Quantum Spatial, Inc.
20190501
Missouri 2017 LiDAR; Swath Point Cloud; Lift: 20180102A (SN8119, N916WC)
Lidar point cloud
Product: These lidar data are unclassified swath LAS 1.4 files, used to
create classified LAS 1.4 files and subsequent data. Geographic Extent: The AOI
includes 19 counties in Southern Missouri, covering approximately 11640 total square
miles. Dataset Description: The Missouri 2017 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 were developed based on a horizontal projection/datum of NAD 1983
(2011), UTM Zone 15N, meters and vertical datum of NAVD 1988 (GEOID 12B), meters.
LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 13899
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. Ground Conditions: LiDAR
was collected in winter of 2017/2018 and spring of 2018, 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. utilized a total of 231 ground control points that were used
to calibrate the LiDAR to known ground locations established throughout the project
area. An additional 380 independent accuracy checkpoints, 224 in Bare Earth and
Urban landcovers (224 NVA points), 156 in Tall Weeds categories (156 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. G16PC00016, Task Order No. 140G0218F0015; CONTRACTOR:
Quantum Spatial, Inc.
USGS-NGP Base Specification v1.2
Leica ALS80
Unlimited
0.59
2.88
0.59
2.88
2663
140
16
50.9
317.2
2.5
0.59
1064
1
0.22
1527.25
30
GEOID 12B
NAD 1983 (2011) UTM Zone 15N, meters
0.196
0.106
221
1.4
6
Withheld (ignore) points were identified in these files using the
standard LAS Withheld bit
Swath "overage" points were identified in these files using the
standard LAS overlap bit
16
0
Never processed
20180102
ground condition
None planned
-92.5894196259
-92.3728066529
38.4370501437
37.9170193116
None
Model
LAS Point Cloud
Remote Sensing
Elevation Data
Lidar
Hydrology
None
State of Missouri
Camden County
Carter County
Crawford County
Dallas County
Dent County
Gasconade County
Hickory County
Iron County
Laclede County
Madison County
Maries County
Miller County
Morgan County
Phelps County
Polk County
Pulaski County
Reynolds County
Shannon County
Texas County
No restrictions apply to these data.
All deliverable data and documentation shall be free from restrictions regarding
use and distribution. Data and documentation provided under this Task Order shall be
freely distributable by government agencies. 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 their
limitations.
Data cover the entire area specified for this project.
These raw LAS data files include 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 Non-Vegetated Vertical Accuracy specifications.
The project specifications require that only Non-Vegetated Vertical
Accuracy (NVA) be computed for raw LiDAR point cloud swath files. The required
accuracy (ACCz) is: 19.6 cm at a 95% confidence level, derived according to
NSSDA, i.e., based on RMSE of 10 cm in the "bare earth" and "urban" land cover
classes. The NVA was tested with 221 checkpoints located in bare earth and urban
(non-vegetated) areas. These checkpoints were not used in the calibration or
post processing of the LiDAR point cloud data. The checkpoints were distributed
throughout the project area and were surveyed using GPS techniques. See survey
report for additional survey methodologies. Elevations from the unclassified
LiDAR surface were measured for the x,y location of each checkpoint. Elevations
interpolated from the LiDAR surface were then compared to the elevation values
of the surveyed control points. AccuracyZ has been tested to meet 19.6 cm or
better Non-Vegetated Vertical Accuracy at 95% confidence level using RMSE(z) x
1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA);
assessed and reported using National Digital Elevation Program (NDEP)/ASRPS
Guidelines.
0.106
Tested 0.106 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 raw LiDAR point cloud swath files was calculated
against TINs derived from the final calibrated and controlled swath data
using 221 independent checkpoints located in Bare Earth and Urban land cover
classes.
Raw Data and Boresight Processing: The boresight for each lift was done
individually as the solution may change slightly from lift to lift. The
following steps describe the Raw Data Processing and Boresight process: 1)
Technicians processed the raw data to LAS format flight lines using the final
GPS/IMU solution. This LAS data set was used as source data for boresight. 2)
Technicians first used Quantum Spatial, Inc. proprietary and commercial software
to calculate initial boresight adjustment angles based on sample areas selected
in the lift. These areas cover calibration flight lines collected in the lift,
cross tie, and production flight lines. These areas are well distributed in the
lift coverage and cover multiple terrain types that are necessary for boresight
angle calculation. The technician then analyzed the results and made any
necessary additional adjustment until it was acceptable for the selected areas.
3) Once the boresight angle calculation was completed for the selected areas,
the adjusted settings were applied to all of the flight lines of the lift and
checked for consistency. The technicians utilized commercial and proprietary
software packages to analyze how well flight line overlaps matched for the
entire lift and adjusted as necessary until the results met the project
specifications. 4) Once all lifts were completed with individual boresight
adjustment, the technicians checked and corrected the vertical misalignment of
all flight lines and also the matching between data and ground truth. The
relative accuracy was less than or equal to 7 cm RMSEz within individual swaths
and less than or equal to 10 cm RMSEz or within swath overlap (between adjacent
swaths). 5) The technicians ran a final vertical accuracy check of the
boresighted flight lines against the surveyed checkpoints after the z correction
to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required
Accuracy) was met.
2018
Point
Universal Transverse Mercator
15
0.9996
-93
0
500000
0
coordinate pair
0.01
0.01
meters
NAD 1983 (2011)
Geodetic Reference System 80
6378137.0
298.257222101
NAVD 1988 (GEOID 12B)
0.01
meters
Explicit elevation coordinate included with horizontal coordinates
20190501
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