keywords
Thesaurus | Keyword |
---|---|
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 |
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Global Change Master Directory (GCMD) Instrument Keywords |
LIDAR > Light Detection and Ranging
|
Platform Keywords
Thesaurus | Keyword |
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Global Change Master Directory (GCMD) Platform Keywords |
Airplane > Airplane
|
Physical Location
Organization: | Office for Coastal Management |
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City: | Charleston |
State/Province: | SC |
Data Set Information
Data Set Scope Code: | Data Set |
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Data Set Type: | Elevation |
Maintenance Frequency: | Unknown |
Data Presentation Form: | FEMA-DCS-Terrain |
Entity Attribute Detail Citation: |
FEMA's Guidelines and Standards for Flood Risk Analysis and Mapping contains a detailed description of the data themes and references to other relevant information. |
Distribution Liability: |
No warranty expressed or implied is made by FEMA regarding the utility of the data on any other system nor shall the act of distribution constitute any such warranty. 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: | Federal Emergency Management Agency |
Support Roles
Data Steward
Date Effective From: | 2018-05-01 |
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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
Date Effective From: | 2018-05-01 |
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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
Date Effective From: | 2018-05-01 |
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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
Date Effective From: | 2018-05-01 |
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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 |
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Extent Group 1
Extent Group 1 / Geographic Area 1
W° Bound: | -131.890301 | |
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E° Bound: | -131.454155 | |
N° Bound: | 55.517998 | |
S° Bound: | 55.290125 |
Extent Group 1 / Time Frame 1
Time Frame Type: | Discrete |
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Start: | 2014-11-30 |
Spatial Information
Spatial Resolution
Horizontal Distance: | 3.0 Foot |
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Access Information
Security Class: | Unclassified |
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Data Access Procedure: |
Data is available online for 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
Start Date: | 2018-05-01 |
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End Date: | Present |
Download URL: | https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8522 |
Distributor: | NOAA Office for Coastal Management (NOAA/OCM) (2018-05-01 - 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. |
Compression: | Zip |
Distribution 2
Start Date: | 2018-05-01 |
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End Date: | Present |
Download URL: | https://noaa-nos-coastal-lidar-pds.s3.us-east-1.amazonaws.com/dem/AK_Ketchikan_FEMA_DEM_2014_8522/index.html |
Distributor: | NOAA Office for Coastal Management (NOAA/OCM) (2018-05-01 - Present) |
File Name: | Bulk Download |
Description: |
Bulk download of data files in the original coordinate system in horizontal meters and feet. Vertical units are meters. |
File Type (Deprecated): | GeoTIFF |
Distribution Format: | GeoTIFF |
URLs
URL 1
URL: | https://coast.noaa.gov/ |
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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
URL: | https://coast.noaa.gov/dataviewer/ |
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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
URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8521/supplemental/ketchikan_extent_2014_m8521.kmz |
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Name: | Browse graphic |
URL Type: |
Browse Graphic
|
File Resource Format: | KML |
Description: |
This graphic displays the footprint for this lidar data set. |
URL 4
URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8521/supplemental/02130C_Elevation_Data_QA_Report_for_Ketchikan_Alaska.pdf |
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Name: | Dataset report |
URL Type: |
Online Resource
|
File Resource Format: | |
Description: |
Link to data set QA report. |
URL 5
URL: | https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/8521/supplemental/02130C_Ketchikan_FEMA_M-11_Certificate_of_Compliance.pdf |
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Name: | Certificate of compliance |
URL Type: |
Online Resource
|
File Resource Format: | |
Description: |
FEMA certificate of compliance |
Technical Environment
Description: |
Original data development environment may vary. Finishing of the data is done using Esri’s ArcGIS software. The submitted file geodatabase was created using ArcGIS version 10.0. |
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Data Quality
Horizontal Positional Accuracy: |
The LiDAR data horizontal accuracy is in compliance with the National Standard for Spatial Data Accuracy (NSSDA) RMSE estimation of elevation data in support of 2ft. contour mapping products as it is referenced in the FEMA Guidelines and Standards for Flood Risk Analysis and Mapping. |
