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Summary

Short Citation
OCM Partners, 2025: 2016 - 2017 FEMA Lidar: Southwest Virginia & Northeast West Virginia, https://www.fisheries.noaa.gov/inport/item/74963.
Full Citation Examples

Abstract

Virginia (VA_FEMA_R3_Southwest _A and VA_FEMA_R3_Southwest_B)

Leading Edge Geomatics (LEG) collected 6069.91 square miles in the Virginia counties of Bland, Buchanan, Craig (partial), Dickenson, Giles, Grayson, Lee, Russell, Scott, Smyth, Tazewell, Washington, Wise and Wythe, as well as the cities of Bristol, Galax and Norton in Virginia and the city of Bluefield in West Virginia. The nominal pulse spacing for this project was 1 point every 0.7 meters. Dewberry used proprietary procedures to classify the LAS according to project specifications: 1-Unclassified, 2-Ground, 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17- Bridges, 18-High Noise. Dewberry produced 3D breaklines and combined these with the final lidar data to produce seamless hydro flattened DEMs for the project area. The data was formatted according to the client provided tile naming convention with each tile covering an area of 1,500 meters by 1,500 meters. A total of 7,349 tiles were produced for the Virginia Southwest AOI.

West Virginia (VA_FEMA_R3_Northeast)

Axis Geospatial, LLC (Axis) collected 2,640 square miles in the West Virginia counties of Mineral, Hampshire, Grant, Hardy and Pendleton. The nominal pulse spacing for this project was 1 point every 0.7 meters. Dewberry used proprietary procedures to classify the LAS according to project specifications: 0-Never Classified, 1-Unclassified, 2-Ground, 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17- Bridges, 18-High Noise. Dewberry produced 3D breaklines and combined these with the final lidar data to produce seamless hydro flattened DEMs for the project area. The data was formatted according to the client provided tile naming convention with each tile covering an area of 1,500 meters by 1,500 meters. A total of 3,242 tiles were produced for the West Virginia Northeast AOI.

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

Distribution Information

  • Format: 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, UTM 17N NAD83(2011) meters coordinates and elevations in NAVD88 (Geoid12B) meters.

  • LAS/LAZ - LASer

    Bulk download of data files in LAZ format, UTM 17N NAD83(2011) meters coordinates and elevations in NAVD88 (Geoid12B) meters.

  • LAS/LAZ - LASer

    Bulk download of data files in LAZ format, UTM 17N NAD83(2011) meters coordinates and elevations in NAVD88 (Geoid12B) meters.

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

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

Geographic Area 1

-83.708724° W, -80.182698° E, 37.542897° N, 36.528354° S

Southwest Virginia (VA_FEMA_R3_Southwest_A and VA_FEMA_R3_Southwest_B)

Time Frame 1
2016-11-03 - 2017-04-17

Dates of collection for Southwest Virginia (VA_FEMA_R3_Southwest_A and VA_FEMA_R3_Southwest_B)

Item Identification

Title: 2016 - 2017 FEMA Lidar: Southwest Virginia & Northeast West Virginia
Short Name: va2016_va_wv_m10279_metadata
Status: Completed
Creation Date: 2016
Publication Date: 2018
Abstract:

Virginia (VA_FEMA_R3_Southwest _A and VA_FEMA_R3_Southwest_B)

Leading Edge Geomatics (LEG) collected 6069.91 square miles in the Virginia counties of Bland, Buchanan, Craig (partial), Dickenson, Giles, Grayson, Lee, Russell, Scott, Smyth, Tazewell, Washington, Wise and Wythe, as well as the cities of Bristol, Galax and Norton in Virginia and the city of Bluefield in West Virginia. The nominal pulse spacing for this project was 1 point every 0.7 meters. Dewberry used proprietary procedures to classify the LAS according to project specifications: 1-Unclassified, 2-Ground, 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17- Bridges, 18-High Noise. Dewberry produced 3D breaklines and combined these with the final lidar data to produce seamless hydro flattened DEMs for the project area. The data was formatted according to the client provided tile naming convention with each tile covering an area of 1,500 meters by 1,500 meters. A total of 7,349 tiles were produced for the Virginia Southwest AOI.

