Slide Menu
Search Help Show/Hide Menu
Short Citation:
OCM Partners, 2023: 2007 Florida Division of Emergency Management (FDEM) Lidar Project: Nassau County,

Item Identification

Title: 2007 Florida Division of Emergency Management (FDEM) Lidar Project: Nassau County
Short Name: fl2007_fdem_nassau_m557_metadata
Status: Completed
Publication Date: 2008

This report pertains to a Specific Purpose LiDAR Survey of Nassau County, Florida. The LiDAR aerial acquisition was conducted by Terrapoint USA

between August 18, 2007 and September 4, 2007, and the breaklines and contours were subsequently generated by Dewberry. The PDS team is under

contract HS-34-14-00-22-469 with the Florida Division of Emergency Management (FDEM) and offered LiDAR and derived products as an add-on

agreement with Nassau County at the same rates as negotiated for the FDEM contract and utilizing the same Baseline Specifications from FDEM.

The LiDAR dataset of Nassau County was acquired by Terrapoint USA and processed to a bare-earth digital terrain model (DTM) in accordance with FDEM

Baseline Specifications. Detailed breaklines and contours were also produced by the PDS team. Each tile covers an area of 5000 ft by 5000 ft.

The FDEM Baseline Specifications require a maximum LiDAR post spacing of 4 feet, i.e., an average point density of less than 1 point per square meter.

However, the PDS team required a much higher point density of its subcontractors in order to increase the probability of penetrating dense foliage;

with nominal post spacing of 0.7 meters per flight line and 50% sidelap between flight lines, the average point density is 4 points per square meter

with higher point density there is a greater probability of penetrating dense vegetation and minimizing areas defined as "low confidence areas."

LiDAR was delivered as a point cloud in LAS 1.1 format.

Original contact information:

Contact Org: Florida DEM

Phone: 850-413-9907



These data support the Florida Division of Emergency Management's (FDEM) development and maintenance of Regional Evacuation Studies, which include

vulnerability assessments and assist disaster response personnel in understanding threats to Florida's citizens and visitors.



Supplemental Information:

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

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
Data Presentation Form: Map (digital)
Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of the Office for Coastal Management

or its partners.

Support Roles

Data Steward

CC ID: 672659
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:
Phone: (843) 740-1202


CC ID: 672661
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:
Phone: (843) 740-1202

Metadata Contact

CC ID: 672662
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:
Phone: (843) 740-1202

Point of Contact

CC ID: 672660
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:
Phone: (843) 740-1202


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1138961
W° Bound: -84.748761
E° Bound: -84.083288
N° Bound: 30.306119
S° Bound: 29.962468

Extent Group 1 / Time Frame 1

CC ID: 1138960
Time Frame Type: Range
Start: 2007-08-18
End: 2007-10-04

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
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: 740760
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: 740761
Download URL:
File Name: Bulk Download

Simple download of data files.



CC ID: 740763
URL Type:
Online Resource


CC ID: 740764
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 672675
Activity Date/Time: 2016-05-23

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 672674
Activity Date/Time: 2017-11-14

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

Activity Log 3

CC ID: 718238
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 740762
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Technical Environment


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

Data Quality

Horizontal Positional Accuracy:

Lidar source compiled to meet 1m horizontal accuracy.

; Quantitative Value: 1 meters, Test that produced the value:

The PDS team does not perform independent horizontal accuracy testing on the Lidar. Lidar vendors perform calibrations on the Lidar sensor and

compare data to adjoing flight lines to ensure Lidar meets the 1 meter horizontal accuracy standard at the 95% confidence level.

Vertical Positional Accuracy:

The LiDAR is required to meet 0.60 feet Fundamental Vertical Accuracy (FVA) and 1.19 feet Consolidated Vertical Accuracy (CVA).

; Quantitative Value: 0.183 meters, Test that produced the value:

Based on the vertical accuracy testing conducted by PDS, using NSSDA and FEMA guidelines, vertical accuracy at the 95% confidence level

(called Accuracyz) is computed by the formula RMSEz x 1.9600. The dataset for Nassau County, Florida satisfies the criteria:

Countywide lidar dataset tested 0.60 feet (18.3 cm) vertical accuracy at 95% confidence level in open terrain, based on open terrain RMSEz (0.31') x 1.9600.

Countywide lidar dataset tested 0.98 feet (29.4 cm) vertical accuracy at 95% confidence level in all land cover categories combined, based on consolidated

RMSEz (0.50') x 1.9600.

Completeness Report:

A visual qualitative assessment was performed to ensure the data completness against the intensity images derived from Lidar points.

No void or missing data.

Conceptual Consistency:

Data covers the tile scheme provided for the county.




CC ID: 1138955
Publish Date: 2007-01-01
Extent Type: Range
Extent Start Date/Time: 2007-08-18
Extent End Date/Time: 2007-10-15
Source Contribution:

LiDAR dataset was used to create intensity stereopairs for 3D breakline compilation and for contour generation. | Source Geospatial Form: vector digital data | Type of Source Media: online

Process Steps

Process Step 1

CC ID: 1138956

The ABGPS, IMU, and raw Optech 3100ea LiDAR scans are integrated using Optech Incorporated's DASHMap, version 1.1 software, Terrascan software and

Microstation software. 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 referenced to the NAD83 horizontal datum and GRS80 vertical datum. The date and time for each flight line can be

determined using the Julian date and time. The Julian date is a continuous count of days and fractions since noon Universal Time on January 1, 4713

BCE on the Julian Calendar.

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

Process Step 2

CC ID: 1138957

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

are 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. 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 (Precision reported in brackets): Class (Integer); GPS Week Time (0.0001 seconds); Easting (0.01 meter);

Northing (0.01 meter); Elevation (0.01 meter); Echo Number (Integer 1 to 4); Echo (Integer 1 to 4); Intensity (8 Bit Integer); Flightline

(Integer); Scan Angle (Integer Degree). The LAS files do not include overlap.

The data was classified as follows:

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

Class 2 = Ground

Class 7 = Noise

Class 9 = Water

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

Process Step 3

CC ID: 1138958

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 projected in Florida State Plane Coordinates (East Zone, NAD83/HARN), and referenced to the orthometric datum of NAVD88 utilizing Geoid 03.

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

1. The data were converted from State Plane Coordinates (NAD83/HARN) coordinates to geographic coordinates (NAD83).

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: 2010-10-20 00:00:00

Child Items

Rubric scores updated every 15m

Rubric Score Type Title
Entity LAS

Catalog Details

Catalog Item ID: 49689
GUID: gov.noaa.nmfs.inport:49689
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