Quantum Spatial, Inc.
20200313
Rogue River Siskiyou
vector data
Product: 3d Water's Edge Breaklines. Breakline data was used to hydroflatten the DEMs created for the Rogue River Siskiyou lidar project. Breaklines are reviewed against lidar intensity imagery and the National Hydrographic Dataset (NHD) to verify completeness of capture.
Geographic Extent: This dataset and derived products encompass an area covering approximately 569 square miles within Siskiyou and Del Norte Counties in California as well as Josephine and Jackson Counties in Oregon.
Dataset Description: The Rogue River Siskiyou lidar project called for the planning, acquisition, and processing of lidar data collected at an aggregate nominal pulse spacing (ANPS) of 0.35 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base lidar Specification, Version 1.3. The data was developed based on the NAD83(2011) horizontal datum and NAVD88 (GEOID12B) vertical datum. Data was projected in UTM Zone 10N. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 1,652 individual 1,000 m x 1,000 m tiles. Derived products include: tiled Intensity Imagery, tiled DZ orthos, tiled hydroflattend bare earth DEMs, and 3D waters edge breaklines.
Ground Conditions: Lidar was collected in fall 2019, while the presence of snow on the ground was at a minimum 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, QSI established a total of 65 ground control points distributed throughout the Rogue River Siskiyou, Oregon project area. Lidar data was calibrated to these known ground locations. An additional 70 independent accuracy checkpoints, 43 in Bare Earth and Urban landcovers (NVA points) and 27 in Shrub, Tall Grass, and Forest categories (VVA points) were used to assess the vertical accuracy of the project data. These checkpoints were not used to calibrate or post process the data.
The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the 3DEP initiative. The raw lidar point cloud data were used to create classified lidar las files, hydroflattened DEMs, intensity images, dz orthos, and 3D hydro breaklines.
CONTRACTOR: Quantum Spatial, Inc.
Ground Control Points were acquired by QSI.
Quantum Spatial coordinated the data acquisition and performed all calibration, follow up processing, and creation of the final derived products.
Breakline File Type = SHP
Breakline Elevation Units = Meters
Downhill Treatment Applied = Monotonic (Rivers) and Flattened (Lakes)
Type of Hydro Treatment Required = Hydro-flattened
20191005
20191010
ground condition: Acquisition below aircraft free of smoke, fog and cloud cover
None planned
-123.651257
-123.012849
42.133436
41.880046
446175.625100
498933.931600
4664591.715300
4636661.411000
None
Model
Breaklines
Elevation Data
Lidar
None
Oregon
Cave Junction, Ashland, Josephine County, Jackson County, Del Norte County, Siskiyou County
Rogue River Siskiyou
No restrictions apply to these 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. Acknowledgment of the US Forest Service would be appreciated for products derived from these data.
Data covers the entire area specified for the contracted area. Breaklines were collected for lakes ~2 acres or greater and for river's greater with a nominal width of 100' or more.
All files are inspected to ensure that they conform to the specified file naming conventions, load in their correct geographic position, and conform to the project specifications for file standard and content.
Lidar Pre-Processing:
1. Review flight lines and data to ensure complete coverage of the study area and positional accuracy of the laser points.
2. Resolve kinematic corrections for aircraft position data using kinematic aircraft GPS and static ground GPS data.
3. Develop a smoothed best estimate of trajectory (SBET) file that blends post-processed aircraft position with sensor head position and attitude recorded throughout the survey.
4. Calculate laser point position by associating SBET position to each laser point return time, scan angle, intensity, etc. Create raw laser point cloud data for the entire survey in *.las format. Convert data to orthometric elevations by applying a geoid correction.
5. Import raw laser points into manageable blocks to perform manual relative accuracy calibration and filter erroneous points. Classify ground points for individual flight lines.
6. Using ground classified points per each flight line, test the relative accuracy. Perform automated line-to-line calibrations for system attitude parameters (pitch, roll, heading), mirror flex (scale) and GPS/IMU drift. Calculate calibrations on ground classified points from paired flight lines and apply results to all points in a flight line. Use every flight line for relative accuracy calibration.
7. Adjust the point cloud by comparing ground classified points to supplemental ground control points.
Base_Station_Control, SBETs, GCPs, RAW_lidar
20191010
lidar Post-Processing:
1. Classify data to ground and other client designated classifications using proprietary classification algorithms.
2. Manually QC data classification
3. After completion of classification and final QC approval, calculate NVA and VVA, and density information for the project using ground control quality check points. Single swath nominal pulse spacing (NPS) was designed to be 0.50 m at nadir. Aggregate Nominal Pulse Spacing (ANPS) was calculated to be 0.20 m using all valid first return points.
20191010
Once data processing was complete, water boundary polygons were developed using an algorithm which weights lidar-derived slopes, intensities, and return densities to detect the water's edge. The water's edge was then manually reviewed and edited as necessary. Elevations were assigned to the water’s edge through neighborhood statistics identifying the lowest lidar return from the water surface. Lakes were assigned a consistent elevation for an entire polygon while rivers were assigned consistent elevations on opposing banks and smoothed to ensure downstream flow through the entire river channel. These breaklines were incorporated into the hydro-flattened DEM by enforcing triangle edges (adjacent to the breakline) to the elevation values derived from the breakline. This implementation corrected interpolation along the hard edge. The entire water surface edge is at or below the immediate surrounding terrain. Breaklines were also used to classify all ground points within the identified water bodies to class 9 (water).
20191010
Vector
Universal Transverse Mercator
10
0.9996
123.0
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, Geoid 12B
0.01
Meters
Explicit elevation coordinate included with horizontal coordinates
20200313
20200313
Quantum Spatial, Inc.
mailing and physical
1100 Circle Blvd., NE. Suite 126
Corvallis
OR
97330
USA
(541)752-1204
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
None.
None.
None.
Unclassified.
None.
None.
None.