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Summary

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Short Citation
National Geodetic Survey, 2024: 2018-2019 NOAA NGS Topobathy Lidar: Trappe to Toddville, MD, https://www.fisheries.noaa.gov/inport/item/64564.
Full Citation Examples

Abstract

The NOAA Chesapeake Bay MD1804 Option 1 East 4 Topobathymetric lidar data were collected by NV5 Geospatial (NV5) using Riegl VQ-880-G, VQ-880-GII, and VQ-880-GH systems. The Chesapeake Bay MD1804 Option 1 East 4 acquisition spanned from 20181107-20190417 in 14 missions. The Chesapeake Bay MD1804 Option 1 East 4 dataset includes Topobathymetric data in LAS format 1.4, point data record format 6, with the following classifications in accordance with project specifications and the American Society for Photogrammetry and Remote Sensing (ASPRS) classification standards:

1 - unclassified

2 - ground

7 - noise

40 - bathymetric bottom or submerged topography

43 - submerged feature

45 - water column

46 - overlap bathymetric bottom

71 - adjacent lift unclassified

72 - adjacent lift ground

85 - adjacent lift water column

1 Overlap - edge clip

This data set also includes lidar intensity values, number of returns, return number, time, and scan angle. The 100 meter buffered NOAA Chesapeake Bay MD1804 Option 1 East 4 project area covers approximately 563.829 square kilometers of an area encompassing a portion of the Chesapeake Bay and the nearby census designated places of Taylors Island, Cambridge, Madison, Woolford, and Algonquin, Maryland. LAS files were compiled in 500 m x 500 m tiles. The NOAA Chesapeake Bay MD1804 Option 1 East 4 dataset is comprised of 2,909 - 500 m x 500 m LAS tiles.

Distribution Information

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

  • LAS/LAZ - LASer

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

Access Constraints:

None

Use Constraints:

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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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

Contact Information

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

Extents

Geographic Area 1

-76.402284° W, -76.023552° E, 38.668565° N, 38.295295° S

Time Frame 1
2018-11-07 - 2019-04-17

Item Identification

Title: 2018-2019 NOAA NGS Topobathy Lidar: Trappe to Toddville, MD
Status: Completed
Publication Date: 2021
Abstract:

The NOAA Chesapeake Bay MD1804 Option 1 East 4 Topobathymetric lidar data were collected by NV5 Geospatial (NV5) using Riegl VQ-880-G, VQ-880-GII, and VQ-880-GH systems. The Chesapeake Bay MD1804 Option 1 East 4 acquisition spanned from 20181107-20190417 in 14 missions. The Chesapeake Bay MD1804 Option 1 East 4 dataset includes Topobathymetric data in LAS format 1.4, point data record format 6, with the following classifications in accordance with project specifications and the American Society for Photogrammetry and Remote Sensing (ASPRS) classification standards:

1 - unclassified

2 - ground

7 - noise

40 - bathymetric bottom or submerged topography

43 - submerged feature

45 - water column

46 - overlap bathymetric bottom

71 - adjacent lift unclassified

72 - adjacent lift ground

85 - adjacent lift water column

1 Overlap - edge clip

This data set also includes lidar intensity values, number of returns, return number, time, and scan angle. The 100 meter buffered NOAA Chesapeake Bay MD1804 Option 1 East 4 project area covers approximately 563.829 square kilometers of an area encompassing a portion of the Chesapeake Bay and the nearby census designated places of Taylors Island, Cambridge, Madison, Woolford, and Algonquin, Maryland. LAS files were compiled in 500 m x 500 m tiles. The NOAA Chesapeake Bay MD1804 Option 1 East 4 dataset is comprised of 2,909 - 500 m x 500 m LAS tiles.

Purpose:

This lidar data was required by National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS), Remote Sensing Division Coastal Mapping Program (CMP) to enable accurate and consistent measurement of the national shoreline. The CMP works to provide a regularly updated and consistent national shoreline to define America's marine territorial limits and manage coastal resources.

Supplemental Information:

The NOAA Chesapeake Bay MD1804 Option 1 East 4 data includes all lidar returns. An automated grounding classification algorithm was used to determine bare earth and submerged topography point classification. The automated grounding was followed with manual editing. Depth values were adjusted per sensor to NOAA provided ground truth data. Classes 2 (ground), 40 (submerged topography), and 43 (submerged feature) were used to create the final DEMs. The full workflow used for this project will be documented in the NOAA Chesapeake Bay MD1804 Option 1 East 4 Topobathymetric lidar final report, to be provided upon project completion.

