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Short Citation:
OCM Partners, 2023: 2018 USGS Lidar DEM: Post Hurricane Maria - Puerto Rico, https://www.fisheries.noaa.gov/inport/item/60105.

Item Identification

Title: 2018 USGS Lidar DEM: Post Hurricane Maria - Puerto Rico
Status: Completed
Publication Date: 2020-03-11
Abstract:

This data set was retrieved from the USGS rockyftp website and processed to NOAA/OCM's Digital Coast.

Product: These are Digital Elevation Model (DEM) data for Puerto Rico and its surround islands as part of the required deliverables for the PR USVI 2018 Lidar project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 0.5 meter hydro-flattened Raster DEM.

Geographic Extent: Puerto Rico, covering approximately 3,585 square miles.

Dataset Description: PR USVI Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3. The data was developed based on a horizontal projection/datum of NAD83 (2011), Puerto Rico and Virgin Islands, meters and vertical datum of PRVD02 (GEOID12B), meters. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 4,374 individual 1500 m x 1500 m tiles, as tiled Intensity Imagery, and as tiled bare earth DEMs; all tiled to the same 1500 m x 1500 m schema.

Ground Conditions: Lidar was collected in late 2018, while no snow was on the ground and rivers were at or below normal levels. Cloud cover prevented the acquisition of portions of the island, mainly in the east. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Leading Edge Geomatics established a total of 112 ground control points that were used to calibrate the lidar to known ground locations established throughout the Puerto Rico project area. An additional 167 independent accuracy checkpoints, 96 in Bare Earth and Urban landcovers (96 NVA points), 71 in Tall Grass and Brushland/Low Trees categories (71 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

Purpose:

To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 0.5 meter cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.

Supplemental Information:

USGS Contract No. G16PC00020 CONTRACTOR: Dewberry SUBCONTRACTOR: Leading Edge Geomatics Lidar data were acquired and calibrated by Leading Edge Geomatics. All follow-on processing was completed by the prime contractor.

Raster File Type = IMG (originals)

Bit Depth/Pixel Type = 32-bit float

Raster Cell Size = 0.5 meters

Interpolation or Resampling Technique = Triangulated Irregular Network

Required Vertical Accuracy = 19.6 cm NVA

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 > COASTAL PROCESSES > COASTAL ELEVATION
ISO 19115 Topic Category
elevation

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > CARIBBEAN SEA > PUERTO RICO
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > LAND SURFACE
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > SEA FLOOR
UNCONTROLLED
Global Change Master Directory (GCMD) Location Keywords U.S. Coastline

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: USGS, Dewberry

Support Roles

Data Steward

CC ID: 912650
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: 912649
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: 912651
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

Point of Contact

CC ID: 912652
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

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1154409
W° Bound: -67.955381
E° Bound: -65.218638
N° Bound: 18.517999
S° Bound: 17.874351

Extent Group 1 / Time Frame 1

CC ID: 1154408
Time Frame Type: Range
Start: 2018-04-17
End: 2019-04-18

Spatial Information

Spatial Representation

Representations Used

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

Vector Representation 1

CC ID: 912665
Point Object Present?: No

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: 912653
Start Date: 2020-06-19
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9101/details/9101
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.

File Type: Zip
Compression: Zip

Distribution 2

CC ID: 912654
Start Date: 2020-06-19
End Date: Present
Download URL: https://coast.noaa.gov/htdata/raster2/elevation/USGS_PostMaria_PuertoRico_DEM_2018_9101/
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2020 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in native projection and geotiff format.

File Type: GeoTIFF

URLs

URL 1

CC ID: 912655
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: 912656
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9102/supplemental/extent_PR_2018_m9102.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 3

CC ID: 912657
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9102/supplemental/Appendix_A_Survey_Report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 4

CC ID: 912658
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9102/supplemental/Appendix_B_Ground_Control_Survey_Report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 5

CC ID: 912659
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9102/supplemental/Appendix_D_GPS_Processing.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 6

CC ID: 912660
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/9102/supplemental/PR_USVI_Lidar_2018_Project_Report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

Technical Environment

Description:

Riegl software for initial point cloud processing; GeoCue; Microstation/Terrascan; ArcGIS 10.5; Windows 7 Operating System

Data Quality

Horizontal Positional Accuracy:

The island of Puerto Rico and its surrounding islands were 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. Seventeen (17) checkpoints were photo-identifiable but do not produce a

statistically significant tested horizontal accuracy value. Using this small sample set of photo identifiable checkpoints, positional accuracy of this dataset was found to be RMSEx = 15.5 cm

and RMSEy = 12.2 cm which equates to +/- 34.1 cm at 95% confidence level. While not statistically significant, the results of the small sample set of checkpoints are within the produced to meet horizontal accuracy

Vertical Positional Accuracy:

The same 232 checkpoints that were used to test the vertical accuracy of the lidar were used to validate the vertical accuracy of the final DEM products as well. Accuracy results may vary between the source lidar and final DEM deliverable. DEMs are created by averaging several lidar points within each pixel which may result in slightly different elevation values at each survey checkpoint 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 DEM 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. Dewberry typically uses LP360 software to test the swath lidar vertical accuracy, Terrascan software to test the classified lidar vertical accuracy, and Esri ArcMap to test the DEM vertical accuracy so that three different software programs are used to validate the vertical accuracy for each project.

the tested vertical accuracy results from a comparison of the surveyed checkpoints to the elevation values present within the final island of Puerto Rico and its surrounding islands DEM dataset.