West Virginia (VA_FEMA_R3_Northeast)

Axis Geospatial, LLC (Axis) collected 2,640 square miles in the West Virginia counties of Mineral, Hampshire, Grant, Hardy and Pendleton. The nominal pulse spacing for this project was 1 point every 0.7 meters. Dewberry used proprietary procedures to classify the LAS according to project specifications: 0-Never Classified, 1-Unclassified, 2-Ground, 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17- Bridges, 18-High Noise. Dewberry produced 3D breaklines and combined these with the final lidar data to produce seamless hydro flattened DEMs for the project area. The data was formatted according to the client provided tile naming convention with each tile covering an area of 1,500 meters by 1,500 meters. A total of 3,242 tiles were produced for the West Virginia Northeast AOI.

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

Purpose:

The purpose of this lidar data was to produce high accuracy 3D elevation products, including tiled lidar in LAS 1.4 format, 3D breaklines, and 1 meter cell size hydro flattened Digital Elevation Models (DEMs). All products follow and comply with USGS Lidar Base Specification Version 1.2.

Supplemental Information:

A complete description of this dataset is available in the Final Project Report that was submitted to the U.S. Geological Survey.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Lidar Base Specification V1.2",

"ldrsens" : "Riegl 780",

"ldrmaxnr" : "infinite",

"ldrnps" : "0.76",

"ldrdens" : "1.746",

"ldranps" : "0.536",

"ldradens" : "3.48",

"ldrfltht" : "1800",

"ldrfltsp" : "100",

"ldrscana" : "60",

"ldrscanr" : "68",

"ldrpulsr" : "280",

"ldrpulsd" : "5",

"ldrpulsw" : "1.5",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.25",

"ldrswatw" : "1996",

"ldrswato" : "55",

"ldrcrs" : "NAD 1983 (2011) UTM Zone 17 Meters",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.125",

"rawnvan" : "115",

"clsnva" : "0.122",

"clsnvan" : "116",

"clsvva" : "0.208",

"clsvvan" : "83"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld points were identified in these files using the standard LAS Withheld bit",

"lasolap" : "Swath overage points were identified in these files using the standard LAS overlap bit",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth, ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored ground due to breakline proximity"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High noise"

}

}}

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN 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 > VIRGINIA
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > WEST VIRGINIA
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: As Needed
Data Presentation Form: Model (digital)
Distribution Liability:

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: U.S. Geological Survey

Support Roles

Data Steward

CC ID: 1371690
Date Effective From: 2025
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: 1371689
Date Effective From: 2025
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: 1371730
Date Effective From: 2018
Date Effective To:
Contact (Organization): U.S. Geological Survey
Address: 12201 Sunrise Valley Drive
Reston, VA 20191
USA
URL: USGS Home

Metadata Contact

CC ID: 1371691
Date Effective From: 2025
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: 1371692
Date Effective From: 2025
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: 1371695
W° Bound: -83.708724
E° Bound: -80.182698
N° Bound: 37.542897
S° Bound: 36.528354
Description

Southwest Virginia (VA_FEMA_R3_Southwest_A and VA_FEMA_R3_Southwest_B)

Extent Group 1 / Time Frame 1

CC ID: 1371694
Time Frame Type: Range
Start: 2016-11-03
End: 2017-04-17
Description:

Dates of collection for Southwest Virginia (VA_FEMA_R3_Southwest_A and VA_FEMA_R3_Southwest_B)

Extent Group 2

Extent Group 2 / Geographic Area 1

CC ID: 1371732
W° Bound: -79.654337
E° Bound: -78.327515
N° Bound: 39.641471
S° Bound: 38.393677
Description

Northeast West Virginia (VA_FEMA_R3_Northeast)

Extent Group 2 / Time Frame 1

CC ID: 1371733
Time Frame Type: Range
Start: 2017-03-23
End: 2017-04-27
Description:

Dates of collection for Northeast West Virginia (VA_FEMA_R3_Northeast)

Spatial Information

Spatial Resolution

Horizontal Distance: 0.4 Meter

Spatial Representation

Representations Used

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

Reference Systems

Reference System 1

CC ID: 1371734

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:3857
EPSG Name: WGS 84 / Pseudo-Mercator
See Full Coordinate Reference System Information

Reference System 2

CC ID: 1371735

Coordinate Reference System

CRS Type: Vertical
EPSG Code: EPSG:5703
EPSG Name: NAVD88 height
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: 1371696
Start Date: 2025-02-26
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=10279/details/10279
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2025 - 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: 1371697
Start Date: 2018
End Date: Present
Download URL: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_VA_FEMA_R3_Northeast_2016_LAS_2018/laz/
Distributor: U.S. Geological Survey (2018 - Present)
File Name: Bulk Download - VA_FEMA_R3_Northeast
Description:

Bulk download of data files in LAZ format, UTM 17N NAD83(2011) meters coordinates and elevations in NAVD88 (Geoid12B) meters.