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: 1063570
Date Effective From: 2021
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: 1063568
Date Effective From: 2021
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: 1063569
Date Effective From: 2021
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: 1063571
Date Effective From: 2021
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: 1145897
W° Bound: -76.402284
E° Bound: -76.023552
N° Bound: 38.668565
S° Bound: 38.295295

Extent Group 1 / Time Frame 1

CC ID: 1145896
Time Frame Type: Range
Start: 2018-11-07
End: 2019-04-17

Spatial Information

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: 1145894

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: 1063572
Start Date: 2021-05
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9298
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2021 - 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: 1063573
Start Date: 2020-05
End Date: Present
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9298/index.html
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2021 - 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: 1063574
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9298/supplemental/extent_ngs_topobath_trappeMD_m9298.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: 1063575
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: 1065708
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9298/supplemental/NOAA_Chesapeake_Bay_Option_1_Lidar_and_Shoreline_Mapping_Report_v02.pdf
Name: Lidar Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Link to lidar report

Technical Environment

Description:

OS Independent

Data Quality

Horizontal Positional Accuracy:

Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95 percent of the time (ACCr). Based on a flying altitude of 400 meters, an IMU error of 0.005 decimal degrees, and a GNSS positional error of 0.125 meters, the RMSEr value for The NOAA Chesapeake Bay MD1804 Option 1 East 4 project area is 0.139 meters, with a ACCr of 0.24 meters at the 95% confidence level. The project specification requires horizontal positions to be accurate to 1.0m(RMSE).

Vertical Positional Accuracy:

Absolute accuracy was assessed using Non-Vegetated Vertical Accuracy (NVA) survey methods. Survey check points were evenly distributed as feasible throughout the project area. NVA compares known ground check point data that were withheld from the calibration and post-processing of the lidar point cloud to the triangulated surface generated by the ground-classified lidar point cloud. NVA is a measure of the accuracy of lidar point data in open areas with level slope (less than 20 degrees) where the lidar system has a high probability of measuring the ground surface and is evaluated at the 95% confidence interval (1.96*RMSE). In The NOAA Chesapeake Bay MD1804 Option 1 East 4 data extent, 15 survey checkpoints were used to assess the non-vegetated vertical accuracy. Project specifications require NVA meet 0.196 m accuracy at the 95% confidence interval. Submerged topography points were tested separately. In the NOAA Chesapeake Bay MD1804 Option 1 East 4 data extent, 107 survey checkpoints were used to assess the submerged topography accuracy. Project specifications require submerged topography shall meet a vertical RMSE of QL2b specified in the Draft National Coastal Mapping strategy 1.0 which is equivalent to 0.30 m RMSE at a depth of 1 m. Please refer to the NOAA Chesapeake Bay MD1804 Option 1 East 4 Topobathymetric lidar final data report for final accuracies, to be provided upon project completion.

The NOAA Chesapeake Bay MD1804 Option 1 East 4 dataset Non-Vegetated Vertical Accuracy tested 0.065 m vertical accuracy at the 95% confidence level against the ground-classified lidar point cloud in open terrain using 15 ground check points, based on RMSEz (0.033 m) x 1.9600.

The NOAA Chesapeake Bay MD1804 Option 1 East 4 dataset submerged topography accuracy tested 0.061 m vertical accuracy at the 95% confidence level against the classified points cloud using 107 submerged check points, based on RMSEz (0.031 m) x 1.9600. Submerged topography checkpoints usually occur in depths up to 1m.

Completeness Report:

Data covers the project boundary.

Conceptual Consistency:

Not applicable

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 and Processing

CC ID: 1145890
Contact Role Type: Originator
Contact Type: Organization
Contact Name: NV5 Geospatial, Inc

Process Steps

Process Step 1

CC ID: 1145891
Description:

Data for the NOAA Chesapeake Bay MD1804 Option 1 East 4 Topobathymetric lidar project area was acquired by NV5 Geospatial (NV5) using Riegl VQ-880-G, VQ-880-GII, and VQ-880-GH Topobathymetric lidar systems. All derived LAS data is referenced to:

Horizontal Datum-NAD83(2011) epoch: 2010.00

Projection-UTM Zone 18N

Horizontal Units-meters

Vertical Datum-GRS80 Ellipsoid

Vertical Units-meters

The NOAA Chesapeake Bay MD1804 Option 1 East 4 dataset encompasses 2,909 - 500m x 500m tiles in an area encompassing a portion of the Chesapeake Bay and the nearby census designated places of Taylors Island, Cambridge, Madison, Woolford, and Algonquin, Maryland. Lidar data were acquired with VQ-880-G, VQ-880-GII, and VQ-880-GH Riegl sensors.

