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Data Set Info
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Spatial Info
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Lineage
Catalog Details

Summary

Browse Graphic

Short Citation
OCM Partners, 2024: 2011 Delaware Department of Natural Resources and Environmental Control (DNREC) Lidar: Bombay Hook National Wildlife Refuge, https://www.fisheries.noaa.gov/inport/item/49661.
Full Citation Examples

Abstract

Terrapoint collected LiDAR for over 177 square kilometers of the Bombay Hook National Wildlife Refuge in Kent County, Delaware.

The nominal pulse spacing for this project was no greater than 0.75 meters. This project was collected with a sensor which collects

waveform data and provides an intensity value for each discrete pulse extracted from the waveform. GPS Week Time, Intensity, Flightline

and echo number attributes were provided for each LiDAR point. Dewberry used proprietary procedures to classify the LAS according to

project specifications: 1-Unclassified, 2-Ground, 7-Noise, 9-Water, 12-Overlap. Once the data was received by NOAA OCM, all of the

class 7 (noise) points were removed from the data set. Dewberry produced classified LAS and DEMs for the 99 tiles (1700 m x 1700 m) that

cover the project area.

Original contact information:

Contact Org: NOAA Office for Coastal Management

Phone: 843-740-1202

Email: coastal.info@noaa.gov

Distribution Information

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

  • Simple download of data files.

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

elevation

Child Items

No Child Items for this record.

Contact Information

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

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

Extents

Geographic Area 1

-75.530873° W, -75.389419° E, 39.309361° N, 39.046286° S

Time Frame 1
2011-04-18 - 2011-04-20

Item Identification

Title: 2011 Delaware Department of Natural Resources and Environmental Control (DNREC) Lidar: Bombay Hook National Wildlife Refuge
Short Name: de2011_bombay_hook_m1172_metadata
Status: Completed
Publication Date: 2012-04
Abstract:

Terrapoint collected LiDAR for over 177 square kilometers of the Bombay Hook National Wildlife Refuge in Kent County, Delaware.

The nominal pulse spacing for this project was no greater than 0.75 meters. This project was collected with a sensor which collects

waveform data and provides an intensity value for each discrete pulse extracted from the waveform. GPS Week Time, Intensity, Flightline

and echo number attributes were provided for each LiDAR point. Dewberry used proprietary procedures to classify the LAS according to

project specifications: 1-Unclassified, 2-Ground, 7-Noise, 9-Water, 12-Overlap. Once the data was received by NOAA OCM, all of the

class 7 (noise) points were removed from the data set. Dewberry produced classified LAS and DEMs for the 99 tiles (1700 m x 1700 m) that

cover the project area.

Original contact information:

Contact Org: NOAA Office for Coastal Management

Phone: 843-740-1202

Email: coastal.info@noaa.gov

Purpose:

The purpose of this LiDAR data was to produce high accuracy 3D elevation products, including tiled LiDAR in LAS 1.2 format and 1 m cell

size Digital Elevation Models (DEMs) for use in coastal management. The LiDAR are processed to the specifications outlined by NOAA OCM

in partnership with the Delaware Department of Natural Resources and Environmental Control (DNREC).

Notes:

10305

Supplemental Information:

The Lidar Project Final Report for this data set may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1172/supplemental/FinalProjectReport_BombayHook_07062011.pdf

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

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1172/supplemental/2011_DNREC_Bombay_Hook_National_Wildlife_Refuge_Lidar.kmz

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Entity Attribute Overview:

LiDAR points in LAS 1.2 format

Entity Attribute Detail Citation:

none

Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of DNREC, the Office for Coastal Management or its partners.

Support Roles

Data Steward

CC ID: 671733
Date Effective From: 2012-04
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: 671735
Date Effective From: 2012-04
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: 671736
Date Effective From: 2012-04
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: 671734
Date Effective From: 2012-04
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: 1132831
W° Bound: -75.530873
E° Bound: -75.389419
N° Bound: 39.309361
S° Bound: 39.046286

Extent Group 1 / Time Frame 1

CC ID: 1132830
Time Frame Type: Range
Start: 2011-04-18
End: 2011-04-20

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/#/lidar/search/where:ID=1172

This data set is dynamically generated based on user-specified parameters.

