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OCM Partners, 2023: 2007 FEMA New Jersey Flood Mitigation Lidar: Gloucester County,

Item Identification

Title: 2007 FEMA New Jersey Flood Mitigation Lidar: Gloucester County
Short Name: nj2007_gloucester_m544_metadata
Status: Completed
Publication Date: 2007-11-23

LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. By positioning laser range

finding with the use of 1 second GPS with 100hz inertial measurement unit corrections, Terrapoint's LIDAR instruments are able to make

highly detailed geospatial elevation products of the ground, man-made structures and vegetation. These data were collected from

March 29 - April 6, 2007 for Gloucester County, New Jersey. The project area covers 353 square miles. The LiDAR flightlines for this

project were planned for a 50% acquisition overlap. The nominal resolution of this project without overlap is 1.25 m. Four returns were

recorded for each pulse in addition to an intensity value. GPS Week Time, Intensity, Flightline and number attributes were provided for

each LiDAR point. Data is provided as random points, in LAS v1.1 format, classified according to the following ASPRS Class Codes:

Class 1 - Non-ground

Class 2 - Ground

Class 7 - Noise

Class 9 - Water

Original contact information:

Contact Name: Claude Vickers

Contact Org: Terrapoint USA

Title: Production Manager

Phone: 1-877-80-TERRA



The purpose of this LiDAR data was to produce high accuracy 3D elevation based geospatial products for floodplain mapping for

Gloucester County, New Jersey.



Supplemental Information:

Please note that the LiDAR intensity is not calibrated or normalized. The intensity value is meant to provide relative signal

return strengths for features imaged by the sensor. Water is not included in the bare earth ground model, rather it is classified

as water on Class 9. Water body delineation was collected using hillshades, intensity and cross-sections from the LiDAR. In the event

of multiple tides from overlapping missions only the lowest tide was included for the water; nor were the peaks of tall waves;

all remaining points within the water body were classified to class 1.

The Lidar QA/QC Quantitative and Qualitative Assessment Report for this data set may be viewed at:

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


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
None ASPRS standards
None OPTECH_3100EA

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 NOAA,

the Office for Coastal Management or its partners.

Support Roles

Data Steward

CC ID: 680656
Date Effective From: 2007-11-23
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 680658
Date Effective From: 2007-11-23
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Metadata Contact

CC ID: 680659
Date Effective From: 2007-11-23
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Point of Contact

CC ID: 680657
Date Effective From: 2007-11-23
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1138831
W° Bound: -75.45065
E° Bound: -74.862458
N° Bound: 39.888795
S° Bound: 39.504954

Extent Group 1 / Time Frame 1

CC ID: 1138830
Time Frame Type: Range
Start: 2007-03-29
End: 2007-04-06

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:;

Data Access Constraints:


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: 741730
Download URL:
File Name: Customized Download

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

Distribution 2

CC ID: 741731
Download URL:
File Name: Bulk Download

Simple download of data files.

Activity Log

Activity Log 1

CC ID: 680678
Activity Date/Time: 2016-05-23

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 680677
Activity Date/Time: 2017-11-14

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

Activity Log 3

CC ID: 718435
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 741732
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Technical Environment


ArcView version 3.1 shapefile format

Data Quality


Raw elevation measurements have been tested to 0.181 m Fundamental Vertical Accuracy (FVA) at 95% confidence level.

Horizontal Positional Accuracy:

Compiled to meet 1 m vertical accuracy at the 95% confidence level.

Vertical Positional Accuracy:

Tested to 0.181 m Fundamental Vertical Accuracy (FVA) at the 95% confidence level.

Completeness Report:

According to Terrapoint standards; the following aspects of the LiDAR data was verified during the course of the project processing:

-Data completeness and integrity,

-Data accuracy and errors,

-Anomaly checks through full-feature hillshades,

-Post automated classification Bare-earth verification,

-RMSE inspection of final bare-earth model using kinematic GPS,

-Final quality control of deliverable products; ensuring integrity; graphical quality; conformance to Terrapoint standards are met

for all delivered products.

Conceptual Consistency:

All LiDAR files delivered were verified and tested to ensure they open and are positioned properly.



Gloucester County, New Jersey FEMA Flood Mitigation LiDAR

CC ID: 1138825
Publish Date: 2007-11-23
Extent Type: Range
Extent Start Date/Time: 2007-03-29
Extent End Date/Time: 2007-04-06
Citation URL:
Source Contribution:

LiDAR data Gloucester County, New Jersey FEMA Flood Mitigation LiDAR | Source Geospatial Form: map | Type of Source Media: Hard Drive

Process Steps

Process Step 1

CC ID: 1138826

General Overview:

Project Area = 874 square kilometers, Type of Scanner = Optech 3100EA, Number of Scanners = 1, Data Acquisition Height = 1550 meters,

AGL Scanner Field of View = 46 degrees, The scan frequency = 30 Hertz, Pulse Repetition Rate = 71 Kilohertz, Aircraft Speed = 150 Knots,