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Vertical Positional Accuracy: |
Deliverables were tested by for both vertical and horizontal accuracy. The vertical unit of the data file is in meters with 2-decimal point precision. ASPRS, USGS, and FEMA vertical accuracy requirements were used to test lidar dataset. Fundamental Vertical Accuracy (FVA) tested against survey data points measured 0.0513 meters at 95% confidence and and RMSE of 0.0496 RMSE. The errors were not normally distributed. See the QA report for more details. |
Completeness Report: |
The bare earth surface data is an estimation of the bare earth surface and does not include vegetative and built features. Likewise, it contains estimates of water edges at the time of data collection, and may not reflect current conditions. The bare earth surface will contain voids where insufficient energy was reflected from the surface to generate a valid return from the terrain. Voids in the bare earth surface tend to occur in heavily vegetated areas, water bodies, and beneath buildings, motor vehicles, bridges etc. Fresh or wet asphalt, wet sand and certain types of vegetation can also cause voids or anomalous elevations. The data may have been further processed to remove points found to be within delineated water bodies. Low confidence areas are delineated and provided in a separate dataset. |
Conceptual Consistency: |
Checks were performed to ensure the data files can be opened, are georeferenced properly, and cover the geographic area completely. Additionally, field survey checkpoints are obtained to evaluate the accuracy of LiDAR products. A minimum of 100 checkpoints are tested in a project area. At least 20 for 5 different land vegetation categories (forest, built-up, scrub, weeds/crop, and bare-earth/low grass) are tested with forested areas requiring a minimum of 40 checkpoints. A statistical analysis between the difference in elevations of the field survey checkpoints and LiDAR-derived, bare earth elevations at the same locations provides a quality assessment of the LiDAR data. |
Lineage
Sources
Ketchikan 2ft Contours
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
KETCHIKAN, AK 2ft Contours. |
Ketchikan 3ft Digital Elevation Models
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
KETCHIKAN, AK 3ft Bare Earth Digital Elevation Models. |
Ketchikan Collection Area, Flight Lines, LiDAR Swath Index and LiDAR Tile Index
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
KETCHIKAN, AK LiDAR Acquisition vector data. |
Ketchikan Ground Control Survey
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
KETCHIKAN, AK LiDAR Acquisition ground control survey. |
Ketchikan Ketchikan Classified Tiled Point Cloud
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
KETCHIKAN, AK LiDAR Acquisition Classified LAS Bare Earth point cloud data. |
Ketchikan Ketchikan Unclassified Swath Point Cloud
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
KETCHIKAN, AK LiDAR Acquisition Unclassified LAS raw point cloud data. |
Ketchikan LiDAR Quality Assurance Report
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
Quality Assurace Report for LiDAR and derivative products part of the Technical Support Data Notebook that contains complete narrative on the acquisition and processing of the LiDAR dataset, including area diagram, reports, metadata and other supporting documentation. |
Ketchikan Pre-Flight Planning Report and Post Flight Report
Publish Date: | 2014-12-31 |
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Extent Type: | Discrete |
Extent Start Date/Time: | 2014-12-31 |
Source Contribution: |
KETCHIKAN, AK LiDAR Acquisition Documentation. |
Process Steps
Process Step 1
Description: |
Terrain data used for flood risk analysis go through LiDAR preliminary processing and the unclassified point cloud data are tested as specified in the USGS National Geospatial Program Base LiDAR Specification Version 1.0. Where the Mapping Activity Statement (MAS) requires bare earth post-processing of the floodplain area of interest (AOI), the elevation data are tested and comply with both the Fundamental Vertical Accuracy (FVA) and Consolidated Vertical Accuracy (CVA) requirements. Where no bare earth post-processing is specified, only the FVA requirements apply for LiDAR preliminary processing. |
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Process Date/Time: | 2014-09-30 00:00:00 |
Process Step 2
Description: |
Ground Survey: RTK GPS based surveys were utilized to support both processing and testing of LiDAR data within FEMA designated Areas of Interest (AOIs). Geographically distinct ground points were surveyed using GPS technology throughout the AOIs to provide support for three distinct tasks. Task 1: Ground control monuments utilized for the STARR Ketchikan LiDAR dataset. Ground control monuments are used to provide redundant control within 13 nautical miles of mission areas for LiDAR flights, as well as the collection of ground control points using real-time kinematic (RTK) survey techniques. The horizontal datum for this dataset is NAD83 (2011), the vertical datum is NAVD88, Geoid 12A, and the data is projected in Alaska State Plane Zone 1. Units are in US Survey Feet. Task 2: RTK (real time kinematic) ground control points collected for the STARR Ketchikan LiDAR dataset. RTK ground control points are used to correct and verify the vertical accuracy of the LiDAR data. The horizontal datum for this dataset is NAD83 (2011), the vertical datum is NAVD88, Geoid 12A, and the data is projected in Alaska State Plane Zone 1. Units are in US Survey Feet. Task 3: Land cover class ground check points collected for the STARR Ketchikan LiDAR dataset. Land class ground check points are used to assess the vertical accuracy of the LiDAR data and are collected using real time kinematic (RTK) survey techniques. The horizontal datum for this dataset is NAD83 (2011), the vertical datum is NAVD88, Geoid 12A, and the data is projected in Alaska State Plane Zone 1. Units are in US Survey Feet. |