Distribution Format: LAS/LAZ - LASer
Compression: LAZ

Distribution 3

CC ID: 1371736
Start Date: 2018
End Date: Present
Download URL: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_VA_FEMA_R3_Southwest_A_2016_LAS_2018/laz/
Distributor: U.S. Geological Survey (2018 - Present)
File Name: Bulk Download - VA_FEMA_R3_Southwest_A
Description:

Bulk download of data files in LAZ format, UTM 17N NAD83(2011) meters coordinates and elevations in NAVD88 (Geoid12B) meters.

Distribution Format: LAS/LAZ - LASer
Compression: LAZ

Distribution 4

CC ID: 1371737
Start Date: 2018
End Date: Present
Download URL: https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_VA_FEMA_R3_Southwest_B_2016_LAS_2018/laz/
Distributor: U.S. Geological Survey (2018 - Present)
File Name: Bulk Download - VA_FEMA_R3_Southwest_B
Description:

Bulk download of data files in LAZ format, UTM 17N NAD83(2011) meters coordinates and elevations in NAVD88 (Geoid12B) meters.

Distribution Format: LAS/LAZ - LASer
Compression: LAZ

URLs

URL 1

CC ID: 1371687
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: 1371738
URL: https://prd-tnm.s3.amazonaws.com/StagedProducts/Elevation/metadata/VA__FEMA_R3_SW_Lidar_2016_D16/VA_FEMA_R3_Southwest_A_2016/reports/Virginia_Southwest_Lidar_Project_Report.pdf
Name: Lidar Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to the lidar report

URL 3

CC ID: 1371739
URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Northeast_2016_LAS_2018/ept.json
Name: USGS Entwine Point Tile (EPT) - VA_FEMA_R3_Northeast
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 4

CC ID: 1371740
URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Southwest_A_2016_LAS_2018/ept.json
Name: USGS Entwine Point Tile (EPT) - VA_FEMA_R3_Southwest_A
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: 1371741
URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Southwest_B_2016_LAS_2018/ept.json
Name: USGS Entwine Point Tile (EPT) - VA_FEMA_R3_Southwest_B
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 7

CC ID: 1371749
URL: https://prd-tnm.s3.amazonaws.com/StagedProducts/Elevation/metadata/VA__FEMA_R3_SW_Lidar_2016_D16/VA_FEMA_R3_Southwest_A_2016/reports/Appendix%20D%20-%20Final_Vertical_Accuracy_Report_SVA_FEMA_R3_SW_Lidar_2016_D16.pdf
Name: Vertical Accuracy Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to the vertical accuracy report.

URL 8

CC ID: 1371750
URL: https://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Elevation/metadata/VA__FEMA_R3_SW_Lidar_2016_D16/
Name: USGS Additional Info
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to the reports, breaklines, metadata, and spatial metadata.

Technical Environment

Description:

Microsoft Windows 7 Enterprise Service Pack 1; ESRI ArcCatalog 10.3

Data Quality

Horizontal Positional Accuracy:

Virginia (VA_FEMA_R3_Southwest _A and VA_FEMA_R3_Southwest_B)

Lidar vendors calibrate their lidar systems during installation of the system and then again for every project acquired. Typical calibrations include cross flights that capture features from multiple directions that allow adjustments to be performed so that the captured features are consistent between all swaths and cross flights from all directions. Thirty eight (38) checkpoints were used for horizontal accuracy testing. This dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 41 cm RMSEx/RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 1 meter at a 95% confidence level. Actual positional accuracy of this dataset was found to be RMSEx = 23.7 cm and RMSEy = 20.8 cm which equates to +/- 54.6 cm at 95% confidence level or 31.6 cm RMSEr.

West Virginia (VA_FEMA_R3_Northeast)

Lidar vendors calibrate their lidar systems during installation of the system and then again for every project acquired. Typical calibrations include cross flights that capture features from multiple directions that allow adjustments to be performed so that the captured features are consistent between all swaths and cross flights from all directions. Twenty Five (25) checkpoints were used for horizontal accuracy testing. This dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 41 cm RMSEx/RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 1 meter at a 95% confidence level. Actual positional accuracy of this dataset was found to be RMSEx = 34.1 cm and RMSEy = 15.1 cm which equates to +/- 64.5 cm at 95% confidence level or 37.2 cm RMSEr.

