Slide Menu
Search Help Show/Hide Menu
Short Citation:
OCM Partners, 2024: 2017 GA DNR Lidar: Middle Chattahoochee - Walter F Watershed, https://www.fisheries.noaa.gov/inport/item/57398.

Item Identification

Title: 2017 GA DNR Lidar: Middle Chattahoochee - Walter F Watershed
Short Name: ga2017_chattahoochee_m8839
Status: Completed
Creation Date: 2019-09-11
Abstract:

Product: These are LAZ compressed LAS LiDAR data as part of the required deliverables for the Lidar project. These lidar data are processed Classified LAS 1.4 files; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 2 meter (6 feet) hydro-flattened Raster DEM data product consists of processed topographic elevation point data derived from multiple return light detection and ranging (lidar) measurements. The lidar data was planned and acquired at 2 points per square meter for the project boundary identified in the shapefile provided NOAA on January 6th, 2017. The developed lidar derivatives are hydro-flattened DEMs.

Geographic Extent: The Atlantic Group, LLC (Atlantic) has successfully completed lidar acquisition for the Georgia 9 County Lidar area of interest (AOI). Lidar for this AOI was acquired in sixteen (16) flight missions completed between November 25th, 2017 and January 24th, 2018. The project area encompasses 1,550,933 acres, 6,276 square kilometers or 2,440 square miles in Georgia covering the Middle Chattahoochee Walter‐F Watershed including Taylor, Chattahoochee, Stewart, Webster, Quitman, Randolph, and Clay Counties; Upper Flint Watershed including portions of Pike, Lamer and Upson Counties; and a portion of Lee County in the Kinchafoonee‐Muckalee Watershed.

In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data, and the hydro breaklines are also available. These data are available for download at the links provided in the URL section of this metadata record.

Purpose:

The data produced is intended to support local hydrologists and watershed managers in their decision-making processes.

Supplemental Information:

File Type: LAZ (compressed LAS)

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Lidar Specification v1.2",

"ldrsens" : " Leica ALS70-HP",

"ldrmaxnr" : "6",

"ldrnps" : "0.5",

"ldrdens" : "2.2",

"ldranps" : "0.4116",

"ldradens" : "5.9",

"ldrfltht" : "1957",

"ldrfltsp" : "120",

"ldrscana" : "45",

"ldrscanr" : "34.8",

"ldrpulsr" : "263",

"ldrpulsd" : "4",

"ldrpulsw" : "0.43",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1,673",

"ldrswato" : "20",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0.119",

"rawnvan" : "29",

"clsnva" : "0.119",

"clsnvan" : "29",

"clsvva" : "0.216",

"clsvvan" : "20"

},

"lasinfo" : {

"lasver" : "1.2",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS Withheld bit.",

"lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit.",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare Earth Ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored Ground"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

}

}}

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
ISO 19115 Topic Category
elevation
UNCONTROLLED
ISO 19115 Topic Category Digital Terrain Model
ISO 19115 Topic Category LAS
ISO 19115 Topic Category LiDAR
None beach
None DEM
None digital elevation model
None erosion
None laser
None lidar
None National Oceanic and Atmospheric Administration (NOAA)
None NOAA
None Topography

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > GEORGIA
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > LAND SURFACE
UNCONTROLLED
None Chattahoochee
None Clay
None Kinchafoonee-Muckalee Watershed
None Lamar
None Lee
None Middle Chattahoochee Walter-F Watershed
None Pike
None Quitman
None Randolph
None Stewart
None Taylor
None Upper Flint Watershed
None Upson
None Webster

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords
LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords
Airplane > Airplane

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: As Needed
Data Presentation Form: Model (digital)
Distribution Liability:

The data represented is the result of data collection and processing per contract specifications and indicates the general existing conditions at the time of 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 GA DNR, NOAA, the Office for Coastal Management or its partners.

