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Short Citation:
OCM Partners, 2022: 2008 South Carolina Lidar: Cherokee County, https://www.fisheries.noaa.gov/inport/item/49961.

Item Identification

Title: 2008 South Carolina Lidar: Cherokee County
Short Name: sc2008_cherokee_m510_metadata
Status: Completed
Publication Date: 2009
Abstract:

The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens,

Greenwood, Newberry, Chester, Fairfield, Lancaster, Chesterfield, Marlboro, Darlington, Dillon, Marion,

Williamsburg, Clarendon, and Orangeburg. This metadata file is for the lidar county deliverables for Cherokee County, SC.

The project area consists of approximately 10,194 square miles including a buffer of 50 feet along the edges of the

project area and an additional buffer in some areas. The project design of the lidar data acquisition was developed

to support a nominal post spacing of 1.4 meters. The Fugro EarthData, Inc. acquisition team of Fugro Horizons, Inc.

and North West Group acquired 721 flight lines in 44 lifts from January 15, 2008 through February 10, 2008. The data

was divided into 5000' by 5000' foot cells that serve as the tiling scheme. Lidar data collection was performed with a

Cessna 310 aircraft, utilizing a Leica ALS50-II MPiA sensor, collecting multiple return x, y, and z data as well as

intensity data. Lidar data was processed to achieve a bare ground surface (Classes 2 and 8). Lidar data is remotely

sensed high-resolution elevation data collected by an airborne collection platform. Using a combination of laser range

finding, GPS positioning and inertial measurement technologies, lidar instruments are able to make highly detailed

Digital Elevation Models (DEMs) of the earth's terrain, man-made structures, and vegetation.

Purpose:

The purpose of this project is to collect and deliver topographic elevation point data derived from multiple

return light detection and ranging (lidar) measurements for a 16-county area in South Carolina. The elevation data will

be used as base data for South Carolina's flood plain mapping program (as part of FEMA's Map Modernization

Program) and for additional geospatial map products in the future.

Notes:

10605

Supplemental Information:

The LiDAR Quality Assurance (QA) Report Cherokee County, South Carolina may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/510/supplemental/LiDAR_QAQC_Report_Cherokee.pdf

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
elevation
UNCONTROLLED
None Bare Earth
None Intensity
None Surface
None Terrain

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:

The information contained in the LAS point cloud data set are the following attributes; X, Y, Z to two significant digits;

Intensity as integer; Class as integer; Return number; Number of returns; Scan direction; scan angle rank; GPS time.

Entity Attribute Detail Citation:

Lidar point cloud data tiled in LAS 1.1 format; ASPRS classification scheme, class 12 - flight line overlap points,

class 9 - points in water, class 8 - model-key points, class 2 - ground points, and class 1 - all other.

Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners.

Support Roles

Data Steward

CC ID: 684984
Date Effective From: 2009
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: 684986
Date Effective From: 2009
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: 684987
Date Effective From: 2009
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: 684985
Date Effective From: 2009
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: 1138112
W° Bound: -81.874826
E° Bound: -81.366778
N° Bound: 35.184054
S° Bound: 34.828191

Extent Group 1 / Time Frame 1

CC ID: 1138111
Time Frame Type: Range
Start: 2008-01-15
End: 2008-02-10

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: 742322
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=510
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: 742323
Download URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/510/index.html
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 742325
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 742326
URL: https://coast.noaa.gov
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 685004
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 685003
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: 718562
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 742324
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Accuracy:

The following methods are used to assure lidar accuracy:

1. Use of IMU and ground control network utilizing GPS techniques

2. Use of airborne GPS in conjunction with the acquisition of lidar

3. Measurement of quality control ground survey points within the finished product.

The boresight of the lidar was processed against the ground control for Cherokee County which consisted of

9 lidar ground survey points and 1 airborne GPS (ABGPS) base station at the operation airport. The horizontal datum

for the control was the North American Datum of 1983, 2007 adjustment (NAD83/2007). The vertical datum was

the North American Vertical Datum of 1988 (NAVD88). The Geoid 2003 model was used to transform the

ellipsoidal heights to GPS derived orthometric heights. ABGPS data was collected during the acquisition mission

for each flight line. During the data acquisition the Positional Dilution of Precision (PDOP) for the ABGPS

was monitored. The control points were measured by technicians using Terrascan and Fugro EarthData

proprietary software and applied to the boresight solution for the project lines.