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Process Date/Time: | 2014-07-01 00:00:00 |
Process Step 3
Description: |
LiDAR Acquisition: General: LiDAR collection was collected using a Leica ALS70 system mounted in a Piper Navajo airplane. Yielded an average pulse density of >= 4 pulses/square meter over the Ketchikan Project Area. Swath Acquisition: This swath dataset represents the STARR Ketchikan LiDAR study area. This data is delineated in 4800x4800 ft tiles. Tile naming is derived from the 4 four digits of the easting and first four digits of the northing coordinates of the lower left corner. Data is unclassified (class 0). The horizontal datum for this dataset is NAD83 (2011), the vertical datum is NAVD88, Geoid 12A, and it is projected in Alaska State Plane Zone 1. Units are in US Survey Feet. Quantum Spatial collected the STARR Ketchikan LiDAR data for STARR on 07/12/2014 and 07/13/2014 further information is available in the Ketchikan Post-Flight Aerial Acquisition Report. All areas were surveyed with an opposing flight line side-lap of >=50% (=100% overlap) in order to reduce laser shadowing and increase surface laser painting. To accurately solve for laser point position (geographic coordinates x, y and z), the positional coordinates of the airborne sensor and the attitude of the aircraft were recorded continuously throughout the LiDAR data collection mission. Position of the aircraft was measured twice per second (2 Hz) by an onboard differential GPS unit, and aircraft attitude was measured 200 times per second (200 Hz) as pitch, roll and yaw (heading) from an onboard inertial measurement unit (IMU). All swath data were classified as Class 0 or Unclassified. Leica ALS70 Instrument Parameters: Beam diameter: 37 cm cm, Pulse rate: 175 kHz, Maximum returns: 4, Speed: 150 knots, Overlap: 60 %, Laser power: 93.6 %, Field of view (FOV): 30 degrees, Beam wavelength: 1064 nm, Frequency of GPS sampling: 2 Hz, Frequency of IMU sampling: 200 Hz, Swath width: 857 m, AGL: 5207 - 5315 MSL m, Average pulse density: 4 |
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Process Date/Time: | 2014-07-13 00:00:00 |
Process Step 4
Description: |
Bare Earth Processing: QSI processing staff initiated a suite of automated and manual techniques to process the data into ASPRS Class 2 Bare Earth. The calibrated and filt ered LiDAR point cloud was hand checked for accuracy. Generate bare earth models as triangulated surfaces. The calibrated and filtered LiDAR point cloud was hand checked for accuracy. All points were placed in one of the following categories: 1 Unclassified, 2 Ground, 7 Noise, and 12 Overlap Points. Model Key points were then generated from the Ground points and placed in Category 8. Requested elevation values were evaluated for the Consolidated Vertical Accuracy (CVA) testing. Ketchikan Classified LiDAR ASPRS Classifications 1 Unclassified 2 Ground |
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Process Date/Time: | 2014-09-30 00:00:00 |
Process Step 5
Description: |
Digital Elevation Model tiles were received in ESRI Arc coverage proprietary format from FEMA. Tiles were in Alaska state plane zone 01 US survey feet with vertical units of US survey feet. The vertical datum was NAVD88 using the NGS Geoid12a geoid model. Data were converted to tif format and changed to horizontal and vertical meters for ingest in the Digital Coast Data Access Viewer. The change of horizontal units was done because the system was not processing the files in US survey feet correctly. This projection does not have an EPSG code. EPSG code 6394 was used for Alaska State Plane Zone 1 NAD83(2011) in meters. Tests showed this data was correctly interpreted in some software, but not all software. The data in both feet and meters is available on the bulk download data access link. |
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Process Date/Time: | 2018-05-01 00:00:00 |
Process Contact: | Office for Coastal Management (OCM) |
Source: | Ketchikan 3ft Digital Elevation Models |
Related Items
Item Type | Relationship Type | Title |
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Data Set (DS) | Cross Reference |
2014 FEMA Lidar: Ketchikan, Alaska Lidar point cloud source for this DEM |
Catalog Details
Catalog Item ID: | 52496 |
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GUID: | gov.noaa.nmfs.inport:52496 |
Metadata Record Created By: | Kirk Waters |
Metadata Record Created: | 2018-05-01 08:22+0000 |
Metadata Record Last Modified By: | Kirk Waters |
Metadata Record Last Modified: | 2024-01-10 19:01+0000 |
Metadata Record Published: | 2024-01-10 |
Owner Org: | OCMP |
Metadata Publication Status: | Published Externally |
Do Not Publish?: | N |
Metadata Last Review Date: | 2022-03-16 |
Metadata Review Frequency: | 1 Year |
Metadata Next Review Date: | 2023-03-16 |