Data Management Plan

Between January and March 2010, lidar data was collected in southeast/coastal Georgia under a multi-agency partnership between the Coastal Georgia

Regional Development Center, USGS, FEMA, NOAA and local county governments. Data acquisition is for the full extent of coastal Georgia,

approximately 50 miles inland, excluding counties with existing high-resolution lidar derived elevation data. The data capture area consists

of an area of approximately 5703 square miles. This project is within the Atlantic Coastal Priority Area as defined by the National Geospatial

Program (NGP) and supports homeland security requirements of the National Geospatial-Intelligence Agency (NGA). This project also supports

the National Spatial Data Infrastructure (NSDI) and will advance USGS efforts related to The National Map and the National Elevation Dataset.

The data were delivered in LAS format version 1.2 in 5000 x 5000 foot tiles. The data are classified according to ASPRS LAS 1.2 classification

scheme:

Class 1 - Unclassified

Class 2 - Bare Earth

Class 7 - Low Point (Noise)

Class 9 - Water

Class 10 - Land below sea level

Class 12 - Overlap

Process Steps:

• 2010-01-01 00:00:00 - 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. The National Elevation Dataset (1/3 arc-second) was used as a supplement to calculate streams with a contributing drainage area of greater than 1 square mile. Inland Ponds, Lakes, and Mudflats of 0.5 acres or greater were also collected along with the Coastal Shoreline. Elevation values were assigned to all Inland Ponds, Lakes, and Shorelines using TerraModeler functionality. Elevation values were assigned to all Inland streams, rivers, and mudflats using Photo Science proprietary software. All Class 2 LIDAR data inside of the collected breaklines were then classified to Class 9 using TerraScan macro functionality. The breakline files were then 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 then 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. Buffered LAS files were created in GeoCue to provide overedge to the DEM creation. These tiles were then 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 to ensure full coverage with no gaps or slivers within the project area.
• 2011-04-20 00:00:00 - 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 State Plane projection (NAD83, Georgia East), and vertically referenced to NAVD88 using the Geoid 09 model. Both horizontal and vertical units were in feet. OCM performed the following processing to the data to make it available within the Digital Coast: 1. The data were converted from Georgia State Plane coordinates to geographic (NAD83) coordinates. 2. The data were converted from orthometric (NAVD88) heights to ellipsoidal heights (GRS80) using Geoid 09. 3. The LAS data were sorted by latitude and the headers were updated.

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer;