Middlesex LiDAR Survey
Table of Contents
IDENTIFICATION_INFORMATION
Citation:
Citation_Information:
Originator: Terrapoint USA
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Edition: One
Geospatial_Data_Presentation_Form: Map
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Other_Citation_Details:
Type Of Scanner = Optech 3100EA
Data Acquisition Height = 1550 meters AGL Scanner
Field Of View = 40 degrees
Scan Frequency = 32.9 Hertz
Pulse Repetition Rate = 71 Kilohertz
Aircraft Speed = 180 Knots
Swath Width = 1128 m
Nominal Ground Sample Distance = 1.37 meters (no overlap)
Number of Returns Per Pulse = 4 (first, last, intermediate)
Distance Between Flight Lines = 564
Format: LAS 1.0
ASPRS Class Code 2=Ground 1=Undefined
Online_Linkage: www.terrapoint.com
Larger_Work_Citation:
Citation_Information:
Originator: Terrapoint USA
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Online_Linkage: www.terrapoint.com
Description:
Abstract:
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. The
LiDAR flightlines for this project was planned for a 50%
acquisition overlap. The nominal resolution of this project
without overlap is 1.37m spacing, but effectively is 2.74m
with overlap factored. Four returns were recorded for each
pulse in addition to an intensity value. GPS Week Time,
Flightline number and scan angle attributes were provided
for each LiDAR point.
Data is provided as random points, in LAS v1.0 format,
classified according to ASPRS Class Code 2=Ground 1=Undefined.
Purpose:
LiDAR data is used to produce high accuracy 3D elevation
based geospatial products.
Supplemental_Information:
First of many pulse and intermediate returns were not
considered in the bare earth ground.
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. is included in the bare earth ground model, except
where the entire tile is covered by water.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20061008
Ending_Date: 20061011
Currentness_Reference: Ground Condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -74.6329
East_Bounding_Coordinate: -74.2015
North_Bounding_Coordinate: 40.6105
South_Bounding_Coordinate: 40.2495
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: LiDAR
Theme_Keyword: LAS_v1.0
Theme_Keyword: OPTECH_3100EA
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Middlesex County
Place_Keyword: New Jersey
Place_Keyword: Northeast
Place_Keyword: United States
Access_Constraints:
Dewberry & Davis LLC has full rights and ownership of this
LiDAR dataset; hence any data requests should be channeled
through Dewberry & Davis LLC.
Use_Constraints:
Any conclusions from results of the analysis of this LiDAR
are not the responsibility of Terrapoint.
The LiDAR data was thoroughly visually verified to
represent the true ground conditions at time of collection.
Users should be aware that temporal changes may have
occurred since the collection of this dataset and some
areas may no longer accurately depict current ground
condition. Users should be aware of the limitations of this
dataset if using for critical applications.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Terrapoint USA
Contact_Person: Claude Vickers
Contact_Position: Production Manager
Contact_Address:
Address_Type: mailing and physical address
Address: 251216 Grogan's Park Drive
City: The Woodlands
State_or_Province: Texas
Postal_Code: 77380
Country: USA
Contact_Voice_Telephone: 1-877-80-TERRA
Contact_Facsimile_Telephone: 1-281-296-0869
Contact_Electronic_Mail_Address: claude.vickers@terrapoint.com
Hours_of_Service: Monday to Friday, 8:30 - 4:30, Eastern Time
Native_Data_Set_Environment:
ArcView version 3.1 shapefile format
x:\storage7\projects\2006_128_u_middlesex_deliverables\shp\midcnb_buffer.shp
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DATA_QUALITY_INFORMATION
Attribute_Accuracy:
Attribute_Accuracy_Report:
Raw elevation measurements have been tested eo 0.87 feet
vertical accuracy at 95 percent confidence level
Logical_Consistency_Report:
All LiDAR files delivered were verified and tested to
ensure they open and are positioned properly.