Vertical Positional Accuracy:

Virginia (VA_FEMA_R3_Southwest _A and VA_FEMA_R3_Southwest_B)

The vertical accuracy of the lidar was tested by Dewberry with 199 independent survey checkpoints. The survey checkpoints are evenly distributed throughout the project area and are located in areas of non-vegetated terrain, including bare earth, open terrain, and urban terrain (116), and vegetated terrain, including forest, brush, tall weeds, crops, and high grass (83). The vertical accuracy is tested by comparing survey checkpoints to a triangulated irregular network (TIN) that is created from the lidar ground points. Checkpoints are always compared to interpolated surfaces created from the lidar point cloud because it is unlikely that a survey checkpoint will be located at the location of a discrete lidar point. All checkpoints located in non-vegetated terrain were used to compute the Non-vegetated Vertical Accuracy (NVA). Project specifications required a NVA of 19.6 cm at the 95% confidence level based on RMSEz (10 cm) x 1.9600. All checkpoints located in vegetated terrain were used to compute the Vegetated Vertical Accuracy (VVA). Project specifications required a VVA of 29.4 cm based on the 95th percentile.

The lidar dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10 cm RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz = 6.2 cm, equating to +/- 12.2 cm at 95% confidence level. Actual VVA accuracy was found to be +/- 20.8 cm at the 95th percentile. The 5% outliers consisted of 4 checkpoints that are larger than the 95th percentile. These checkpoints have DZ values ranging between -36.3 cm and 43.0 cm.

West Virginia (VA_FEMA_R3_Northeast)

The vertical accuracy of the lidar was tested by Dewberry with 109 independent survey checkpoints. The survey checkpoints are evenly distributed throughout the project area and are located in areas of non-vegetated terrain, including bare earth, open terrain, and urban terrain (64), and vegetated terrain, including forest, brush, tall weeds, crops, and high grass (45). The vertical accuracy is tested by comparing survey checkpoints to a triangulated irregular network (TIN) that is created from the lidar ground points. Checkpoints are always compared to interpolated surfaces created from the lidar point cloud because it is unlikely that a survey checkpoint will be located at the location of a discrete lidar point. All checkpoints located in non-vegetated terrain were used to compute the Non-vegetated Vertical Accuracy (NVA). Project specifications required a NVA of 19.6 cm at the 95% confidence level based on RMSEz (10 cm) x 1.9600. All checkpoints located in vegetated terrain were used to compute the Vegetated Vertical Accuracy (VVA). Project specifications required a VVA of 29.4 cm based on the 95th percentile.

The lidar dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10 cm RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz = 6.2 cm, equating to +/- 12.2 cm at 95% confidence level. Actual VVA accuracy was found to be +/- 13.3 cm at the 95th percentile. The 5% outliers consisted of 2 checkpoints that are larger than the 95th percentile. These checkpoints have DZ values ranging between 16.2 cm and 20.1 cm.

Completeness Report:

A visual qualitative assessment was performed to ensure data completeness and bare earth data cleanliness. No void or missing data and data passes vertical accuracy specifications.

Conceptual Consistency:

Data covers the project boundary.

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:

The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tiles (EPT) hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.

Sources

USGS AWS Entwine Point Tile (EPT) - VA_FEMA_R3_Northeast

CC ID: 1371743
Contact Role Type: Publisher
Contact Type: Organization
Contact Name: USGS
Citation URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Northeast_2016_LAS_2018/ept.json
Citation URL Name: USGS AWS Entwine Point Tile (EPT) for VA_FEMA_R3_Northeast

USGS AWS Entwine Point Tile (EPT) - VA_FEMA_R3_Southwest_A

CC ID: 1371744
Contact Role Type: Publisher
Contact Type: Organization
Contact Name: USGS
Citation URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Southwest_A_2016_LAS_2018/ept.json
Citation URL Name: USGS AWS Entwine Point Tile (EPT) for VA_FEMA_R3_Southwest_A

USGS AWS Entwine Point Tile (EPT) - VA_FEMA_R3_Southwest_B

CC ID: 1371745
Contact Role Type: Publisher
Contact Type: Organization
Contact Name: USGS
Citation URL: https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Southwest_B_2016_LAS_2018/ept.json
Citation URL Name: USGS AWS Entwine Point Tile (EPT) for VA_FEMA_R3_Southwest_B

Process Steps

Process Step 1

CC ID: 1371681
Description:

Data for the Virginia portion of the VA FEMA Lidar project was acquired by Leading Edge Geomatics (LEG).