Horizontal Positional Accuracy:

The minimum expected horizontal accuracy was tested during the boresight process to meet or exceed the

National Standard for Spatial Data Accuracy (NSSDA). Horizontal accuracy is 1 meter RMSE or better.

Vertical Positional Accuracy:

123 high accuracy checkpoints were surveyed following FEMA Guidelines and Specifications for Flood Hazard Mapping

Partners Appendix A: Guidance for Aerial mapping and Surveying which is based on the NSSDA.

Compared with the 0.363m specification for vertical accuracy at the 95% confidence level, equivalent to 2-foot contours,

the dataset passes by all methods of accuracy assessment (tested by Dewberry):

Tested 0.129 meter Fundamental Vertical Accuracy at 95 percent confidence level in open terrain using

RMSEz x 1.9600 (FEMA/NSSDA and NDEP/ASPRS methodologies);

Tested 0.142 meter Consolidated Vertical Accuracy at 95th percentile in all land cover categories combined (NDEP/ASPRS methodology);

Tested 0.174 meter Supplemental Vertical Accuracy at 95th percentile in Vegetated terrain (NDEP/ASPRS methodology);

Tested 0.097 meter Supplemental Vertical Accuracy at 95th percentile in Urban terrain (NDEP/ASPRS methodology).

Completeness Measure:

Cloud Cover: 0

Completeness Report:

The bare earth surface will contain voids where insufficient energy was reflected from the surface to generate a valid

return from the terrain. Voids in the bare earth surface tend to occur in heavily vegetated areas, water bodies, and

beneath buildings, motor vehicles, bridges etc. Fresh or wet asphalt, wet sand and certain types of vegetation can

also cause voids or anomalous elevations.

Conceptual Consistency:

Compliance with the accuracy standard was ensured by the collection of GPS ground control during the acquisition

of aerial lidar and the establishment of a GPS base station operation airport. The following checks were performed.

1. The ground control and airborne GPS data stream were validated through a fully analytical boresight adjustment.

2. The Lidar elevation data were checked against the project control.

3. Lidar elevation data was validated through an inspection of edge matching and visual inspection for quality

(artifact removal).

Lineage

Sources

Aerial Acquisition of Lidar Data for 16 counties in the State of South Carolina

CC ID: 1138102
Publish Date: 2008-02-15
Extent Type: Range
Extent Start Date/Time: 2008-01-15
Extent End Date/Time: 2008-02-10
Source Contribution:

The Fugro EarthData, Inc. acquisition team of Fugro Horizons, Inc. and North West Group collected ALS50-II

derived lidar over 16 counties in the State of South Carolina with a 1.4m, nominal post spacing using a

Cessna 310 aircraft. The collection for the entire project area was accomplished from January 15, 2008 through

February 10, 2008 (Flight dates were January 15, 16, 18, 20, 21, 25, 27, 28, 29, 30, 31 and February 2, 3, 4, 7, 8, 10).

The collection was performed using a Leica ALS50-II MPiA lidar system, serial numbers ALS039 and ALS064,

including an inertial measuring unit (IMU) and a dual frequency GPS receiver. This project required 44 lifts of

flight lines to be collected. The lines were flown at an average of 6,000 feet above mean terrain using a

maximum pulse rate frequency of 112,000 pulses per second. The planned maximum baseline length was 50 miles.

| Type of Source Media: external hard drive

Cherokee County, SC - Digital Orthophotography

CC ID: 1138103
Extent Type: Discrete
Extent Start Date/Time: 2007-11-05
Source Contribution:

The State of South Carolina, Department of Natural Resources provided digital orthophotography covering the

project area in support of this project.

| Type of Source Media: external hard drive

South Carolina Lidar, Quality Control Surveys, 16 Counties

CC ID: 1138104
Publish Date: 2008-01-31
Extent Type: Discrete
Extent Start Date/Time: 2008-01-21
Source Contribution:

ESP under contract to Fugro EarthData, Inc. successfully established ground control for Cherokee County, SC. A

total of 9 ground control points in Cherokee County, SC were acquired. GPS was used to establish the control

network. The horizontal datum was the North American Datum of 1983, 2007 adjustment (NAD83/2007). The

vertical datum was the North American Vertical Datum of 1988 (NAVD88).

| Type of Source Media: electronic mail system

Process Steps

Process Step 1

CC ID: 1138105
Description:

1. Lidar, GPS, and IMU data was processed together using lidar processing software.

2. The lidar data set for each flight line was checked for project area coverage and lidar post spacing was checked

to ensure it meets project specifications.