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 quality control of deliverable products; ensuring
integrity; graphical quality; conformance to Terrapoint
standards are met for all delivered products.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Compiled to meet 3 foot vertical accuracy at the 95 percent
confidence level
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
Tested 0.87 feet vertical accuracy at 95 percent confidence level
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator:
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Edition: One
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Other_Citation_Details:
Online_Linkage: www.terrapoint.com
Larger_Work_Citation:
Citation_Information:
Originator: Terrapoint USA
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Online_Linkage: www.terrapoint.com
Source_Scale_Denominator: unknown
Type_of_Source_Media: Hard Drive
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20061006
Ending_Date: 20061115
Source_Currentness_Reference: unknown
Source_Citation_Abbreviation:
Source_Contribution:
LiDAR data representing Middlesex County
Source_Information:
Source_Citation:
Citation_Information:
Originator:
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Edition: One
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Other_Citation_Details:
Online_Linkage: www.terrapoint.com
Larger_Work_Citation:
Citation_Information:
Originator: Terrapoint USA
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Online_Linkage: www.terrapoint.com
Source_Scale_Denominator: unknown
Type_of_Source_Media: Hard Drive
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20061006
Ending_Date: 20061115
Source_Currentness_Reference: unknown
Source_Citation_Abbreviation:
Source_Contribution:
LiDAR data representing Middlesex County
Source_Information:
Source_Citation:
Citation_Information:
Originator:
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Edition: One
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Other_Citation_Details:
Online_Linkage: www.terrapoint.com
Larger_Work_Citation:
Citation_Information:
Originator: Terrapoint USA
Publication_Date: 20061115
Title: Middlesex LiDAR Survey
Publication_Information:
Publication_Place: Houston, Texas
Publisher: Terrapoint USA
Online_Linkage: www.terrapoint.com
Source_Scale_Denominator: unknown
Type_of_Source_Media: Hard Drive
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20061006
Ending_Date: 20061115
Source_Currentness_Reference: unknown
Source_Citation_Abbreviation:
Source_Contribution:
LiDAR data representing Middlesex County
Process_Step:
Process_Description:
General Overview
The Airborne LiDAR survey was conducted using an OPTECH
3100EA flying at a nominal height of 1550 metres AGL with a
total angular coverage of 40 degrees. Flight line spacing
was nominally 564 metres, providing overlap of 50% on
adjacent flight lines. All of the lines were flown in a
north/south direction for the project. Aircraft
A Piper Navajo, registration C-GPJT, was used for the
survey. This aircraft has a flight range of approximately
4.5 hours and was flown at an average altitude of 1550
metres AGL (Above Ground Level), thereby encountering
flying altitudes of approximately 1550 metres above Mean
Sea Level (MSL). The aircraft was staged from the Linden NJ
Airport, and ferried daily to the project site for flight
operations.
GPS Receivers
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. Number
of Flights and Flight Lines
A total of 4 missions were flown for this project with
flight times ranging approximately 16.25 hours under good
meteorological and GPS conditions. 55 flight lines were
flown over the project area to provide complete coverage.
Lines were flown at 564 metre spacing to achieve 50%
lateral overlap.
Source_Used_Citation_Abbreviation: Acquisition Process
Process_Date: 200610
Source_Produced_Citation_Abbreviation: ACQ
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Organization: Terrapoint USA
Contact_Person: Claude Vickers
Contact_Position: Production Manager
Contact_Address:
Address_Type: mailing and physical address
Address: 251216 Grogan's Park Drive
City: The Woodlands
State_or_Province: Texas
Postal_Code: 77380
Country: USA
Contact_Voice_Telephone: 1-877-80-TERRA
Contact_Facsimile_Telephone: 1-281-296-0869
Contact_Electronic_Mail_Address: claude.vickers@terrapoint.com
Hours_of_Service: Monday to Friday, 8:30 - 4:30, Eastern Time
Process_Step:
Process_Description:
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 4.5. Distances from
base station to aircraft were kept to a maximum of 35 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 5cm average but no larger than 8 cm
being recorded. Calculation
of 3D laser points (raw data)
The post-processing software to derive X, Y, Z values from
roll, pitch, yaw, and range is Optech's Realm. Data
Classification and Editing
The data was processed using the software TerraScan, and
following the methodology described herein. The initial
step is the setup of the TerraScan project, which is done
by importing client provided tile boundary index
encompassing the entire project areas. The 3D laser point
clouds, in binary format, were imported into the TerraScan
project and divided in 425 tiles, as per the contract
specifications. 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 is 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 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.
