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Short Citation:
OCM Partners, 2022: 2007 US Army Corps of Engineers (USACE), Jacksonville District US Virgin Islands LiDAR, https://www.fisheries.noaa.gov/inport/item/50067.

Item Identification

Title: 2007 US Army Corps of Engineers (USACE), Jacksonville District US Virgin Islands LiDAR
Short Name: usace2007_usvi_m559_metadata
Status: Completed
Publication Date: 2008
Abstract:

This Light Detection and Ranging (LiDAR) bare-earth classified LAS dataset is a topographic survey conducted for the

USACE USVI LiDAR Project. These data were produced for The Corps of Engineers Jacksonville District. The USVI LiDAR Survey

consists of the islands of St. Croix, St. Thomas, and St. John. The LiDAR point cloud was flown at a density sufficient to support

the Federal Emergency Management Agency (FEMA) guidelines and specifications. The Atlantic Group acquired the USVI LiDAR Survey

between November 16, 2007 and November 29, 2007. The USVI LiDAR survey was collected under the guidance of a Professional

Mapper/Surveyor.

Original contact information:

Contact Org: 3001 Inc

Title: LiDAR Department

Phone: (985) 661 - 3001

Email: lidar@3001inc.com

Purpose:

The USVI LiDAR Project Survey data will support the creation of Federal Emergency Management Agency Flood Insurance Rate Maps

(FEMA FIRM) and an integrated ground and surface water model.

Notes:

10711

Supplemental Information:

A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/559/supplemental/2007_USACE_Virgin_Islands_Lidar.kmz

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation
UNCONTROLLED
None Contour
None ESRI
None Height
None Hydrography
None Photogrammetry
None Planimetric
None Shapefile
None Stereo Photogrammetry
None TIN

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: None Planned
Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of Corps of Engineers,

Jacksonville District, the Office for Coastal Management, or its partners.

Data Set Credit: Acknowledgement of the Corp of Engineers, Jacksonville District would be appreciated in products derived from these data.

Support Roles

Data Steward

CC ID: 689027
Date Effective From: 2008
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: 689029
Date Effective From: 2008
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: 689030
Date Effective From: 2008
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: 689028
Date Effective From: 2008
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: Publication Date

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1138991
W° Bound: -65.091685
E° Bound: -64.549985
N° Bound: 18.431784
S° Bound: 17.673984

Extent Group 1 / Time Frame 1

CC ID: 1138990
Time Frame Type: Range
Start: 2007-11-16
End: 2007-11-29

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
Data Access Procedure:

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer;

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: 742873
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=559
Distributor:
File Name: Customized Download
Description:

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

Distribution 2

CC ID: 742874
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/559/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 742876
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 742877
URL: https://coast.noaa.gov
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 689056
Activity Date/Time: 2017-01-05
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 689055
Activity Date/Time: 2017-11-14
Description:

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 718671
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 742875
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Technical Environment

Description:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.4.1420

Data Quality

Accuracy:

The USVI LiDAR Project Survey data will support the creation of Federal Emergency Management Agency Flood Insurance Rate Maps (FEMA FIRM)

and an integrated ground and surface water model.

Horizontal Positional Accuracy:

All ground control processing and adjustment is performed using published coordinate horizontal and vertical datums (e.g. NGS CORS).

For deliverables, Corpscon for Windows Version 5.11.08 (geoid 03) was used for horizontal and vertical datum conversion as well as for

coordinate system conversion purposes (e.g. UTM to State Plane).

Vertical Positional Accuracy:

The accuracy assessment was performed using a standard method to compute the root mean square error (RMSE) based on a comparison of

ground control points (GCP) and filtered LiDAR data points. Filtered LiDAR data has had vegetation and cultural features removed and

by analysis represents bare-earth elevations. The RMSE figure was used to compute the vertical National Standard for Spatial Data

Accuracy (NSSDA). Ground control was established by 3001, Inc. A spatial proximity analysis was used to select edited LiDAR data

points contiguous to the relevant GCPs. A search radius decision rule is applied with consideration of terrain complexity, cumulative

error, and adequate sample size. Cumulative error results from the errors inherent in the various sources of horizontal measurement.

These sources include the airborne GPS, GCPs, and the uncertainty of the accuracy of the LiDAR data points. This accuracy is achieved

prior to the sub-sampling that occurs through integration with the inertial measurement unit (IMU) positions that are recorded.

It is unclear at this time whether the initial accuracy is maintained. The horizontal accuracy of the GCPs is estimated to be in the

range of approximately 1 to 1.6 inches. Finally, sample size was considered. The specification for the National Standard for Spatial

Data Accuracy is a minimum of 20 points to conduct a statistically significant accuracy evaluation (Minnesota Planning, 1999,

Positional Accuracy Handbook, Minnesota Planning Land Management Information Center, St. Paul, Minnesota, p.3). Most statistical texts

indicate that a minimum of 30 sample points provide a reasonable approximation of a normal distribution. The intent of the NSSDA is

to reflect the geographic area of interest and the distribution of error in the data set (Federal Geographic Data Committee, 1998,

Geospatial National Standard for Spatial Data Accuracy, Federal Geographic Data Committee Secretariat, Reston, Virginia, p.3-4).

