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National Geodetic Survey, 2022: 2018-2019 NOAA NGS Topobathy Lidar DEM Hurricane Irma: Miami to Marquesas Keys, FL, https://www.fisheries.noaa.gov/inport/item/63018.

Item Identification

Title: 2018-2019 NOAA NGS Topobathy Lidar DEM Hurricane Irma: Miami to Marquesas Keys, FL
Status: Completed
Publication Date: 2020-10-02
Abstract:

The NOAA Hurricane Irma Project area data were collected by Quantum Spatial, Inc. (QSI) using three Riegl systems: a Riegl VQ-880-G+, a Riegl VQ-880-GII, and a Riegl VQ-880-GH. The project acquisition dates spanned from 20181120-20190323 in 85 missions. The final classified LiDAR data were transformed from WGS80 ellipsoid elevations to Geoid12b orthometric elevations and were then used to create topobathymetric bare earth digital elevation models (DEMs) in ERDAS Imagine (*.img) format with a 1m pixel resolution. Ground (2), bathymetric bottom (40), and submerged objects (43) classified points were used in the bare earth DEM creation. The NOAA Hurricane Irma Project digital elevation model (DEM) dataset consists of a bathymetric void clipped bare earth model and an interpolated bare earth model. The 100 meter buffered project area consists of approximately 1,381,270 acres and stretches from the eastern coast of Miami south and westward to the Marquesas Keys. DEM files were compiled in 5,000 m x 5,000 m tiles and clipped to the project boundary. The full project dataset is comprised of 300 - 5,000 m x 5,000 m DEM 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 Hurricane Irma Project 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. Submerged topography elevations were adjusted to correct for sensor depth bias on a per sensor basis using NOAA provided ground truth data. Intensity values of bathymetric bottom returns were normalized for water depth. Total propagated uncertainty (TPU) values were calculated for the bathymetry data. Classes 2 (ground), 40 (submerged topography), and 43 (submerged object) were used to create the final DEMs. The full workflow used for this project will be documented in the NOAA Hurricane Irma Florida Keys 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 DEM
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
UNCONTROLLED
Global Change Master Directory (GCMD) Instrument Keywords Earth Remote Sensing Instruments > Active Remote Sensing > Profilers/Sounders > Lidar/Laser Sounders > LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords
AIRCRAFT

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: 990032
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: 990030
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: 990031
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: 990033
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: 1154392
W° Bound: -82.23
E° Bound: -80.0828
N° Bound: 25.8025
S° Bound: 24.435

Extent Group 1 / Time Frame 1

CC ID: 1154391
Time Frame Type: Range
Start: 2018-11-20
End: 2019-03-23

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: 1154389

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:

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: 990034
Start Date: 2020
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9060
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: Zip
Compression: Zip

Distribution 2

CC ID: 990035
Start Date: 2020
End Date: Present
Download URL: https://coast.noaa.gov/htdata/raster2/elevation/NGS_FL_Topobathy_PostIrma_MiamiToMarquesas_2019_9060
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2020 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in geotiff 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: GeoTIFF

URLs

URL 1

CC ID: 990036
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9081/supplemental/extent_2019_NGS_topobathy_Irma_D1_m9081.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: 990037
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: 990052
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9081/supplemental/NOAA_Supplemental_Irma_Topobathymetric_LiDAR_and_Shoreline_Mapping_Report.pdf
Name: Report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Acquisition and processing 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. Based on a flying altitude of 400 meters, an IMU error of 0.005 decimal degrees, and a GNSS positional error of 0.023 meters, the RMSEr value for the NOAA Hurricane Irma Florida Keys Topobathymetric LiDAR dataset is 0.067 m, with a ACCr of 0.115 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 both Non-Vegetated Vertical Accuracy (NVA) and Vegetated Vertical Accuracy (VVA) survey methods. Survey checkpoints 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 derived gridded bare earth DEM. 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 Hurricane Irma Project area, 36 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. Ground check points located in land cover categories other than bare earth, urban, or submerged topography were used to compute the Vegetated Vertical Accuracy (VVA)against the derived gridded bare earth DEM. In NOAA Hurricane Irma Project area, 22 survey checkpoints were used to assess the vegetated vertical accuracy. Project specifications require VVA meet 0.360 m accuracy based on the 95th percentile. Submerged topography points were also tested. In the NOAA Hurricane Irma Florida Keys Topobathymetric LiDAR Project area, 509 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 0.300 m RMSE at a depth of 1 m.