NVA ― Non-vegetated Vertical Accuracy (RMSEz x 1.9600) Spec = 19.6 cm. Tested = 13.4 cm

NVA RMSe = 6.83 cm

Completeness Report:

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Conceptual Consistency:

Data covers the entire area specified for this project. Because parts of the PR USVI 2018 Lidar project were collected in areas where there are clouds virtually every day of the year, there are some ground voids. With the current available technology, lidar sensors cannot penetrate clouds. The noise from clouds was removed from the classified lidar dataset, however, this resulted in some areas having ground voids.

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

Processed Lidar

CC ID: 1154402
Contact Role Type: Originator
Contact Type: Organization
Contact Name: Dewberry

Process Steps

Process Step 1

CC ID: 1154403
Description:

The boresight for each lift was done individually as the solution may change slightly from lift to lift. The following steps describe the Raw Data Processing and Boresight process: 1) Technicians processed the raw data to LAS format flight lines using the final GPS/IMU solution. This LAS data set was used as source data for boresight. 2) Technicians first used Riegl software to calculate initial boresight adjustment angles based on sample areas selected in the lift. These areas cover calibration flight lines collected in the lift, cross tie and production flight lines. These areas are well distributed in the lift coverage and cover multiple terrain types that are necessary for boresight angle calculation. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable for the selected areas. 3) Once the boresight angle calculation was completed for the selected areas, the adjusted settings were applied to all of the flight lines of the lift and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight line overlaps match for the entire lift and adjusted as necessary until the results met the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was less than or equal to 6 cm RMSEz within individual swaths and less than or equal to 8 cm RMSEz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the boresighted flight lines against the surveyed check points after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met. Point classification was performed according to USGS Lidar Base Specification 1.3, and breaklines were collected for water features. Bare earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening.

Process Date/Time: 2018-10-04 00:00:00

Process Step 2

CC ID: 1154404
Description:

LAS Point Classification: The point classification is performed as described below. The bare earth surface is then manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface is finalized, it is then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) lidar data inside of the Lake Pond, Tidal, and Double Line Drain hydro flattening breaklines were then classified to water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 0.35 meters was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 20). All Lake Pond Island, Tidal, and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to approved classes by USGS. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. Due to software limitations within TerraScan, these classes were used to trip the withheld bit within various software packages. These processes were reviewed and accepted by USGS through numerous conference calls and pilot study areas. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper us used as a final check of the bare earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for both the All Point Cloud Data and the Bare Earth. Proprietary software was used to perform final statistical analysis of the classes in the LAS files, on a per tile level to verify final classification metrics and full LAS header information.

Process Date/Time: 2019-10-04 00:00:00

Process Step 3

CC ID: 1154405
Description:

The NOAA Office for Coastal Management (OCM) downloaded this data set from these USGS sites:

ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/OPR/Projects/ PR_PRVI_A_2018// /PR_PRVI_C_2018 /PR_PRVI_D_2018 /PR_PRVI_E_2018 /PR_PRVI_F_2018 /PR_PRVI_G_2018

The total number of TIFF files downloaded and processed was 4,699.

The data were in Puerto Rico/USVI State Plane (3500) (NAD83 2011), meters coordinates and PRVD02 (Geoid12B) elevations in meters. The bare earth raster files were at a 0.5 meter grid spacing.

OCM performed the following processing on the data for Digital Coast storage and provisioning purposes:

1. Used an internal script to assign the EPSG codes (Horiz - 6566, Vert - 6641) and convert to cloud-optimized GeoTiff format.

2. Copied to the files to https

Process Contact: Office for Coastal Management (OCM)

Process Step 4

CC ID: 1154406
Description:

Hydro Flattened Raster DEM Process: Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 0.5 meter hydro-flattened Raster DEM. Using automated scripting routines within ArcMap, an ERDAS Imagine IMG file was created for each tile. Each surface is reviewed using Global Mapper to check for any surface anomalies or incorrect elevations found within the surface.

Catalog Details

Catalog Item ID: 60105
GUID: gov.noaa.nmfs.inport:60105
Metadata Record Created By: Blake Waring
Metadata Record Created: 2020-06-22 09:04+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: OCMP
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