Data Set Credit: The Atlantic Group, LLC, GA DNR

Support Roles

Data Steward

CC ID: 871773
Date Effective From: 2019
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: 871774
Date Effective From: 2019
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: 871775
Date Effective From: 2019
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: 871776
Date Effective From: 2019
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: 871779
W° Bound: -85.142949
E° Bound: -84.000872
N° Bound: 33.190413
S° Bound: 31.484983

Extent Group 1 / Time Frame 1

CC ID: 871778
Time Frame Type: Range
Start: 2017-11-25
End: 2018-01-24

Spatial Information

Spatial Representation

Representations Used

Grid: No
Vector: Yes
Text / Table: No
TIN: No
Stereo Model: No
Video: No

Vector Representation 1

CC ID: 871768
Point Object Present?: Yes
Point Object Count: 29219699679

Reference Systems

Reference System 1

CC ID: 871820

Coordinate Reference System

CRS Type: Geographic 3D
EPSG Code: EPSG:6319
EPSG Name: NAD83(2011)
See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for bulk and custom downloads.

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: 871780
Start Date: 2019-09-11
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8839
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2019 - Present)
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc. A new metadata will be produced to reflect your request using this record as a base.

File Type (Deprecated): Zip
Compression: Zip

Distribution 2

CC ID: 871781
Start Date: 2019-09-11
End Date: Present
Download URL: https://coast.noaa.gov/htdata/lidar3_z/geoid12b/data/8839
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2019 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in LAZ format, geographic coordinates, orthometric heights. Note that the vertical datum (hence elevations) of the files here are different than described in this document.

File Type (Deprecated): LAZ
Distribution Format: LAS/LAZ - LASer
Compression: Zip

URLs

URL 1

CC ID: 871770
URL: https://coast.noaa.gov/dataviewer/
Name: NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV)
URL Type:
Online Resource
File Resource Format: HTML
Description:

The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer.

URL 2

CC ID: 871771
URL: https://coast.noaa.gov/htdata/lidar3_z/geoid12b/data/8839/supplemental/ga2017_chattahoochee_m8839.kmz
Name: Browse graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 3

CC ID: 871772
URL: https://coast.noaa.gov/htdata/lidar3_z/geoid12b/data/8839/supplemental/17019_Aerial_Lidar_Report.pdf
Name: Dataset report
URL Type:
Online Resource
File Resource Format: PDF
Description:

Link to data set report.

URL 4

CC ID: 871821
URL: https://coast.noaa.gov/htdata/lidar3_z/geoid12b/data/8839/breaklines/
URL Type:
Online Resource
Description:

Link to the hydro breaklines.

URL 5

CC ID: 871823
URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8840
URL Type:
Online Resource
Description:

Link to custom download, from the Data Access Viewer (DAV), the raster Digital Elevation Model (DEM) data that were created from this lidar data set.

URL 6

CC ID: 871828
URL: https://coast.noaa.gov/
Name: NOAA's Office for Coastal Management (OCM) website
URL Type:
Online Resource
File Resource Format: HTML
Description:

Information on the NOAA Office for Coastal Management (OCM)

Data Quality

Horizontal Positional Accuracy:

As described in Section 7.5 of the ASPRS Positional Accuracy Standards for Digital Geospatial Data the horizontal errors in lidar data are largely a function of GNSS positional error, INS angular error, and flying altitude. Therefore, lidar data collected with GNSS error of 8cm and the IMU error of 0.00427 degrees at an altitude of 1,957m; the expected radial horizontal positional error will be RMSEr = 43cm.

Vertical Positional Accuracy:

Atlantic established a total of fifty-two (52) check points for this project (29 NVA + 23 VVA). Point cloud data accuracy was tested against a Triangulated Irregular Network (TIN) constructed from lidar points in clear and open areas. A clear and open area can be characterized with respect to topographic and ground cover variation such that a minimum of 5 times the NPS exists with less than 1/3 of the RMSEZ deviation from a low-slope plane. Slopes that exceed 10 percent were avoided. Each land cover type representing 10 percent or more of the total project area were tested and reported with a VVA. In land cover categories other than dense urban areas, the tested points did not have obstructions 45 degrees above the horizon to ensure a sufficient TIN surface. The VVA value is provided as a target. It is understood that in areas of dense vegetation, swamps, or extremely difficult terrain, this value may be exceeded. The NVA value is a requirement that must be met, regardless of any allowed “busts” in the VVA(s) for individual land cover types within the project. Checkpoints for each assessment (NVA and VVA) are required to be well-distributed throughout the land cover type, for the entire project area.