The collected lidar data were immediately processed in the field by NV5 to a level that will allow QA\QC measures to determine if the sensor is functioning properly and assess the coverage of submerged topography. An initial SBET was created in POSPAC MMS 8.3 SP3 and loaded into RiProcess which applies pre-calibrated angular misalignment corrections of scanner position to extract the raw point cloud into geo-referenced LAS files. These files were inspected for sensor malfunctions and then passed through automated raster generation using LAStools to develop an initial assessment of bathymetric coverage. NV5 reviewed all acquired flight lines to ensure complete coverage and positional accuracy of the laser points. These rasters were also used to create an initial product in Quick Look Coverage Maps. These Quick Look files are not fully processed data or final products but provide rapid assessment of approximate coverage and depth penetration.

NV5 resolved kinematic corrections for aircraft position data using aircraft GNSS and Applanix's proprietary PP-RTX solution. When PP-RTX was not used NV5 conducted static Global Navigation Satellite System (GNSS) ground surveys (1 Hz recording frequency) using base stations over known monument locations during flights. After the airborne survey, static GPS data were triangulated with nearby Continuously Operating Reference Stations (CORS) using the Online Positioning User Service (OPUS) for precise positioning. Multiple independent sessions over the same base station were performed to confirm antenna height measurements and to refine position accuracy. This data was used to correct the continuous on board measurements of the aircraft position recorded throughout the flight. A final smoothed best estimate trajectory (SBET) was developed that blends post-processed aircraft position with attitude data. Using the SBETs, sensor head position and attitude were then calculated throughout the survey. Trimble Business Center v.3.90, Blue Marble Geographic Calculator 2019, and PosPac MMS 8.3 SP3 were used for these processes.

Following final SBET creation, NV5 used RiProcess 1.8.5 to calculate laser point positioning by associating SBET positions to each laser point return time, scan angle, and intensity. Terra 19 and LasTools were used to classify water surface and create a water surface model. They are created for single swaths to ensure temporal differences and wave or water surface height variations between flight lines do not impact the refraction of the bathymetric data. These models are used in NV5's LasMonkey refraction tool to determine the accurate positioning of bathymetric points. All lidar data below water surface models were classified as water column to be refracted. Light travels at different speeds in air versus water and its direction of travel or angle is changed or refracted when entering the water column. The refraction tool corrects for this difference by adjusting the depth (distance traveled) and horizontal positioning (change of angle/direction) of the lidar data. Using raster-based QC methods, the output data is verified to ensure the refraction tool functioned properly.

Process Date/Time: 2020-12-17 00:00:00
Process Contact: NGS Communications and Outreach Branch
Phone (Voice): (301) 713-3242
Email Address: ngs.infocenter@noaa.gov

Process Step 2

CC ID: 1145892
Description:

Once all data was refracted by flight line data was exported to LAS 1.4 format and combined into 500 m x 500 m tiles. Data were then further calibrated using TerraMatch. NV5 used custom algorithms in TerraScan to classify the initial ground/submerged topography surface points. Relative accuracy of overlapping swaths was compared and verified through the use Delta-Z (DZ) orthos created using NV5's Las Product Creator. Absolute vertical accuracy of the calibrated data was assessed using ground survey data and complete coverage was again verified.

Post automated classification NV5 then performed manual editing to review all classification and improve the final Topobathymetric surface. NV5's LasMonkey 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.

1 - unclassified

2 - ground

7 - noise

40 - bathymetric bottom or submerged topography

43 - submerged feature

45 - water column

46 - overlap bathymetric bottom

71 - adjacent lift unclassified

72 - adjacent lift ground

85 - adjacent lift water column

1 Overlap - edge clip

Process Date/Time: 2020-12-17 00:00:00

Process Step 3

CC ID: 1145893
Description:

The NOAA Office for Coastal Management (OCM) received files in las format. The files contained lidar elevation and intensity measurements. The data were in UTM Zone 18 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 17 to geographic coordinates

2. Sorted by gps time

3. Moved classes 46, 71 ,72 and 85 to class 1

4. Compressed the data using laszip.

Process Contact: Office for Coastal Management (OCM)

Child Items

Rubric scores updated every 15m

Rubric Score Type Title
Entity NOAA NGS Topobathy Lidar Class Scheme: Trappe, MD

Catalog Details

Catalog Item ID: 64564
GUID: gov.noaa.nmfs.inport:64564
Metadata Record Created By: Maryellen Sault
Metadata Record Created: 2021-04-26 13:23+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