Additional steps were taken to ensure the vertical accuracy of the LiDAR data including:

Step 1: Precision Bore sighting (Check Edge-matching)

Step 2: Compare the LiDAR data to the Field Survey (Field survey is to FEMA specifications and more stringent internal specifications)

Step 3: Automated Filtering

Step 4: Manual Editing (Quality Control) Step 5: 3-D Digitizing and Photogrammetric Compilation of hydrographic breaklines

Completeness Report:

The USVI LiDAR Project Survey data will support the creation of Federal Emergency Management Agency Flood Insurance Rate Maps (FEMA FIRM)

and an integrated ground and surface water model. The bare-earth surface will contain voids in areas that were densely vegetated, covered

by bridges, buildings, water, fresh asphalt, sand etc.

Conceptual Consistency:

This Light Detection and Ranging (LiDAR) LAS dataset is a topographic survey conducted for the USACE USVI LiDAR Project. These data were

produced for The Corps of Engineers Jacksonville District. The USVI LiDAR Survey consists of the islands of St. Croix, St. Thomas, and

St. John. The LiDAR point cloud was flown at a density sufficient to support the Federal Emergency Management Agency (FEMA) guidelines

and specifications. 3001 Inc. acquired the USVI LiDAR Survey between November 16, 2007 and November 29, 2007. The USVI LiDAR Survey was

collected under the guidance of a Professional Mapper/Surveyor.

Lineage

Sources

The US Virgin Islands LiDAR Survey

CC ID: 1138980
Publish Date: 2008-01-01
Extent Type: Discrete
Extent Start Date/Time: 2008
Scale Denominator: 24000
Source Contribution:

This Light Detection and Ranging (LiDAR) LAS dataset is a topographic survey conducted for the USACE USVI LiDAR Project. These data

were produced for The Corps of Engineers Jacksonville District. The USVI LiDAR Survey consists of the islands of St. Croix, St. Thomas,

and St. John. The LiDAR point cloud was flown at a density sufficient to support the Federal Emergency Management Agency (FEMA)

guidelines and specifications. 3001 Inc. acquired the USVI LiDAR Survey between November 16, 2007 and November 29, 2007. The USVI

LiDAR Survey was collected under the guidance of a Professional Mapper/Surveyor.

| Source Geospatial Form: remote-sensing image | Type of Source Media: digital tape media

Process Steps

Process Step 1

CC ID: 1138981
Description:

The Airborne Global Position System (ABGPS), inertial measurement unit (IMU), and raw scans are collected during the LiDAR aerial survey.

The ABGPS monitors the xyz position of the sensor and the IMU monitors the orientation of the aircraft. During the aerial survey laser

pulses reflected from features on the surface and are detected by the receiver optics and collected by the data logger. GPS locations

are based on data collected by receivers on the aircraft and base stations on the ground. The ground base stations are placed no more

than 35 km radius from the flight survey area.

Process Date/Time: 2007-08-09 00:00:00

Process Step 2

CC ID: 1138982
Description:

The ABGPS, IMU, and raw scans are integrated using proprietary software developed by the Leica Geosystems and delivered with the Leica

ALS50 System. The resultant file is in a LAS binary file format. The LAS file version 1.1 format can be easily transferred from one file

format to another. It is a binary file format that maintains information specific to the LiDAR data (return #, intensity value, xyz, etc.).

The resultant points are produced in the Florida State Plane West Zone coordinate system, with units in feet and referenced to the NAD83

horizontal datum and GRS80/Geoid03 vertical datum.

Process Date/Time: 2008-01-01 00:00:00

Process Step 3

CC ID: 1138983
Description:

The unedited data are classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary

filters is applied as appropriate for the production of bare-earth digital terrain models (DTMs). Interactive editing methods are applied to

those areas where it is inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations

of the relevant filters. These same feature extraction filters are used to produce elevation height surfaces.

Process Date/Time: 2007-08-31 00:00:00

Process Step 4

CC ID: 1138984
Description:

Filtered and edited data are subjected to rigorous QA/QC according to the 3001 Inc. Quality Control Plan and procedures. Very briefly, a

series of quantitative and visual procedures are employed to validate the accuracy and consistency of the filtered and edited data. Ground

control is established by 3001, Inc. and GPS-derived ground control points (GCPs) points in various areas of dominant and prescribed land

cover. These points are coded according to landcover, surface material, and ground control suitability. A suitable number of points are

selected for calculation of a statistically significant accuracy assessment as per the requirements of the National Standard for Spatial

Data Accuracy. A spatial proximity analysis is used to select edited LiDAR data points within a specified distance of the relevant GCPs.