Below are the vertical accuracy reporting requirements for this project: Vertical Accuracy Reporting Requirements in Feet:

RMSEZ ≤ 0.328ft (Non-Vegetated Swath, DEM)

NVA ≤ 0.643ft 95% Confidence Level (Swath, DEM)

VVA ≤ 0.965ft 95th Percentile (DEM)

The NVA of the Point Cloud was calculated using 29 independent checkpoints located in the Bare Earth and Urban land cover categories. Tested 0.061 meters NVA at a 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA).

The NVA of the Bare Earth was calculated using 67 independent checkpoints located in the Bare Earth and Urban land cover categories.

Tested 0.143 meters VVA was calculated using 53 checkpoints located in the Brushlands and Low Trees and Tall Weeds and Crops land cover categories at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for Lidar Data. Tested against the DEM.

Tested 0.060 meters NVA at a 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The NVA of the DEM was calculated using 67 independent checkpoints located in the Bare Earth and Urban land cover categories.

Completeness Report:

Area of interest covers approximately 2,440 square miles around project area. The raw LAS data files included all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes NVA specifications. Void areas (i.e., areas outside the project boundary but within the tiling scheme) are coded using a unique NODATA value. This value is identified in the appropriate location within the file header.

Conceptual Consistency:

All lidar data and lidar derived data covers the entire 2,440 square mile area of interest. All lidar point cloud tiles show no edge artifacts or mismatches from tile to tile. Void areas (i.e. areas outside the project boundary but within the tiling scheme) are coded using a unique NODATA value. This value is identified in the appropriate location within the file header. Data cover the entire area specified for this project.

Data Management

Have Resources for Management of these Data Been Identified?: Yes
Approximate Percentage of Budget for these Data Devoted to Data Management: Unknown
Do these Data Comply with the Data Access Directive?: Yes
Actual or Planned Long-Term Data Archive Location: NCEI-CO
How Will the Data Be Protected from Accidental or Malicious Modification or Deletion Prior to Receipt by the Archive?:

Data is backed up to tape and to cloud storage.

Lineage

Process Steps

Process Step 1

CC ID: 871763
Description:

Survey Data Acqisition:

Project Introduction: Platinum Geomatics, LLC entered into contract with the Atlantic Group on March 1st, 2017 to perform geodetic control surveying for the calibration and quality control of 9 counties of LiDAR in South Georgia. This is a report of the methodology used and calculated accuracy of the survey performed by Platinum Geomatics, LLC.

Procedures Used: The Trimble Virtual Reference System (VRS) was employed to obtain real-time GNSS corrections for most of the points. When real-time corrections could not be obtained, due to either poor cellular connection or aerial obstructions affecting the geometric dilution of precision (GDOP), a static GNSS session was run and receiver independent exchange format (RINEX) files of the navigated position were downloaded from the VRS. Static GNSS baselines were post-processed using Trimble Business Center (TBC) software. Real-time VRS observations consisted of a minimum of 180 1-second epochs and point tolerances were set to record within 0.049’ horizontal and 0.066’ vertical accuracies.

Equipment Used: Trimble R-7, R-8, and R-10 dual frequency GNSS receivers were used.

Project Datum: Individual point coordinates were reported to NAD83 (2011) Georgia West zone. Coordinates and elevations were reported in US Survey Feet. Reported Elevations are relative to NAVD88 as derived from Geoid 12B.

Point Description Quantity Non-vegetated LiDAR Quality Control 50, Vegetated LiDAR Quality Control 37, and LiDAR Calibration 26

Process Date/Time: 2017-10-27 00:00:00

Process Step 2

CC ID: 871764
Description:

Flight Acquisition: Atlantic acquired one hundred eighty-one (181) passes of the AOI as a series of perpendicular and/or adjacent flight-lines. Differential GNSS unit in aircraft recorded sample positions at 2 Hz or more frequency. Lidar data was only acquired when a minimum of 6 satellites were in view. Atlantic lidar sensors are calibrated at a designated site located at the Fayetteville Municipal Airport (FYM) in Fayetteville, TN and are periodically checked and adjusted to minimize corrections at project sites. Atlantic operated a Cessna 210TL (N732JE) and Partenavia P68 (N775MW) outfitted with a Leica ALS70-HP lidar system during the collection of the project area. Data acquisition was completed between 24th November 2017 and 24th January 2018.