Projection Transformation
The data was processed in the native UTM zone in meters and
then transformed to the New Jersey State Plane final
projection system and US survey feet using an in-house
transformation software which uses the Coorpscon DLL.
Source_Used_Citation_Abbreviation: Data Processing
Process_Date: 200611
Source_Produced_Citation_Abbreviation: PRD
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Organization: Terrapoint USA
Contact_Person: Claude Vickers
Contact_Position: Production Manager
Contact_Address:
Address_Type: mailing and physical address
Address: 251216 Grogan's Park Drive
City: The Woodlands
State_or_Province: Texas
Postal_Code: 77380
Country: USA
Contact_Voice_Telephone: 1-877-80-TERRA
Contact_Facsimile_Telephone: 1-281-296-0869
Contact_Electronic_Mail_Address: claude.vickers@terrapoint.com
Hours_of_Service: Monday to Friday, 8:30 - 4:30, Eastern Time
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SPATIAL_DATA_ORGANIZATION_INFORMATION
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 1
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SPATIAL_REFERENCE_INFORMATION
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: New Jersey
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999900
Longitude_of_Central_Meridian: -74.500000
Latitude_of_Projection_Origin: 38.833333
False_Easting: 492124.999950
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: Coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.01
Ordinate_Resolution: 0.01
Planar_Distance_Units: US Survey Feet
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: GRS 80
Semi-major_Axis: 20925604.4720406
Denominator_of_Flattening_Ratio: 298.26
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum of 1988
Altitude_Resolution: 0.01
Altitude_Distance_Units: US Survey Feet
Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates
Depth_System_Definition:
Depth_Datum_Name:
Depth_Resolution:
Depth_Distance_Units:
Depth_Encoding_Method:
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ENTITY_AND_ATTRIBUTE_INFORMATION
Overview_Description:
Entity_and_Attribute_Overview:
LiDAR point data in LAS 1.0 format
ASPRS cassfication scheme (1 = undefined; 2 = ground)
Contains the following 10 fields of information:
GPS WeekTime
Easting Angle (integer)
Echo Number
Echo
Entity_and_Attribute_Detail_Citation:
none
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DISTRIBUTION_INFORMATION
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Terrapoint USA
Contact_Person: Claude Vickers
Contact_Position: Production Manager
Contact_Address:
Address_Type: mailing and physical address
Address: 251216 Grogan's Park Drive
City: The Woodlands
State_or_Province: Texas
Postal_Code: 77380
Country: USA
Contact_Voice_Telephone: 1-877-80-TERRA
Contact_Facsimile_Telephone: 1-281-296-0869
Contact_Electronic_Mail_Address: claude.vickers@terrapoint.com
Hours_of_Service: Monday to Friday, 8:30 - 4:30, Eastern Time
Resource_Description:
The LiDAR data was captured for Dewberry & Davis for flood
plain mapping purposes
Distribution_Liability:
Users must assume responsibilty to determine the
appropriate use of this LiDAR dataset.
The LiDAR has been compiled to 3 foot vertical accuracy;
tested to 0.87 feetvertical accuracy at 95 percent
confidence level.
Data is representative of ground conditions at time of
acquisition only.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name:LAS 1.0
Digital_Transfer_Option:
Offline_Option:
Offline_Media: DVD, HD
Recording_Format: Standard
Compatibility_Information:
none
Fees: Current Handling and Processing Terrapoint Fees
Ordering_Instructions:
Proper release required from Dewberry & Davis LLC for
orders outside of Dewberry & Davis LLC.
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METADATA_REFERENCE_INFORMATION
Metadata_Date: 20070227
Metadata_Review_Date:
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Terrapoint USA
Contact_Person: Claude Vickers
Contact_Position: Production Manager
Contact_Address:
Address_Type: Mailing and physical address
Address: 251216 Grogan's Park Drive
City: The Woodlands
State_or_Province: Texas
Postal_Code: 77380
Country: USA
Contact_Voice_Telephone: 1-877-80-TERRA
Contact_Facsimile_Telephone: 1-281-296-0869
Contact_Electronic_Mail_Address: claude.vickers@terrapoint.com
Hours_of_Service: Monday to Friday, 8:30 - 4:30, Eastern Time
Metadata_Standard_Name: FGDC CSDGM
Metadata_Standard_Version: FGDC-STD-001-1998
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