Short Citation:
OCM Partners, 2021: 2009 Chatham County Georgia Lidar, https://www.fisheries.noaa.gov/inport/item/49725.

Item Identification

Title: 2009 Chatham County Georgia Lidar
Short Name: ga2009_chatham_m1121_metadata
Status: Completed
Publication Date: 2012-01
Abstract:

LiDAR generated point cloud acquired in spring 2009 for Chatham County, Georgia for the Metropolitan Planning Commission.

The data are classified as follows:

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

Class 2 = Ground

Class 9 = Water

This data is for planning purposes only and should not be used for legal or cadastral purposes.

Original contact information:

Contact Name: Noel Perkins

Contact Org: SAGIS

Title: Director

Phone: 912-651-1476

Email: perkinsn@thempc.org

Purpose:

LiDAR points used in conjunction with LiDAR derived breaklines to determine a DTM surface.

Notes:

10370

Supplemental Information:

Support of FEMA's Floodplain Map Modernization Program and Florida Division of Emergency Management Disaster standards.

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

https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/1121/supplemental/2009_Chatham_County_Georgia_Lidar.kmz

Keywords

Theme Keywords

Thesaurus Keyword
UNCONTROLLED
ISO 19115 Topic Category elevation
None Bathymetry/Topography
None DTM
None Elevation
None Lidar

Spatial Keywords

Thesaurus Keyword
UNCONTROLLED
None Chatham County
None Georgia
None United States

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: Unknown
Entity Attribute Overview:

ASPRS LAS Point Record Entries - binary data recorded for each point

Entity Attribute Detail Citation:

ASPRS LAS attributes

Distribution Liability:

The data represent the results of data collection and processing for a specific Metropolitan Planning

Commission activity and indicates the general existing conditions at the time of the data collection. As such, it is only valid for

its intended use, content, time, and accuracy specifications. The user is responsible for the results of any application of the data

for other than its intended purpose. 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: 674276
Date Effective From: 2012-01
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: 674278
Date Effective From: 2012-01
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: 674279
Date Effective From: 2012-01
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: 674277
Date Effective From: 2012-01
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: 674291
W° Bound: -81.3957
E° Bound: -80.831008
N° Bound: 32.250903
S° Bound: 31.713978

Extent Group 1 / Time Frame 1

CC ID: 674281
Time Frame Type: Discrete
Start: 2009-02-21

Extent Group 1 / Time Frame 2

CC ID: 674282
Time Frame Type: Discrete
Start: 2009-02-23

Extent Group 1 / Time Frame 3

CC ID: 674283
Time Frame Type: Discrete
Start: 2009-02-24

Extent Group 1 / Time Frame 4

CC ID: 674284
Time Frame Type: Discrete
Start: 2009-03-03

Extent Group 1 / Time Frame 5

CC ID: 674285
Time Frame Type: Discrete
Start: 2009-03-04

Extent Group 1 / Time Frame 6

CC ID: 674286
Time Frame Type: Discrete
Start: 2009-03-20

Extent Group 1 / Time Frame 7

CC ID: 674287
Time Frame Type: Discrete
Start: 2009-03-21

Extent Group 1 / Time Frame 8

CC ID: 674288
Time Frame Type: Discrete
Start: 2009-03-22

Extent Group 1 / Time Frame 9

CC ID: 674289
Time Frame Type: Discrete
Start: 2009-03-23

Extent Group 1 / Time Frame 10

CC ID: 674290
Time Frame Type: Discrete
Start: 2009-06-27

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

The 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: 740978
Start Date: 2019-12-04
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=1121
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2012-01 - Present)
File Name: Customized Download
Description:

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

File Type: Zip

Distribution 2

CC ID: 740979
Start Date: 2019-12-04
End Date: Present
Download URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/1121
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2012-01 - Present)
File Name: Bulk Download
Description:

Simple download of data files.