A search radius decision rule is applied with consideration of terrain complexity, cumulative error, and adequate sample size. Accuracy

validation and evaluation is accomplished using proprietary software to apply relevant statistical routines for calculation of Root Mean

Square Error (RMSE) and the National Standard for Spatial Data Accuracy (NSSDA) according to Federal Geographic Data Committee (FGDC)

specifications.

Process Date/Time: 2007-08-31 00:00:00

Process Step 5

CC ID: 1138985
Description:

The LiDAR mass points were delivered in American Society for Photogrammetry and Remote Sensing LAS 1.1 format. The header file for each

dataset is complete as define by the LAS 1.1 specification. In addition the following fields are included: Flight Date Julian, Year, and Class.

The data were classified as follows:

Class 1 = Unclassified- this class includes vegetation, buildings, noise etc.;

Class 2 = Ground

Class 7 = Noise

Class 9 = Water

Class 12 = Overlap

Process Date/Time: 2007-08-31 00:00:00

Process Step 6

CC ID: 1138986
Description:

A triangulated irregular network (TIN) is a set of irregularly spaced points that contain an explicit topographic value. Each point is a

vertice and is connected to any three points to represent an area of uniform topography. TINs retain precise topological location and are

excellent sources for statistical calculations. The TINs were created in Terrasolid's "Terrascan" software. The first step of the process

included the separation of the bare-earth points from the artifacts. The breaklines (vectors) are then concerted to x, y, z (ASCII) files

and imported into the bare-earth mass points. The final step is to create the TIN using an ESRI Arc macro language (aml) script. To ensure

the quality of the TIN each TIN is viewed independently to ensure that the hydro-breaklines are enforced and that the vegetation has been

removed.

Process Date/Time: 2007-01-01 00:00:00

Process Step 7

CC ID: 1138987
Description:

The breaklines were constructed under the model representation that water courses vary linearly in elevation or are constant in elevation

between critical points established in the breakline model. These breaklines were determined from LiDAR and orthophoto data of specific

dates and that model the land/water contributions and extents on those dates. The 3-D vector line work was created using stereo-compilation,

digitizing, and manual editing. A thorough QC procedure was implemented to verify the elevation of the breaklines and to ensure no zero

elevations were found except in coastal areas where it is possible to find z values equal to mean sea level. The breaklines are hydrologically

correct 3-D product that represents a continuous dendritic network. This dataset is topologically correct. Stream and river features

that are 0.5 miles or greater in length will be captured. Features that are 8 feet are less in width shall be captured as a single breaklines.

Features greater than 8 feet in width shall be captured as double breakline features. All features will be captured as three-dimensional

breaklines. Coastal shorelines shall be captured as three-dimensional linear features. Coastal breaklines will merge seamlessly with

linear hydrographic features at the approximate maximum extent of tidal influence. The shoreline of islands within water bodies shall be

captured as three-dimensional breaklines. Terramodel software was used to display the edited LiDAR points and associated GEOTIFF orthophotos

to construct breaklines for the water's edge of wide channel rivers and canals, the shoreline of lakes and the shoreline of islands within

water bodies. Breakline elevations were linearly ramped between identified critical elevation points along flowing water courses or were set

at a fixed level for lakes based on the lowest observed shoreline elevation or water return elevation. The breakline files are edge-matched

and a shapefile for the project was created. Three-dimensional breaklines were derived through on screen digitizing based on the LiDAR data

and orthophotography. The line work was captured as two dimensional lines with x/y coordinates only. Principal breaklines that support

hydrologic and hydraulic models were captured which includes stream shorelines and hydraulic features such as dams, bridges, and culverts

that constrict or impede the flow of water.

Process Date/Time: 2007-01-01 00:00:00

Process Step 8

CC ID: 1138988
Description:

The NOAA Office for Coastal Management (OCM) received files in LAS format. The files contained LiDAR intensity and elevation measurements.

OCM performed the following processing on the data to make it available within Digital Coast:

1. The data were converted from State Plane Puerto Rico coordinates to UTM Zone 20 coordinates.

2. The data were converted from NAVD88 feet to NAVD88 meters.

3. The data were re-tiled in MARS and all point classifications were set to 0 (class 0).

4. The data were filtered to Bare Earth (class 2) and Unclassified (class 1) using an automated process in LASEdit.

5. The data were converted from UTM coordinates to geographic coordinates.

6. The data were converted from NAVD88 heights to ellipsoid heights using Geoid03.

7. The LAS header fields were sorted by latitude and updated.

Process Date/Time: 2010-11-01 00:00:00

Catalog Details

Catalog Item ID: 50067
GUID: gov.noaa.nmfs.inport:50067
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:24+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