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Short Citation:
OCM Partners, 2022: 2010 ARC Dekalb County Georgia Lidar, https://www.fisheries.noaa.gov/inport/item/49728.

Item Identification

Title: 2010 ARC Dekalb County Georgia Lidar
Short Name: ga2010_arc_dekalbcounty_m2527_metadata
Status: Completed
Publication Date: 2012-08-13
Abstract:

This metadata record describes the DTM comprised of classified aerial lidar elevation points, photogrammetrically compiled breaklines and the derived TIN for Dekalb County, GA

Original contact information:

Contact Name: Stacy Grear

Contact Org: Dekalb County GIS Department

Title: Acting Director

Phone: 404-371-3619

Email: scgrear@dekalbcountyga.gov will change to scgrear@dekalbcountyga.gov on July 1, 2010

Purpose:

The lidar DEM data was collected for the Dekalb County, GA area. All lidar returns were classified using the default classes of Terrascan processing software for Unclassified Points (class 1), Ground points (class 2), Water points (class 9), Overlap points (class 12). The lidar ground points are supplemented with photogrammmetrically compiled breaklines from digital imagery collected during the same project time frame as the lidar. The ground class points, often refered to as "bald earth" are then used as an input to proprietary and publicly available processing software to generate a Triangulated Irregular Network (TIN) model. Classified lidar DEMs and derived TIN models are useful for a variety of applications, such as aiding in contour generation, development of digital surface models, 3D modeling, flood plane mapping, viewshed analysis and the production of orthophotos.

Notes:

10373

Supplemental Information:

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

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2527/supplemental/ga2010_dekalbcounty.KMZ

A Lidar Report from the vendor for this data set may be viewed here:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2527/supplemental/ga2010_dekalbcounty_QC_Report.pdf

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation
UNCONTROLLED
None mapping
None TIN
None Triangulated Irregular Network

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: Unknown
Data Presentation Form: Point and vector digital data
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 Kucera International, ARC, USGS, NOAA, the Office for Coastal Management or its partners.

Data Set Credit: Please credit the Deklab County GIS Department Puget with support from the Atlanta Regional Commission with this data.

Support Roles

Data Steward

CC ID: 674411
Date Effective From: 2012-08-13
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: 674413
Date Effective From: 2012-08-13
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: 674414
Date Effective From: 2012-08-13
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: 674412
Date Effective From: 2012-08-13
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: 1134282
W° Bound: -84.35091417
E° Bound: -84.02334971
N° Bound: 33.97061816
S° Bound: 33.61447836

Extent Group 1 / Time Frame 1

CC ID: 1134280
Time Frame Type: Discrete
Start: 2010-01-02

Extent Group 1 / Time Frame 2

CC ID: 1134281
Time Frame Type: Discrete
Start: 2010-01-03

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. These data

depict the heights at the time of the survey and are only accurate for that time.

Distribution Information

Distribution 1

CC ID: 740995
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=2527
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: 740996
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2527/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 740998
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 740999
URL: https://coast.noaa.gov
URL Type:
Online Resource

URL 3

CC ID: 741000
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/2527/supplemental/ga2010_dekalbcounty.KMZ
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic shows the lidar coverage for the 2010 Dekalb County Lidar Survey in Georgia.

Activity Log

Activity Log 1

CC ID: 674431
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 674430
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: 718285
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 740997
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Accuracy:

Attribute accuracy is tested in the LiDAR processing stage. After classification of the LiDAR data, the 'bald earth' point class is compared to ground control collected within the project area.

Horizontal Positional Accuracy:

Horizontal positional accuracy for LiDAR is dependent upon the quality of the GPS/INS solution, sensor calibration and ground conditions at the time of data capture. The standard system results for horizontal accuracy are less than 1 meter.; Quantitative Value: 1 meters, Test that produced the value: This value is computed by comparing ground control to an intensity based image derived from the classified LiDAR data and represents the RMSE of residuals on controls within the project area.

Vertical Positional Accuracy:

Vertical positional accuracy for LiDAR is dependent upon the quality of the GPS/INS solution, sensor calibration and ground conditions at the time of data capture. The vertical accuracy for this project was tested with a resultant RMSE of 0.057 meter (0.188 feet).; Quantitative Value: 0.057 meters, Test that produced the value: This value is computed by comparing ground control elevation to the classified LiDAR ground surface and represents the RMSE of residuals on controls within the project area. Units = meters.

Completeness Report:

LiDAR data is collected for the project area. Post processing of the simultaneously acquired GPS/INS is performed and applied to the laser returns to output a point cloud in the specified project coordinate system and datums. The point cloud data is then subjected to automated classification routines to assign all points in the point cloud to ground, water, overlap and unclassified point classes. Anomalous laser returns that occur infrequently are removed entirely from the data set. The ground class points are then compared to surveyed ground control to develop an accuracy measure of the laser terrain data.

