2012 Georgia Department of Natural Resources (GADNR) Topographic LiDAR: Pickens, Rockdale
and Troup Counties
This kmz file shows the extent of coverage for the 2012 Georgia DNR Pickens, Rockdale,
Troup Counties lidar data set.
NOAA Contract: EA133C11CQ0009 NOAA Task Order Number: T0013 The PSFY12 GADNR Elevation
Data Task Order involves: collecting and delivering topographic elevation point data
derived from multiple return light detection and ranging (LiDAR) measurements for
portions of 3 counties in Georgia. The Statement of Work (SOW) was developed by the
National Oceanic and Atmospheric Administration's (NOAA) Coastal Services Center (referred
to as the Center) in partnership with the Georgia Department of Natural Resources
(GADNR) Environmental Protection Division (EPD). The counties included Pickens, Rockdale
and Troup. The purpose of the data is for use in coastal management decision making,
including applications such as flood plain mapping and water rights management. LiDAR
was collected at 1.0 points per square meter (1.0m GSD) for the portions of Pickens,
Rockdale and Troup Counties. This area was flown during snow free and leaf-off conditions.
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
Documentation links not available.
- Georgia Department of Natural Resources (GADNR)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||Lifts are planned to meet project specifications and are flown under cloud-free conditions
in order to collect LIDAR points at an average of 1.0 meter point spacing. This allows
the user to create Intensity Images, Break Lines, Hydro Flattened DEMs and fully Classified
LiDAR LAS files.
||2012-02-25 to 2012-04-09
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Remote Sensing
- Pickens County
- Rockdale County
- Troup County
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
| Processing Steps
- Applanix software was used in the post processing of the airborne GPS and inertial
data that is critical to the positioning and orientation of the sensor during all
flights. POSPac MMS provides the smoothed best estimate of trajectory (SBET) that
is necessary for Optech's post processor to develop the point cloud from the LiDAR
missions. The point cloud is the mathematical three dimensional collection of all
returns from all laser pulses as determined from the aerial mission. At this point
this data is ready for analysis, classification, and filtering to generate a bare
earth surface model in which the above ground features are removed from the data set.
The point cloud was manipulated within the Optech or Leica software; GeoCue, TerraScan,
and TerraModeler software was used for the automated data classification, manual cleanup,
and bare earth generation from this data. Project specific macros were used to classify
the ground and to remove the side overlap between parallel flight lines. All data
was manually reviewed and any remaining artifacts removed using functionality provided
by TerraScan and TerraModeler. Class 2 LIDAR was used to create a bare earth surface
model. The surface model was then used to heads-up digitize 2D breaklines of inland
streams and rivers. Inland Ponds and Lakes of 2 acres or greater were also collected.
Elevation values were assigned to all Inland Ponds and Lakes using TerraModeler functionality.
Elevation values were assigned to all Inland Streams and Rivers using Photo Science
proprietary software. All Class 2 LIDAR data falling inside of the collected breaklines
were then classified to Class 9 and Class 2 LIDAR data falling within a proximity
of three feet will be classified to Class 10 using TerraScan macro functionality.
The breakline files were translated to ESRI Shapefile format using ESRI conversion
tools. Data was then run through additional macros to ensure deliverable classification
levels matching LAS ASPRS Classification structure. GeoCue functionality was used
to ensure correct LAS Version. In house software was used as a final QA/QC check to
provide LAS Analysis of the delivered tiles. Tiles were run through automated scripting
within ArcMap and were combined with the Hydro Flattened Breaklines to create the
4' DEM. Final DEM tiles were clipped to the tile boundary in order to provide a seamless
dataset. A manual QA review of the tiles was completed in ArcMap and Global Mapper
to ensure full coverage with no gaps or slivers within the project area.
- The NOAA Coastal Services Center (CSC) received topographic files in LAS format. The
files contained lidar elevation and intensity measurements. The data were received
in Georgia State Plane West 1002 (NAD83) coordinates and were vertically referenced
to NAVD88 using the Geoid09 model. The vertical units of the data were feet. CSC performed
the following processing for data storage and Digital Coast provisioning purposes:
1. The topographic las files were converted from orthometric (NAVD88) heights to ellipsoidal
heights using Geoid09. 2. The topographic las files' vertical units were converted
from survey feet to meters. 3. The topographic las files were converted from a Projected
Coordinate System (GA SPW 1002) to a Geographic Coordinate system (GCS). 4. The topographic
las files' horizontal units were converted from survey feet to decimal degrees. 5.
The data were converted to LAZ format.
- The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp
transfer from the NOAA Coastal Services Center. The data are currently
being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/.
The data can be used to re-populate the system. The data are archived in LAS or LAZ
The LAS format is an industry standard for LiDAR data developed by the American Society
of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless compressed version
LAS developed by Martin Isenburg (http://www.laszip.org/). The data are exclusively
in geographic coordinates (either NAD83 or ITRF94). The data are referenced vertically
the ellipsoid (either GRS80 or ITRF94), allowing for the ability to apply the most
up to date geoid model when transforming to orthometric heights.
Metadata Last Modified: 2013-01-22
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