Process Date/Time: 2017-11-25 00:00:00

Process Step 3

CC ID: 871765
Description:

Lidar Pre-processing: Atlantic used a combination of Waypoint and Leica software products to extract the lidar swath data from the raw flight records. Waypoint Inertial Explorer is used to extract the raw IPAS ABGPS/IMU data, which is further processed in combination with controlled base stations to provide the final Smoothed Best Estimate Trajectory (SBET) for each mission. The SBET’s are combined with the raw laser scan files to export the (*.las) formatted swath point clouds.

Process Date/Time: 2019-07-02 00:00:00

Process Step 4

CC ID: 871766
Description:

LiDAR ranging data were initially calibrated using previous best parameters for this instrument and aircraft. Using a combination of GeoCue, and TerraSolid’s TerraScan and TerraMatch the overlapping swath point clouds are corrected for any orientation or linear deviations to obtain the best fit swath-to-swath calibration. Relative calibration was evaluated using advanced plane-matching analysis and parameter corrections derived. This process was repeated interactively until residual errors between overlapping swaths, across all project missions, was reduced to 2 cm or less. A final analysis of the calibrated LiDAR is preformed using a TerraMatch Tie Line report for an overall statistical model of the project area.

Upon completion of the data calibration, Atlantic runs a complete set of Delta-Z (dZ) ortho images. A user-defined color ramp is applied depicting the offsets between overlapping swaths based on project specifications. The dZ orthos provide an opportunity to review the data calibration in a qualitative manner. Atlantic assigns green to all offset values that fall below the required interswath accuracy RMSDz requirement of the project. A yellow color is assigned for offsets that fall between the RMSDz value and 1.5x of that value. Finally, red values are assigned to all values that fall beyond 1.5x of the RMSDz requirements of the project.

The calibrated point cloud data from the laser sensor was merged to produce processed (*.las) file(s) including but not limited to 3D position, intensity, and time-stamp. A filtering methodology was utilized to produce a multi-return surface elevation model dataset with bare-earth conditions. GeoCue, TerraScan, and TerraModel software was used for the initial batch processing and manual editing of the (*.las) point clouds. Atlantic utilized collected breakline data to perform classification for classes’ 9-Water and 10-Ignored Ground in LP360.

Process Date/Time: 2019-07-02 00:00:00

Process Step 5

CC ID: 871822
Description:

The NOAA Office for Coastal Management (OCM) received a total of 3052 laz files (in four blocks) from Tetra Tech. The lidar data had elevation and intensity measurements. The data were in State Plane Georgia West (NAD83 2011) coordinates (US Survey Feet) and NAVD88 (Geoid12B) elevations in meters. The data were classified as: 1-Unclassified, 2-Ground, 7-Low Noise, 9-Water, 10-Ignored Ground due to breakline proximity, 17-Bridge Decks, 18-High Noise . OCM processed all classifications of points to the Digital Coast Data Access Viewer (DAV). Classes available on the DAV are: 1, 2, 7, 9, 10, 17, 18.

OCM performed the following processing on the data for Digital Coast storage and provisioning purposes:

1. An internal OCM script was run to check the number of points by classification and by flight ID and the gps and intensity ranges.

2. Internal OCM scripts were run on the laz files to convert from orthometric (NAVD88) elevations to ellipsoid elevations using the Geoid 12B model, to convert from State Plane Georgia West (NAD83 2011) coordinates in US survey feet to geographic coordinates, to assign the geokeys, to sort the data by gps time, and zip the data to database and to http.

Process Date/Time: 2019-09-10 00:00:00
Process Contact: Office for Coastal Management (OCM)

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2017 GA DNR Lidar DEM: Middle Chattahoochee - Walter F Watershed

Catalog Details

Catalog Item ID: 57398
GUID: gov.noaa.nmfs.inport:57398
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2019-09-11 08:54+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2023-10-17 16:12+0000
Metadata Record Published: 2019-09-11
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2019-09-11
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2020-09-11