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Short Citation:
National Geodetic Survey, 2024: 2018-2019 NOAA NGS Topobathy Lidar Post Hurricane Harvey: Galveston to Corpus Christi, TX, https://www.fisheries.noaa.gov/inport/item/63297.

Item Identification

Title: 2018-2019 NOAA NGS Topobathy Lidar Post Hurricane Harvey: Galveston to Corpus Christi, TX
Status: Completed
Publication Date: 2021-01-04
Abstract:

These data were collected by Leading Edge Geomatics using a Leica Chiroptera II Bathymetric & Topographic Sensor. The data were acquired from October 22, 2018 through May 31, 2019. The data include topobathy data in LAS 1.4 format classified as created, unclassified (1); ground (2); noise (low or high) (7); bathymetric bottom (40); water surface (41); derived water surface (42); submerged object (43); IHO S-57 object (44); no bathymetric bottom found (45); and bathymetric bottom temporal changes (46) in accordance with project specifications. The project consists of approximately 942 square miles of data along the Gulf shore of Texas from Galveston to Corpus Christi. This full project delivery consists of 3813 1000 m x 1000 m lidar tiles in five blocks:

Block 01 delivery consists of 322 1000 m x 1000 m lidar tiles.

Block 02 delivery consists of 871 1000 m x 1000 m lidar tiles.

Block 03 delivery consists of 789 1000 m x 1000 m lidar tiles.

Block 04 delivery consists of 557 1000 m x 1000 m lidar tiles.

Block 05 delivery consists of 1274 1000 m x 1000 m lidar tiles.

Purpose:

The eastern coastline of Texas has been identified as having critical topographic and bathymetric data gaps by NOAA. This lidar data will fill those critical gaps.

Supplemental Information:

The full workflow used for this project is found in the final project report submitted to NOAA.

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 > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY > COASTAL BATHYMETRY
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
ISO 19115 Topic Category
elevation
UNCONTROLLED
None beach
None erosion

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
VERTICAL LOCATION > LAND SURFACE
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > SEA FLOOR

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:

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: National Oceanic and Atmospheric Administration (NOAA), National Geodetic Survey (NGS), Remote Sensing Division (RSD), Coastal Mapping Program (CMP)

Support Roles

Data Steward

CC ID: 998360
Date Effective From: 2020
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: 998358
Date Effective From: 2020
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: 998359
Date Effective From: 2020
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

Originator

CC ID: 998361
Date Effective From: 2020
Date Effective To:
Contact (Organization): National Geodetic Survey (NGS)
Address: 1315 East-West Hwy
Silver Spring, MD 20910
URL: https://geodesy.noaa.gov/

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1145427
W° Bound: -96
E° Bound: -95.33
N° Bound: 28.92
S° Bound: 28.571

Extent Group 1 / Time Frame 1

CC ID: 1145426
Time Frame Type: Range
Start: 2018-10-22
End: 2019-05-31

Extent Group 2

Extent Group 2 / Geographic Area 1

CC ID: 1145430
W° Bound: -94.78
E° Bound: -94.42
N° Bound: 29.57
S° Bound: 29.32

Extent Group 2 / Time Frame 1

CC ID: 1145429
Time Frame Type: Range
Start: 2018-10-22
End: 2019-05-31

Extent Group 3

Extent Group 3 / Geographic Area 1

CC ID: 1145433
W° Bound: -95.39
E° Bound: -94.68
N° Bound: 29.41
S° Bound: 28.89

Extent Group 3 / Time Frame 1

CC ID: 1145432
Time Frame Type: Range
Start: 2018-10-22
End: 2019-05-31

Extent Group 4

Extent Group 4 / Geographic Area 1

CC ID: 1145436
W° Bound: -97.244
E° Bound: -96.89
N° Bound: 28.179
S° Bound: 27.65

Extent Group 4 / Time Frame 1

CC ID: 1145435
Time Frame Type: Range
Start: 2018-10-22
End: 2019-05-31

Extent Group 5

Extent Group 5 / Geographic Area 1

CC ID: 1145439
W° Bound: -96.89
E° Bound: -95.98
N° Bound: 28.68
S° Bound: 27.99

Extent Group 5 / Time Frame 1

CC ID: 1145438
Time Frame Type: Range
Start: 2018-10-22
End: 2019-05-31

Spatial Information

Spatial Representation

Representations Used

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

Reference Systems

Reference System 1

CC ID: 1145424

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 or 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: 998362
Start Date: 2020
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9215
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2020 - 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.

