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Short Citation:
National Geodetic Survey, 2024: 2021 NOAA NGS Topobathy Lidar DEM Southern Tampa Bay, Florida, https://www.fisheries.noaa.gov/inport/item/66914.

Item Identification

Title: 2021 NOAA NGS Topobathy Lidar DEM Southern Tampa Bay, Florida
Status: Completed
Creation Date: 2022
Abstract:

These data were collected by Dewberry using a CZMIL Nova system. The data were acquired from 20210126 - 20210227. The data include topobathy data in LAS 1.4 format classified as unclassified (1); ground (2); low noise (7); high noise (18); bathymetric bottom (40); water surface (41); derived water surface (42); submerged object, not otherwise specified (e.g., wreck, rock, submerged piling) (43); and no bottom found (bathymetric lidar point for which no detectable bottom return was received) (45) in accordance with project specifications; temporal surface not used in bathymetric classification (65). This dataset consists of approximately 225 square miles of data along the shores of Tampa Bay and contains 52 5000 m x 5000 m DEM tiles.

Purpose:

This lidar data are an ancillary product of NOAA's Coastal Mapping Program (CMP), created through a wider Integrated Ocean and Coastal Mapping initiative to increase support for multiple uses of the data. It is not intended for mapping, charting, or navigation.

Supplemental Information:

Data are generated from lidar returns. Outliers or false returns (e.g., returns from birds, atmospheric particles, and/or system noise) may be present in the data. An automated ground classification algorithm was used to determine bare earth point classification. It should be noted that not all returns were correctly classified; therefore the user should examine for acceptability.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > TOPOGRAPHICAL RELIEF MAPS
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > SEAFLOOR TOPOGRAPHY
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
ISO 19115 Topic Category
elevation

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > FLORIDA

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 National Geodetic Survey, the Office for Coastal Management, or its partners.

Data Set Credit: We request that you credit the National Oceanic and Atmospheric Administration (NOAA) when you use these data in a report, publication, or presentation.

Support Roles

Data Steward

CC ID: 1164750
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 1164751
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 1164752
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Originator

CC ID: 1164753
Date Effective From: 2022
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: 1297450
W° Bound: -82.734502
E° Bound: -82.353336
N° Bound: 27.815211
S° Bound: 27.472667

Extent Group 1 / Time Frame 1

CC ID: 1297449
Time Frame Type: Range
Start: 2021-01-26
End: 2021-02-27

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Reference Systems

Reference System 1

CC ID: 1297447

Coordinate Reference System

CRS Type: Projected
EPSG Code: EPSG:6346
EPSG Name: NAD83(2011) / UTM zone 17N
See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
Data Access Procedure:

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9481;

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: 1164754
Start Date: 2022
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9481
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

File Type (Deprecated): ZIP
Compression: Zip

Distribution 2

CC ID: 1164755
Start Date: 2022
End Date: Present
Download URL: https://noaa-nos-coastal-lidar-pds.s3.us-east-1.amazonaws.com/dem/NGS_South_TampBay_Topobathy_2021_9481/index.html
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Bulk Download
Description:

Simple download of data files.

File Type (Deprecated): GeoTIFF
Distribution Format: GeoTIFF

URLs

URL 1

CC ID: 1164756
URL: https://coast.noaa.gov/dataviewer
Name: Digital Coast Data Access Viewer
URL Type:
Online Resource

URL 2

CC ID: 1164757
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9480/supplemental/FL2101_Quality_Assurance_Report_v02.pdf
Name: QA Topobathy Lidar Data Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

QA Topobathymetric Lidar Data Report

URL 3

CC ID: 1164758
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9480/supplemental/extent_ngs_southTampaBay_topobathy_m9480.kmz
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic shows the lidar footprint for this dataset

URL 4

CC ID: 1167159
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9480/supplemental/Appendix_A_FL2101_TampaBay_TopoBathymetric_Lidar_Ground_Survey_Report.pdf
Name: Topobathy Lidar Ground Survey Report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Topobathy Lidar Ground Survey Report

Technical Environment

Description:

OS Independent

Data Quality

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.