;

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: 740612
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=1172
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: 740613
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1172/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 740615
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 740616
URL: https://coast.noaa.gov
URL Type:
Online Resource

URL 3

CC ID: 740617
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1172/supplemental/2011_DNREC_Bombay_Hook_National_Wildlife_Refuge_Lidar.kmz
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic shows the lidar coverage for the Bombay Hook National Wildlife Refuge data set.

Activity Log

Activity Log 1

CC ID: 671752
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 671751
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: 718209
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 740614
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 3; ESRI ArcCatalog 9.3.1.1850

Data Quality

Horizontal Positional Accuracy:

Lidar source compiled to meet 1 meter horizontal accuracy.; Quantitative Value: 1 meters, Test that produced the value:

Dewberry does not perform independent horizontal accuracy testing on the LiDAR. LiDAR vendors perform calibrations on the LiDAR sensor

and compare data to adjoining flight lines to ensure LiDAR meets the 1 m horizontal accuracy standard at the 95% confidence level.

Vertical Positional Accuracy:

The vertical accuracy of the LiDAR was tested by Dewberry with 8 independent survey checkpoints. The survey checkpoints were evenly

distributed throughout the project area. All 8 checkpoints were used to compute the Fundamental Vertical Accuracy (FVA). Project

specifications required a FVA of 18 cm (0.18 m) based on an RMSEz (9 cm/ 0.09 m) x 1.9600. All checkpoints were also used to compute

the Consolidated Vertical Accuracy (CVA). Project specifications required a CVA of 18 cm (0.18 m) based on the 95th percentile.

; Quantitative Value: 0.07 meters, Test that produced the value:

RMSE is 7 cm. Based on the vertical accuracy testing conducted by Dewberry, using NSSDA and FEMA methodology, vertical accuracy at

the 95% confidence level (called Accuracyz) is computed by the formula RMSEz x 1.9600. The dataset for the Bombay Hook project satisfies

the criteria: Lidar dataset tested 0.14 m vertical accuracy at 95% confidence level, based on RMSEz (0.07 m) x 1.9600.

Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, consolidated vertical accuracy at the

95% confidence level is computed using the 95th percentile method. The dataset for the Bombay Hook project satisfies the criteria:

Lidar dataset tested 0.11 m vertical accuracy at 95% confidence level in all land cover categories combined.

Completeness Report:

A visual qualitative assessment was performed to ensure data completeness and compliance with project specifications. No void or missing

data exists. Multiple tiles were added to the tile grid to fully cover the project boundary. While the boundary intersects two of these

tiles (582a and 601a), this area is water and there are no LiDAR points in these tiles. The bare earth surface passes vertical accuracy

specifications.

Conceptual Consistency:

Data covers the tile scheme provided for the project area.

Lineage

Process Steps

Process Step 1

CC ID: 1132826
Description:

Terrapoint used their Optech ALTM 3100EA LiDAR sensor to collect the data for the Bombay Hook project.

Three flight missions were required to obtain data over the entire project area. Flightlines were flown in a North-South orientation to

optimize flying time in regards to the project layout. A combination of Sokkia GSR 2600 and NovAtel DL-4+ dual-frequency GPS receivers

were used to support the airborne operations of this survey and to establish the GPS control network. Terrapoint used three existing

published survey monuments and one newly established control station to control all flight missions and kinematic and static ground

surveys.

Airborne GPS kinematic data was processed on-site using GrafNav kinematic On-The-Fly (OTF) software. Flights were flown with a minimum

of 6 satellites in view (13 degrees above the horizon) and with a PDOP of better than 4. Distances from base station to aircraft were

kept to a maximum of 40 km. For all flights, the GPS data can be classified as excellent, with GPS residuals of 3 cm average or better

but no larger than 10 cm being recorded.