File Type (Deprecated): Zip
Compression: Zip

Distribution 2

CC ID: 998363
Start Date: 2020
End Date: Present
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9215/
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2020 - 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.

File Type (Deprecated): LAZ
Distribution Format: LAS/LAZ - LASer
Compression: Zip

URLs

URL 1

CC ID: 998364
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9215/supplemental/extent_ngs_topobath_postHarvey_tx_m9215.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 2

CC ID: 998365
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: 998366
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9215/supplemental/TX1803_TB_C_Topobathy_Lidar_Project_Report.pdf
Name: Report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Acquisition and Processing Report

Technical Environment

Description:

OS Independent

Data Quality

Accuracy:

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 30.0 cm based on the 95th percentile. All checkpoints located in bathymetric areas were used to compute an accuracy for the bathymetric data. Project specifications required bathymetric data to meet or exceed 35.3 cm at the 95% confidence level based on RMSEz (18.5 cm) x 1.9600.

Horizontal Positional Accuracy:

Only checkpoints photo-identifiable in the intensity imagery can be used to test the horizontal accuracy of the lidar. Photo-identifiable checkpoints in intensity imagery typically include checkpoints located at the ends of paint stripes on concrete or asphalt surfaces or checkpoints located at 90 degree corners of different reflectivity, e.g. a sidewalk corner adjoining a grass surface. The xy coordinates of checkpoints, as defined in the intensity imagery, are compared to surveyed xy coordinates for each photo-identifiable checkpoint. These differences are used to compute the tested horizontal accuracy of the lidar. As not all projects contain photo-identifiable checkpoints, the horizontal accuracy of the lidar cannot always be tested.

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. Horizontal positional accuracy is achieved through rigorous processing of airborne GPS and IMU, use of control, and calibration procedures. This data set was produced 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.

Vertical Positional Accuracy:

This 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= 7.1 cm, equating to +/- 13.8 cm at 95% confidence level.

This lidar dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10 cm RMSEz Vertical Accuracy Class. Actual VVA accuracy was found to be +/- 26.4 cm at the 95th percentile. The 5% outliers consisted of 3 checkpoints with DZ values larger than the 95th percentile. The larger DZ values were recorded at 37.9 cm, 30.0 cm, and 27.7 cm.

This lidar dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 18.5 cm RMSEz Vertical Accuracy Class. Actual Bathymetric accuracy was found to be RMSEz = 14.9 cm, equating to +/- 29.2 cm at 95% confidence level.

Comparability:

The vertical accuracy of the lidar was tested by Dewberry with 134 independent survey checkpoints. The survey checkpoints are located in areas of non-vegetated terrain, including bare earth, open terrain, and urban terrain (72), vegetated terrain, including forest, brush, tall weeds, crops, and high grass (50), and submerged bottom areas (12). The vertical accuracy is tested by comparing survey checkpoints to a triangulated irregular network (TIN) that is created from the lidar ground and submerged bottom 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. The 134 survey checkpoints were not evenly distributed throughout the project area. The lack of municipal development surrounding Matagorda Bay hindered accessibility to this area.

Completeness Report:

Data covers the project boundary.

Conceptual Consistency:

Not applicable

Quality Control Procedures Employed:

Because swath data is tested prior to any classification, only non-vegetated (open terrain, bare earth and urban) checkpoints are used in this testing. All checkpoints located in non-vegetated terrain were used to compute the NVA of the unclassified swath data. Project specifications require a NVA of 19.6 cm at the 95% confidence level based on RMSEz (10 cm) x 1.9600. The unclassified swath lidar dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10 cm RMSEz Vertical Accuracy Class.

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-CO
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?:

Data is backed up to tape and to cloud storage.