The DEMs are derived from the source lidar and inherit the accuracy of the source data. The DEMs are created using controlled and tested methods to limit the amount of error introduced during DEM production. 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. 11 photo-identifiable checkpoints were used to test horizontal accuracy for this lidar dataset. Horizontal accuracy from this small dataset cannot be considered statistically significant; however, it was still calculated and found to be 26.2 cm.

Vertical Positional Accuracy:

The DEMs are derived from the source lidar and inherit the accuracy of the source data. The DEMs are created using controlled and tested methods to limit the amount of error introduced during DEM production so that any differences identified between the source lidar and final DEMs can be attributed to interpolation differences. DEMs are created by averaging several lidar points within each pixel which may result in slightly different elevation values at a given location when compared to the source LAS, which does not average several lidar points together but may interpolate (linearly) between two or three points to derive an elevation value. The vertical accuracy of the final topobathymetric DEMs was tested by Dewberry with 51 independent checkpoints. The same checkpoints that were used to test the source lidar data were used to validate the vertical accuracy of the final DEM products. 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 (30); vegetated terrain, including forest, brush, tall weeds, crops, and high grass (17); and submerged bottom areas (4). The vertical accuracy is tested by extracting the elevation of the pixel that contains the x/y coordinates of the checkpoint and comparing these DEM elevations to the surveyed elevations. All checkpoints located in non-vegetated terrain were used to compute the Non-vegetated Vertical Accuracy (NVA). Project specifications require 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 require a VVA of 29.4 cm based on the 95th percentile. All checkpoints located in bathymetric areas were used to compute an accuracy for the bathymetric data. Project specifications require the vertical accuracy for bathymetric data to be 58.8 cm or better at the 95% confidence level based on depth-dependent RMSEz (30.0 cm) x 1.9600.

This DEM 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 = 5.7 cm, equating to +/- 11.2 cm at 95% confidence level.

This DEM 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 +/- 15.1 cm at the 95th percentile. The 5% outliers consisted of 1 checkpoint that is larger than the 95th percentile. This checkpoint has a DZ value of 30.2 cm.

This DEM dataset was tested to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 30.0 cm RMSEz Vertical Accuracy Class. Actual Bathymetric accuracy was found to be RMSEz = 15.5 cm, equating to +/- 30.4 cm at 95% confidence level.

Completeness Report:

Data covers 52 5000 m x 5000 m DEM tiles.

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: 1297445
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Dewberry

Process Steps

Process Step 1

CC ID: 1297446
Description:

Data were processed to an initial LAS format using Teledyne CARIS software. CARIS was also utilized for GPS and inertial processing, and Terrasolid and LAStools were used for data visualization, 3D editing, and export to final LAS/LAZ. Data were processed using NAD83(2011) horizontal and vertical datums. The data are in UTM Zone 17 coordinates and ellipsoid elevations in meters. The data classifications are: unclassified (1); ground (2); noise (7); water surface (topographic sensor) (18); bathymetric bottom (40); water surface (41); derived water surface (42); submerged object, not otherwise specified (e.g., wreck, rock, submerged piling) (43); and no bottom found (bathymetric lidar point for which no detectable bottom return was received) (45) in accordance with project specifications; temporal surface not used in bathymetric classification (65).

DEMs created from lidar ground classes (2 and 40) were transformed from ellipsoid heights to orthometric heights, referenced to NAVD88 Geoid 18, meters. All tiled DEMs incorporate the use of the void polygons to enforce areas of NoData (no valid bathymetric returns) greater than 9 sq m in the bathymetry.

Process Date/Time: 2021-10-28 00:00:00
Process Contact: National Geodetic Survey (NGS)

Catalog Details

Catalog Item ID: 66914
GUID: gov.noaa.nmfs.inport:66914
Metadata Record Created By: Maryellen Sault
Metadata Record Created: 2022-03-30 12:24+0000
Metadata Record Last Modified By: Maryellen Sault
Metadata Record Last Modified: 2024-08-15 12:33+0000
Metadata Record Published: 2024-01-10
Owner Org: NGS
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-04-11
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-04-11