3. The lidar collected at the calibration area and project area were used to correct the rotational, atmospheric, and

vertical elevation differences that are inherent to lidar data.

4. Intensity rasters were generated to verify that intensity was recorded for each lidar point.

5. Lidar data was transformed to the specified project coordinate system.

6. By utilizing the ground survey data collected at the calibration site and project area, the lidar data was

vertically biased to the ground.

7. Comparisons between the biased lidar data and ground survey data within the project area were evaluated and a

final RMSE value was generated to ensure the data meets project specifications.

8. Lidar data in overlap areas of project flight lines were trimmed and data from all swaths were merged into a single

data set.

9. The data set was trimmed to the digital project boundary including an additional buffer zone of 50 feet (buffer zone

assures adequate contour generation from the DEM).

10.The resulting data set is referred to as the raw lidar data.

Process Date/Time: 2008-06-17 00:00:00

Process Step 2

CC ID: 1138106
Description:

1. The raw lidar data was processed through a minimum block mean algorithm, and points were classified as either

bare earth or non-bare earth.

2. User developed "macros" that factor mean terrain angle and height from the ground were used to determine bare

earth point classification.

3. The next phase of the surfacing process was a 2D edit procedure that ensures the accuracy of the automated

feature classification.

4. Editors used a combination of imagery, intensity of the lidar reflection, profiles, and tin-editing software to assess

points.

5. The lidar data was filtered, as necessary, using a quadric error metric to remove redundant points. This

method leaves points where there is a change in the slope of surfaces (road ditches) and eliminates points from evenly

sloped terrain (flat field) where the points do not affect the surface.

6. The algorithms for filtering data were utilized within Fugro EarthData's proprietary software and commercial software

written by TerraSolid.

7. The flight line overlap points were merged back into filtered data set for delivery product.

8. The point cloud data were delivered tiled in LAS 1.1 format; class 12 - flight line overlap points, class 9 - points

in water, class 8 - model-key points, class 2 - ground points, and class 1 - all other.

Process Date/Time: 2008-11-10 00:00:00

Process Step 3

CC ID: 1138107
Description:

Lidar intensity images were generated in TerraSolid software. The images are then brought up in Photoshop to

see if a curve is needed to modify the radiometrics and to ensure they match from group to group. Along with looking

for missing coverage and clipping to the boundary, the following steps are run in Photoshop:

1. Flip 0 values to 1

2. Change 3-band images to 1 band

3. Restore GeoTIFF headers. The intensity images were delivered in GeoTIFF format.

Process Date/Time: 2008-11-21 00:00:00

Process Step 4

CC ID: 1138108
Description:

Tiled lidar LAS datasets are imported into a single multipoint geodatabase featureclass. Only Ground and

Model-Keypoint are imported. An ArcGIS geodatabase terrain feature class is created using the terrain creation

dialogue provided through ArcCatalog. The multipoint featureclass is imported as mass point features in the

terrain. An overall tile boundary for the county is input as a soft clip feature for the terrain. The terrain pyramid level

resolutions and scales are automatically calculated based on the point coverage for the county.

Process Date/Time: 2008-11-23 00:00:00

Process Step 5

CC ID: 1138109
Description:

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

LiDAR intensity and elevation measurements. OCM performed the following processing on the data to make it available

within Digital Coast:

1. The data were converted from State Plane, SPCS Zone 3900 coordinates to geographic coordinates.

2. The data were converted from NAVD88 heights to ellipsoid heights using Geoid03.

3. The LAS header fields were sorted by latitude and updated.

Process Date/Time: 2009-09-01 00:00:00

Catalog Details

Catalog Item ID: 49961
GUID: gov.noaa.nmfs.inport:49961
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:23+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