The NOAA Hurricane Irma Project dataset Non-Vegetated Vertical Accuracy tested 0.083 m vertical accuracy at 95% confidence level against the derived bare earth DEM in open terrain using 36 ground check points, based on RMSEz (0.043 m) x 1.9600.

The NOAA Hurricane Irma Project dataset Vegetated Vertical Accuracy tested 0.129 m vertical accuracy at the 95th percentile against the derived bare earth DEM using 22 landclass points.

The NOAA Hurricane Irma Project dataset tested 0.151 m vertical accuracy at 95% confidence level against the derived topobathymetric bare earth DEM using 509 submerged check points, based on RMSEz (0.077 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: 1154383
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Quantum Spatial (QSI)

Process Steps

Process Step 1

CC ID: 1154384
Description:

Data for the NOAA Hurricane Irma project area was acquired by Quantum Spatial (QSI) using Riegl VQ-880-GII, Riegl VQ-880-GH, and Riegl VQ-880-G+ Topobathy LiDAR systems. All derived DEM data is referenced to:

Horizontal Datum-NAD83(2011) epoch: 2010.00

Projection-UTM Zone 17N

Horizontal Units-meters

Vertical Datum-NAVD88 (Geoid12b)

Vertical Units-meters

The collected LiDAR data were immediately processed in the field by QSI 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. QSI 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 - 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.

QSI resolved kinematic corrections for aircraft position data using aircraft GNSS and Applanix' proprietary PP-RTX solution. When PP-RTX was not used QSI 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 onboard 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.PosPac MMS 8.3 SP3 was used for these processes.

Process Date/Time: 2020-09-15 00:00:00
Process Contact: National Geodetic Survey (NGS)

Process Step 2

CC ID: 1154385
Description:

Following final SBET creation, QSI 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 QSI'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.

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. QSI 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 QSI's Las Product Creator. Absolute vertical accuracy of the calibrated data was assessed using ground survey data and complete coverage was again verified.

Process Date/Time: 2020-09-15 00:00:00
Process Contact: National Geodetic Survey (NGS)

Process Step 3

CC ID: 1154386
Description:

Post automated classification QSI then performed manual editing to review all classification and improve the final topobathymetric surface. QSI'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.

The final classification scheme is as follows:

1 - Unclassified

2 - Ground

7 - Noise

40 - Bathymetric Bottom or Submerged Topography

41 - Water Surface

43 - Submerged feature

45 - Water Column

46 - Temporal Bathymetric Bottom

71 - Overlap Default

72 - Overlap Ground

81 - Overlap Water Surface

85 - Overlap Water Column

1-Overlap - Edge Clip

Process Date/Time: 2020-09-15 00:00:00
Process Contact: National Geodetic Survey (NGS)

Process Step 4

CC ID: 1154387
Description:

QSI transformed the final LiDAR data from ellipsoid heights to orthometric heights referenced to NAVD88, Geoid12B to create the final topobathymetric DEMs. The topobathymetric bare earth DEMs were output at 1 meter resolution in IMG format into 300 5,000 m x 5,000 m tiles. The NOAA Hurricane Irma Project rasters are clipped to the extent of the project boundary and named according to project specifications.

A bathymetric void shapefile was created to indicate areas where there was a lack of bathymetric returns. This shape was created by triangulating bathymetric bottom points with an edge length maximum of 4.56m to identify all areas greater then 9 square meters without bathymetric returns. This shapefile was used to clip and exclude interpolated elevation data from these areas in the bathymetric void clipped topobathymetric bare earth model.

Process Date/Time: 2020-09-15 00:00:00

Process Step 5

CC ID: 1154388
Description:

The NOAA Office for Coastal Management (OCM) received img format files from Quantum Spatial. Horizontal positions were provided in UTM Zone 17 NAD83(2011), meters coordinates. Vertical positions were provided in NAVD88 (Geoid12b) elevations and in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes:

1. The data were converted to GeoTiff format and the projection and vertical datum EPSG codes were assigned..

2. The data were copied to https

Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 63018
GUID: gov.noaa.nmfs.inport:63018
Metadata Record Created By: Maryellen Sault
Metadata Record Created: 2020-10-02 10:32+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+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