Quantum Spatial, Inc.
20171215
Arkansas 2016 QL2 LiDAR; QC Checkpoints
Vector digital data
Product: QC checkpoints collected for independent accuracy testing of the Arkansas 2016 data and delivered in Esri shapefile format.
Geographic Extent: Twenty counties in northern Arkansas and southeastern Oklahoma, covering approximately 11,421 total square miles.
Dataset Description: Arkansas 2016 Lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data for counties in the eastern AOIs were developed based on a horizontal projection/datum of NAD83 (2011), UTM Zone 15, meters and vertical datum of NAVD88 (GEOID12B), metes. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files formatted to 13,708 individual 1,500-meter x 1,500-meter tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1,500-meter x 1,500-meter schema. Continuous breaklines were produced in Esri file geodatabase format. Building footprints were created in Esri file geodatabase format.
Ground Conditions: Lidar was collected in winter/spring of 2016/2017, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Quantum Spatial, Inc. established a total of 225 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 379 independent accuracy checkpoints, 219 in Bare Earth and Urban landcovers (219 NVA points), 160 in Forested, Brushland/Trees, and Tall Weeds/Crops categories (160 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.
To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create intensity images, breaklines and raster DEMs. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened digital elevation models (DEMs) with a 1-meter cell size. These raw lidar point cloud data were used to create classified lidar LAS files, intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.
USGS Contract No. G10PC00016 Task Order No. G17PD00010. CONTRACTOR: Quantum Spatial, Inc. SUBCONTRACTOR: Keystone Aerial Surveys, Inc., Airborne Imaging, Inc., and Atlis Geomatics, Inc. Lidar data were acquired by Keystone Aerial Surveys, Inc. Airborne Imaging, Inc., and Atlis Geomatics, Inc. All follow-on processing was completed by the prime contractor.
20161215
20170128
ground condition
None planned
-95.1684511558745
-91.19277227219826
36.5139980030912
34.0011089984167
None
Model
QC Checkpoints
None
Arkansas
Baxter County
Boone County
Carroll County
Cleburne County
Fulton County
Independence County
Izard County
Johnson County
Lawrence County
Madison County
Marion County
Newton County
Searcy County
Sharp County
Stone County
Van Buren County
Oklahoma
Adair County
Le Flore County
McCurtain County
Sequoya County
No restrictions apply to this data.
None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.
Data covers the entire area specified for this project.
All files are inspected to ensure that they conform to the specified file naming conventions, all files load in their correct geographic position, all files conform to the project specifications for file standard and content.
QC Checkpoint Creation: Please see the survey report for more information on control point location methodologies. The QC checkpoint shapefiles were generated from XYZ text files using a combination of Global Mapper and ArcMap software.
2017
Vector
Universal Transverse Mercator
15
0.9996
-93.0
0.0
500000.0
0.0
coordinate pair
0.01
0.01
meters
North American Datum of 1983 (2011)
Geodetic Reference System 80
6378137.0
298.257222101
North American Vertical Datum of 1988 (GEOID12B)
0.01
meters
Explicit elevation coordinate included with horizontal coordinates
QC Checkpoint
An accurately surveyed coordinate location for a physical feature that can be identified on the ground. Control points are used in least-squares adjustments as the basis for improving the spatial accuracy of all other points to which they are connected.
Esri GIS Dictionary http://support.esri.com/en/knowledgebase/GISDictionary/term/control%20point
FID
Internal feature number.
Esri
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
Esri
Feature geometry - Point ZM
Name
Name assigned to each QC checkpoint
LiDAR Data
Unique identifier assigned to each QC checkpoint. Point numbers assigned by surveyor
POINT_X
Easting coordinate in project coordinate system for each QC checkpoint
LiDAR Data
QC Checkpoint Easting
Easting coordinate in project coordinate system for each QC checkpoint
Values are calculated by survey manager
POINT_Y
Northing coordinate in project coordinate system for each QC checkpoint
LiDAR Data
QC Checkpoint Northing
Northing coordinate in project coordinate system for each QC checkpoint
Values are calculated by survey manager
POINT_Z
Elevation in project coordinate system for each QC checkpoint
LiDAR Data
QC Checkpoint Elevation
Elevation in project coordinate system for each QC checkpoint
Values are calculated by survey manager
QC checkpoint are used to check the vertical accuracy of the LiDAR data.
More detail about the attributes of this data set can be found in LAS 1.4 specifications and USGS LiDAR Base Specification Version 1.2.
20171215
Quantum Spatial
mailing and physical
523 Wellington Way
Lexington
KY
40503
USA
859-277-8700
859-277-8901
Monday through Friday 8:00 AM to 5:00 PM (Eastern Time)
If unable to reach the contact by telephone, please send an email. You should get a response within 24 hours.
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
None.
None.
None.
Unclassified
NONE