The project area included approximately 6069.91 contiguous square miles or 15720.99 square kilometers for a portion of Virginia. Leading Edge Geomatics, LLC operated a Piper Navajo C-GKCN outfitted with a Riegl 780 dual channel laser scanner lidar system . The data was delivered in the UTM coordinate system, meters, zone 17, horizontal datum NAD83 (2011), vertical datum NAVD88, Geoid 12B. Deliverables for the project included a raw (unclassified) calibrated lidar point cloud, survey control, and a final acquisition/calibration report.

The calibration process considered all errors inherent with the equipment including errors in GPS, IMU, and sensor specific parameters. Adjustments were made to achieve a flight line to flight line data match (relative calibration) and subsequently adjusted to control for absolute accuracy. Process steps to achieve this are as follows:

Rigorous lidar calibration: all sources of error such as the sensor's ranging and torsion parameters, atmospheric variables, GPS conditions, and IMU offsets were analyzed and removed to the highest level possible. This method addresses all errors, both vertical and horizontal in nature. Ranging, atmospheric variables, and GPS conditions affect the vertical position of the surface, whereas IMU offsets and torsion parameters affect the data horizontally. The horizontal accuracy is proven through repeatability: when the position of features remains constant no matter what direction the plane was flying and no matter where the feature is positioned within the swath, relative horizontal accuracy is achieved.

Absolute horizontal accuracy is achieved through the use of differential GPS with base lines shorter than 25 miles. The base station is set at a temporary monument that is 'tied-in' to the CORS network. The same position is used for every lift, ensuring that any errors in its position will affect all data equally and can therefore be removed equally.

Vertical accuracy is achieved through the adjustment to ground control survey points within the finished product. Although the base station has absolute vertical accuracy, adjustments to sensor parameters introduces vertical error that must be normalized in the final (mean) adjustment.

The withheld and overlap bits are set and all headers, appropriate point data records, and variable length records, including spatial reference information, are updated in GeoCue software and then verified using proprietary Dewberry tools.

Process Date/Time: 2016-12-01 00:00:00

Process Step 2

CC ID: 1371746
Description:

Data for the West Virginia portion of the VA FEMA Lidar project was acquired by Axis Geospatial, LLC (Axis).

The project area included approximately 2,640 contiguous square miles or 6,837 square kilometers for a portion of West Virginia. Axis Geospatial, LLC operated a Cessna 206H single engine aircraft (N223TC) outfitted with a Riegl LMS-Q1560 dual channel laser scanner lidar system . The data was delivered in the UTM coordinate system, meters, zone 17, horizontal datum NAD83 (2011), vertical datum NAVD88, Geoid 12B. Deliverables for the project included a raw (unclassified) calibrated lidar point cloud, survey control, and a final acquisition/calibration report.

The calibration process considered all errors inherent with the equipment including errors in GPS, IMU, and sensor specific parameters. Adjustments were made to achieve a flight line to flight line data match (relative calibration) and subsequently adjusted to control for absolute accuracy. Process steps to achieve this are as follows:

Rigorous lidar calibration: all sources of error such as the sensor's ranging and torsion parameters, atmospheric variables, GPS conditions, and IMU offsets were analyzed and removed to the highest level possible. This method addresses all errors, both vertical and horizontal in nature. Ranging, atmospheric variables, and GPS conditions affect the vertical position of the surface, whereas IMU offsets and torsion parameters affect the data horizontally. The horizontal accuracy is proven through repeatability: when the position of features remains constant no matter what direction the plane was flying and no matter where the feature is positioned within the swath, relative horizontal accuracy is achieved.

Absolute horizontal accuracy is achieved through the use of differential GPS with base lines shorter than 25 miles. The base station is set at a temporary monument that is 'tied-in' to the CORS network. The same position is used for every lift, ensuring that any errors in its position will affect all data equally and can therefore be removed equally.

Vertical accuracy is achieved through the adjustment to ground control survey points within the finished product. Although the base station has absolute vertical accuracy, adjustments to sensor parameters introduces vertical error that must be normalized in the final (mean) adjustment.