Conceptual Consistency:

LiDAR data is collected within the project area, processed and verified against control.

Lineage

Sources

Aerial Digital Imagery

CC ID: 1134264
Extent Type: Discrete
Extent Start Date/Time: 2010-02-18
Source Contribution:

New digital aerial imagery and GPS/IMU data was recorded for the defined project area. | Source Geospatial Form: Remote sensing image | Type of Source Media: disc

Ground control

CC ID: 1134265
Publish Date: 2010-01-01
Extent Type: Discrete
Extent Start Date/Time: 2010
Source Contribution:

Targeted ground control is used to create a digital control file and control report as well as QC check of LiDAR accuracy. Predefined points (NGS when available) within the project area are targeted. | Source Geospatial Form: tabular digital data | Type of Source Media: disc

LiDAR Data

CC ID: 1134266
Extent Type: Discrete
Extent Start Date/Time: 2010-01-02
Source Contribution:

Aerial LiDAR and GPS/IMU data was recorded for the defined project area. | Source Geospatial Form: Remote sensing image | Type of Source Media: disc

Triangulated Irregular Network

CC ID: 1134267
Publish Date: 2010-01-01
Extent Type: Discrete
Extent Start Date/Time: 2010
Source Contribution:

Using the lidar elevation points and compiled breaklines as inputs, a Triangulated Irregular Network (TIN) is generated using ESRI ArcGIS software. | Source Geospatial Form: Vector digital data | Type of Source Media: disc

Process Steps

Process Step 1

CC ID: 1134268
Description:

At selected locations throughout the site, accurate GPS coordinates and elevations are surveyed and the points are marked with targets.

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

Process Step 2

CC ID: 1134271
Description:

New LiDAR data is captured for the project area using a Leica ALS60 LiDAR instrument in conjunction with a POSAV Applanix GPS/INS system mounted within a Piper Navajo twin engine airplane.

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

Process Step 3

CC ID: 1134272
Description:

New aerial digital imagery with airborne GPS/IMU data is acquired for the project area.

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

Process Step 4

CC ID: 1134273
Description:

The airborne GPS data is processed in Terratec TerraPos software and then combined with the IMU data in Applanix PosPAC software to determine the LiDAR sensor's angle and orientation in the terrain (project) coordinate system and datums during the survey. The same GPS/IMU processing is performed for the digital imagery to define the orientation parameters of the images to be used in stereo compilation of terrain breaklines.

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

Process Step 5

CC ID: 1134274
Description:

LiDAR data is processed using the GPS/INS solution. Data is classified to produce:

Class 1: unclassified points

Class 2: ground points

Class 9: water points

Class 12: overlap points

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

Process Step 6

CC ID: 1134275
Description:

The ground class of the processed lidar data is then compared to the ground control and elevation differences between the lidar surface and surveyed elevation are recorded in tabular form. Vertical accuracy statistices are then developed to produce vertical RMSE and overall accuracy estimates and reports.

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

Process Step 7

CC ID: 1134276
Description:

Photogrammetrically compiled breaklines are compiled to supplement the lidar ground points.

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

Process Step 8

CC ID: 1134277
Description:

Water polygons are buffered to remove any lidar points within the polygon to flatten these surfaces.

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

Process Step 9

CC ID: 1134278
Description:

Breaklines are buffered to remove lidar surface points on or near the breakline.

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

Process Step 10

CC ID: 1134269
Description:

The Traingulated Irregular Network is generate with ESRI ArcGIS software.

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

Process Step 11

CC ID: 1134270
Description:

The NOAA Office for Coastal Management (OCM) received topographic files in LAS format. The files contained lidar

elevation and intensity measurements. The data were received in projected Georgia State Plane West Zone 1002 coordinates

and were vertically referenced to NAVD88. The vertical units of the data were feet. OCM performed the following processing

for data storage and Digital Coast provisioning purposes:

1. The LAS files were processed through a lastools program known as LASGround, where an algorithm further processes any unclassified points to the ground class, ignoring pre-exisint ground points.

2. All files were then horizontally shifted from the projected GA_W (1002) state place coordinates (in feet) to geographic NAD83 coordinates (decimal degrees)

3. All files were then vertically shifted from from orthometric NAVD88 heights (feet) to ellipsoidal NAD83 (meters) using GEOID09 (assumed based on processing date)

Process Date/Time: 2013-08-09 00:00:00

Catalog Details

Catalog Item ID: 49728
GUID: gov.noaa.nmfs.inport:49728
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