Swath Width = 1315 m, Nominal Ground Sample Distance = 1.25 meters - no overlap, Number of Returns Per Pulse = 4, Distance Between

Flight Lines = 658 m, The Airborne LiDAR survey was conducted using one OPTECH 3100EA system flying at a nominal height of

1550 metres AGL, a total angular coverage of 46 degrees. Flight line spacing nominally 658 meters providing overlap of 50% on adjacent

flight lines. Lines were flown in NE/SW to best optimize flying time considering the layout for the project. The aircraft used for this

survey was a Piper Navajo, registration C-GPJT. This aircraft has a flight range of approximately 6 hours and was flown at an average

altitude of 1550 meters above ground level (AGL). The aircraft was staged from the Millville Airport and ferried daily to the project

site for flight operations.

GPS Receivers:

A combination of Sokkia GSR 2600 and Applanix POSAv-510 dual frequency GPS receivers were used to support the airborne operations of

this survey and to establish the GPS control network.

Number of Flights and Flight Lines:

A total of 8 missions were flown for this project with flight time ranging approximately 15 hours under good meteorological and GPS

conditions. 76 flight lines were flown over the project site to provide complete coverage.

Reference Coordinate System Used Existing NGS (National Geodetic Survey) monuments were observed in a GPS control network to establish

1 new station(s): Station_ID: 128U-01128U-01 was used as primary control for the project flight missions and kinematic ground surveys.

The published horizontal datum of the NGS stations is NAD83 and the vertical datum NAVD88. The following are the final coordinates

of the newly established control points used in this project: Station_ID: 128U-01, West_Longitude: 75 09 04.89385,

North_Latitude: 39 43 09.54246, Ellips_Elev: 14.761 m,

Geoid Model Used: The Geoid03 geoid model, published by the NGS, was used to transform all ellipsoidal heights to orthometric.

Process Date/Time: 2007-04-01 00:00:00

Process Step 2

CC ID: 1138827

Airborne GPS Kinematic

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 (13o above the horizon) and with a PDOP of better than 3.5. Distances from base station to aircraft were kept

to a maximum of 30 km, to ensure a strong OTF (On-The-Fly) solution. For all flights,the GPS data can be classified as excellent,

with GPS residuals of 5 cm average but no larger than 10 cm being recorded.

Generation and Calibration of laser points (raw data)

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 ground truthing points for absolute vertical accuracy purposes. On a project level, a

coverage check is carried out to ensure no slivers are present.

Data Classification and Editing

The data was processed using the software TerraScan, and followed the methodology described herein. The initial step is the setup of

the TerraScan project, which is done by importing client provided tile boundary index (converted to the native UTM zone for processing)

encompassing the entire project areas. The 3D laser point clouds, in binary format, were imported into the TerraScan project and

divided in 440 tiles in LAS 1.0 format. Once tiled, the laser points were classified using a proprietary routine in TerraScan. This

routine removes any obvious outliers from the dataset following which the ground layer is extracted from the point cloud. The ground

extraction process encompassed in this routine takes place by building an iterative surface model. This surface model is generated

using three main parameters: building size, iteration angle and iteration distance. The initial model is based on low points being

selected by a "roaming window" with the assumption that these are the ground points. The size of this roaming window is determined

by the building size parameter. The low points are triangulated and the remaining points are evaluated and subsequently added to the

model if they meet the iteration angle and distance constraints. This process is repeated until no additional points are added within

an iteration. A second critical parameter is the maximum terrain angle constraint,which determines the maximum terrain angle allowed

within the classification model. The data is then manually quality controlled with the use of hillshading, cross-sections and profiles.

Any points found to be of class vegetation, building or error during the quality control process, are removed from the ground model and

placed on the appropriate layer. An integrity check is also performed simultaneously to verify that ground features such as rock cuts,

elevated roads and crests are present. Once data has been cleaned and complete, it is then reviewed by a supervisor via manual

inspection and through the use of a hillshade mosaic of the entire project area.

Deliverable Tiling Scheme

All files were converted to LAS 1.1, in the specified projection and units and were delivered in the client provided tiling scheme

with a total of 440 tiles.

Process Date/Time: 2007-11-01 00:00:00

Process Step 3

CC ID: 1138828

The NOAA Office for Coastal Management (OCM) received the files in las format. The files contained Lidar elevation and intensity measurements.

The data were in New Jersey State Plane projection, and NAVD88 Geoid 03 vertical datum.OCM performed the following processing to the

data to make it available within the Digital Coast:

1. The data were converted from New Jersey State Plane coordinates to geographic coordinates.

2. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03.

3. The LAS data were sorted by latitude and the headers were updated.

Process Date/Time: 2010-08-01 00:00:00

Catalog Details

Catalog Item ID: 49856
GUID: gov.noaa.nmfs.inport:49856
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:22+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