Lineage

Sources

Acquisition

CC ID: 1145418
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Leading Edge Geomatics

Data Processing

CC ID: 1145419
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Dewberry

Process Steps

Process Step 1

CC ID: 1145420
Description:

Data for the coastline for the TX1803 topobathy project was acquired by Leading Edge Geomatics using a Leica Chiroptera II Bathymetric and Topographic lidar sensor. All delivered lidar data is referenced to:

Horizontal Datum-NAD83 (2011) epoch: 2010

Projection-UTM Zone 14 North

Projection-UTM Zone 15 North

Horizontal Units-meters

Vertical Datum-NAD83 (2011)

Vertical Units-meters

This dataset encompasses 3813 1000 m x 1000 m tiles. Both green lidar data and NIR lidar data were acquired.

Leading Edge Geomatics acquired, calibrated and performed the refraction correction to the lidar data.

Process Date/Time: 2019-12-01 00:00:00
Process Contact: National Geodetic Survey (NGS)

Process Step 2

CC ID: 1145421
Description:

Dewberry received the calibrated green and NIR data and verified complete coverage. Relative accuracy of the green swaths compared to overlapping and adjacent green swaths as well as the relative accuracy of green swaths compared to overlapping and adjacent NIR swaths were verified through the use of Delta-Z (DZ) orthos created in GeoCue software. Visual inspections using z-range rasters were used to verify intraswath or within a swath relative accuracy. Profiles of elevated planar features, such as roofs, were used to verify horizontal alignment between overlapping swaths. Dewberry then verified absolute vertical accuracy of the swath data prior to full-scale production.

Dewberry used algoritms in TerraScan to create the intial ground/submerged topography surface.

Dewberry used rasterized aggregate extents of refracted points to create automated, smoothed 2-D refraction extent vectors with LAStools and ArcGIS. Light travels at different speeds in air versus water and its speed and direction of travel change when it enters the water column. The refraction correction process accounts for this difference by adjusting the depth (distance traveled) and horizontal position (change of angle/direction) of the lidar points acquired within water. These refraction extents delineate areas where the refraction correction was applied to the lidar data by Leica's automated refraction correction software based on the software's detection of water.

Process Date/Time: 2019-12-01 00:00:00
Process Contact: National Geodetic Survey (NGS)

Process Step 3

CC ID: 1145422
Description:

All lidar data was peer-reviewed. Dewberry's QAQC also included creating void polygons for use during review. All necessary edits were applied to the dataset. GeoCue software was used to update LAS header information, including all projection and coordinate reference system information. The final lidar data are in LAS format 1.4 and point data record format 6.

The final classificaton scheme is as follows:

0-Created, never classified

1-Unclassified

2-Ground

7-Noise

40-Bathymetric bottom

41-Water surface

42-Derived water surface

43-Submerged object, not otherwise specified

44-International Hydrograpic Organization (IHO) S-57 object

45-No bottom found

46-Temporal change

All data was then verified by an independent QC department within Dewberry. The independent QC was performed by analysts who do not perform manual classification or editing. The independent QC involved quantitative and qualitative reviews.

Process Date/Time: 2019-12-01 00:00:00
Process Contact: National Geodetic Survey (NGS)

Process Step 4

CC ID: 1145423
Description:

The NOAA Office for Coastal Management (OCM) received files in laz format. The files contained lidar elevation and intensity measurements. The data were in UTM Zone 14 and UTM Zone 15 coordinates and ellipsoid elevations in meters. OCM performed the following processing on the data for Digital Coast storage and provisioning purposes:

1. Converted from UTM Zone 14 and 15 to geographic coordinates

2. Sorted by gps time.

3. Moved data from class 46 to class 22

The final classification scheme is as follows:

1 - Unclassified

2 - Ground

7 - Noise

22 - Temporal Exclusion

40 - Bathymetric Bottom or Submerged Topography

41 - Water Surface

42-Derived water surface

43 - Submerged feature

45 - Water Column

Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 63297
GUID: gov.noaa.nmfs.inport:63297
Metadata Record Created By: Maryellen Sault
Metadata Record Created: 2020-12-10 18:35+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2023-10-17 16:12+0000
Metadata Record Published: 2022-03-16
Owner Org: NGS
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