File Type: LAZ

URLs

URL 1

CC ID: 740981
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 740982
URL: https://coast.noaa.gov
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 674301
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 674300
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: 718282
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 740980
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

Horizontal Positional Accuracy:

Lidar acquired and processed to meet 1 m (RMSE) horizontal accuracy.; Quantitative Value: 0.5 meters, Test that produced the value:

Horizontal point accuracy is a function of angular origination of the pulse;

IMU orientation; the scanner encoder and ranging function and will vary depending on the proposed point density selected for

the collection. Statistically, the error is roughly 1/3 of the illuminated foot print on the ground and is a function of the

beam divergences.

Vertical Positional Accuracy:

The vertical accuracy is based on the Sanborn independent collection of 20 ground survey points distributed throughout the project.

The fundamental vertical accuracy at 95 percent confidence level in open terrain tested 0.07 meters (0.25 ft).

1. Vertical accuracy: Less than 0.30 feet RMSEz = less than 0.60 feet vertical accuracy at 95% confidence level, tested in flat,

non-vegetated terrain only, employing NSSDA procedures in Reference B.

2. Validation that the data also satisfies FEMA requirements.

3. Vertical units (orthometric heights) are in US Survey Feet, NAVD88.

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

Based on the vertical accuracy testing conducted by Sanborn 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 Chatham County, Georgia satisfies

the criteria:

Countywide lidar dataset tested 0.15 m (0.49 ft) vertical accuracy at 95% confidence level in open terrain, based on open terrain

RMSEz (0.25 ft) x 1.9600.

Countywide lidar dataset tested 0.24 m (0.78 ft) vertical accuracy at 95% confidence level in all land cover categories combined,

based on consolidated RMSEz (0.40 ft) x 1.9600.

Completeness Report:

A visual qualitative assessment was performed in the source Lidar dataset.

Conceptual Consistency:

Data covers the tile scheme provided for the county.

Lineage

Sources

Airborne LiDAR Flight Details

CC ID: 674263
Contact Name: SANBORN MAP COMPANY
Publish Date: 2009-09-30
Extent Type: Discrete
Extent Start Date/Time: 2009-02-21
Source Contribution:

Data acquisition specifications | Type of Source Media: online

Process Steps

Process Step 1

CC ID: 674264
Description:

The ABGPS, IMU, and raw Leica ALS-50 LiDAR data are integrated into the LEICA ALS post processor software. The resultant file is

in a LAS binary file format. The LAS file version 1.1 formats 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 geodetic coordinates referenced to the NAD83 horizontal datum and GRS80 vertical datum.

Process Date/Time: 2009-01-01 00:00:00

Process Step 2

CC ID: 674265
Description:

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:

Flight Date Julian, Year, and Class. The LAS files do not include an overlap class.

The data was classified as follows:

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

Class 2 = Ground

Class 7 = noise (outliers)

Class 9 = Water

Process Date/Time: 2009-01-01 00:00:00

Process Step 3

CC ID: 674266
Description:

Conversion from Geodetic coordinates, NAD83 into State Plane coordinates (U.S. Survey Feet) NAD83 and conversion from ellipsoid

heights (meters) into orthometric heights (U.S. Survey Feet).

Process Date/Time: 2009-01-01 00:00:00

Process Step 4

CC ID: 674267
Description:

Ground points were extracted from the Lidar dataset and used in conjunction with breaklines to hydrologically enforce a DTM surface

and converted to an ESRI GRID (1m pixels) using ArcGIS.

Process Date/Time: 2009-01-01 00:00:00

Process Step 5

CC ID: 674268
Description:

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 GA State Plane coordinates and NAVD88 (orthometric) heights in feet. OCM performed the

following processing for data storage and Digital Coast provisioning purposes:

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

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

3. The data were filtered to remove outliers.

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

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

Child Items

Rubric scores updated every 15m

Rubric Score Type Title
Entity (ENT) LAS

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2009 Lidar DEM: Chatham, GA

DEM created from this point cloud.

Catalog Details

Catalog Item ID: 49725
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:21+0000
Metadata Record Last Modified By: Kirk Waters
Metadata Record Last Modified: 2019-12-04 09:19+0000
Metadata Record Published: 2018-03-13
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2019-03-14