The initial step of calibration is to verify availability and status of all needed GPS and Laser data against field notes and compile

any data if not complete. Subsequently the mission points are output using Optech's Dashmap, initially with default values from Optech

or the last mission calibrated for system. The initial point generation for each mission calibration is verified within

Microstation/Terrascan for calibration errors. If a calibration error greater than specification is observed within the mission,

the roll pitch and scanner scale corrections that need to be applied are calculated. The missions with the new calibration values are

regenerated and validated internally once again to ensure quality. All missions are validated against the adjoining missions for relative

vertical biases and collected GPS kinematic validation points for absolute vertical accuracy purposes. On a project level, a supplementary

coverage check is carried out, to ensure no data voids unreported by Field Operations are present.

Process Date/Time: 2011-04-01 00:00:00

Process Step 2

CC ID: 1132827
Description:

Dewberry utilizes a variety of software suites for inventory management, classification, and data processing. All LiDAR related processes

begin by importing the data into the GeoCue task management software. The swath data is tiled into the client provided tiling schema

(1700 m x 1700 m). The tiled data is then opened in Terrascan where Dewberry uses proprietary ground classification routines to remove

any non-ground points and generate an accurate ground surface. The first part of the ground routine is to classify all points with a scan

angle greater than 20 degrees to class 12, overlap. These points have the highest potential to cause issues in the ground surface.

Therefore, they are classified to class 12 immediately where they will not be available for the remaining ground routine. The ground

routine consists of three main parameters (building size, iteration angle, and iteration distance); by adjusting these parameters and

running several iterations of this routine an initial ground surface is developed. The building size parameter sets a roaming window size.

Each tile is loaded with neighboring points from adjacent tiles and the routine classifies the data section by section based on this

roaming window size. The second most important parameter is the maximum terrain angle, which sets the highest allowed terrain angle within

the model. The ground routine also identifies extremely low or high points that should be excluded from the ground surface and classifies

them as class 7, noise. Once the ground routine has been completed a manual quality control routine is done using hillshades,

cross-sections, and profiles within the Terrasolid software suite. After this QC step, a peer review and supervisor manual inspection

is completed on a percentage of the classified tiles based on the project size and variability of the terrain. After the ground

classification corrections were completed, the dataset was processed through a water classification routine that utilizes breaklines

compiled by Dewberry to automatically classify hydrographic features. The water classification routine selects ground points within the

breakline polygons and automatically classifies them as class 9, water. The fully classified dataset is then processed through

Dewberry's comprehensive quality control program.

The data was classified as follows:

Class 1 = Unclassified. This class includes vegetation, buildings, noise etc.

Class 2 = Ground

Class 7= Noise (These points were removed from the data set by NOAA OCM during processing for data storage and Digital Coast provisioning).

Class 9 = Water

Class 12= Overlap Points with a scan angle greater than 20 degrees

The LAS header information was verified to contain the following:

Class (Integer)

GPS Week Time (0.0001 seconds)

Easting (0.01 foot)

Northing (0.01 foot)

Elevation (0.01 foot)

Echo Number (Integer 1 to 4)

Echo (Integer 1 to 4)

Intensity (8 bit integer)

Flight Line (Integer) Scan Angle (Integer degree)

Process Date/Time: 2011-05-01 00:00:00

Process Step 3

CC ID: 1132828
Description:

The NOAA Office for Coastal Management (OCM) received the files in las format. The files contained LiDAR elevation as well as intensity

values. The data were in Delaware State Plane, NAD83 coordinates and NAVD88 heights. OCM performed the following processing for data

storage and Digital Coast provisioning purposes:

1. The data were converted from Delaware State Plane, NAD83 coordinates to geographic coordinates.

2. The data were converted from NAVD88 heights to ellipsoid heights using Geoid09.

3. Data points that were classified as 7 (noise) were removed from the data set.

4. The data were sorted and converted to LAZ format.

Process Date/Time: 2012-04-01 00:00:00

Catalog Details

Catalog Item ID: 49661
GUID: gov.noaa.nmfs.inport:49661
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:21+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