The withheld and overlap bits are set and all headers, appropriate point data records, and variable length records, including spatial reference information, are updated in GeoCue software and then verified using proprietary Dewberry tools.

Process Date/Time: 2017-04-01 00:00:00

Process Step 3

CC ID: 1371682
Description:

Dewberry utilizes a variety of software suites for inventory management, classification, and data processing. All lidar related processes begin by importing the data into the GeoCue task management software. The swath data is tiled according to project specifications (1,500 m x 1,500 m). The tiled data is then opened in Terrascan where Dewberry classifies edge of flight line points that may be geometrically unusable with the withheld bit. These points are separated from the main point cloud so that they are not used in the ground algorithms. Overage points are then identified with the overlap bit. Dewberry then uses proprietary ground classification routines to remove any non-ground points and generate an accurate ground surface. The ground routine consists of three main parameters (building size, iteration angle, and iteration distance); by adjusting these parameters and running several iterations of this routine an initial ground surface is developed. The building size parameter sets a roaming window size. Each tile is loaded with neighboring points from adjacent tiles and the routine classifies the data section by section based on this roaming window size. The second most important parameter is the maximum terrain angle, which sets the highest allowed terrain angle within the model. As part of the ground routine, low noise points are classified to class 7 and high noise points are classified to class 18. Once the ground routine has been completed, bridge decks are classified to class 17 using bridge breaklines compiled by Dewberry. A manual quality control routine is then performed using hillshades, cross-sections, and profiles within the Terrasolid software suite. After this QC step, a peer review is performed on all tiles and a supervisor manual inspection is completed on a percentage of the classified tiles based on the project size and variability of the terrain. After the ground classification and bridge deck corrections are completed, the dataset is processed through a water classification routine that utilizes breaklines compiled by Dewberry to automatically classify hydrographic features. The water classification routine selects ground points within the breakline polygons and automatically classifies them as class 9, water. During this water classification routine, points that are within 1x NPS or less of the hydrographic features are moved to class 10, an ignored ground due to breakline proximity. A final QC is performed on the data. All headers, appropriate point data records, and variable length records, including spatial reference information, are updated in GeoCue software and then verified using proprietary Dewberry tools.

The data was classified as follows:

Class 1 = Unclassified. This class includes vegetation, buildings, noise etc.

Class 2 = Ground

Class 7= Low Noise

Class 9 = Water

Class 10 = Ignored Ground due to breakline proximity

Class 17 = Bridge Decks

Class 18 = High Noise

The LAS header information was verified to contain the following:

Class (Integer)

Adjusted GPS Time (0.0001 seconds)

Easting (0.003 m)

Northing (0.003 m)

Elevation (0.003 m)

Echo Number (Integer)

Echo (Integer)

Intensity (16 bit integer)

Flight Line (Integer)

Scan Angle (degree)

Process Date/Time: 2017-01-01 00:00:00

Process Step 4

CC ID: 1371747
Description:

Original point clouds in LAS/LAZ format were restructured as Entwine Point Tiles and stored on Amazon Web Services. The data were re-projected horizontally to WGS84 web mercator (EPSG 3857) and the vertical units of NAVD88 (Geoid12B) meters were retained.

Process Contact: U.S. Geological Survey

Process Step 5

CC ID: 1371748
Description:

The NOAA Office for Coastal Management (OCM) created references to the Entwine Point Tiles (EPT) that were ingested into the NOAA Digital Coast Data Access Viewer (DAV). No changes were made to the data. The DAV will access the point cloud as it resides on Amazon Web Services (AWS) under the usgs-lidar-public container.

These are the AWS URLs being accessed:

https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Northeast_2016_LAS_2018/ept.json

https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Southwest_A_2016_LAS_2018/ept.json

https://s3-us-west-2.amazonaws.com/usgs-lidar-public/USGS_LPC_VA_FEMA_R3_Southwest_B_2016_LAS_2018/ept.json

Process Date/Time: 2025-02-26 00:00:00
Process Contact: Office for Coastal Management (OCM)

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2016 - 2017 FEMA Lidar DEM: Southwest Virginia & Northeast West Virginia

Catalog Details

Catalog Item ID: 74963
GUID: gov.noaa.nmfs.inport:74963
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2025-02-26 18:39+0000
Metadata Record Last Modified By: Rebecca Mataosky
Metadata Record Last Modified: 2025-03-03 15:10+0000
Metadata Record Published: 2025-02-26
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2025-02-26
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2026-02-26