USFS 2020 Lidar: Wallowa-Whitman National Forest

Product: These lidar data are processed Classified LAS 1.4 files, formatted to 1773 individual 1000 m x 1000 m tiles.

Geographic Extent: 7 counties in Oregon, covering approximately 684 total square miles.

Dataset Description: The Wallowa-Whitman National Forest project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 1.3. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 1773 individual 1000 m x 1000 m tiles. Continuous breaklines were produced in Esri file geodatabase format.

Ground Conditions: Lidar was collected in summer 2020, while no snow was on the ground and rivers were at or below normal levels. Twenty-seven independent accuracy checkpoints, 27 in Bare Earth and Urban landcovers (27 NVA points) were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

The original lidar specification information has been retained below. However, the class system does not match the data as received by NOAA from USFS, nor the current class system. See the processing lineage for more detail.

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 and raster DEMs. The purpose of these LiDAR data was to produce high accuracy 3D hydro-flattened digital elevation models (DEMs) with a 0.5 meter cell size.

Contract No. 1205M619C0019, CONTRACTOR: Quantum Spatial, Inc.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Specification v1.3",

"ldrsens" : "Riegl VQ1560i",

"ldrmaxnr" : "unlimited",

"ldrnps" : "0.35",

"ldrdens" : "8.0",

"ldranps" : "0.35",

"ldradens" : "8.16",

"ldrfltht" : "1950",

"ldrfltsp" : "145",

"ldrscana" : "29",

"ldrscanr" : "102",

"ldrpulsr" : "593",

"ldrpulsd" : "3",

"ldrpulsw" : "0.35",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.18",

"ldrswatw" : "2162.0",

"ldrswato" : "55",

"ldrgeoid" : "Geoid 12b",

"ldrcrs" : "NAD 1983 USFS R6 Albers, Meter"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0.0533",

"rawnvan" : "27",

"clsnva" : "0.0525",

"clsnvan" : "27",

"clsvva" : "0.0",

"clsvvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"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" : "Low Noise"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

},

"lasclass" : {

"clascode" : "21",

"clasitem" : "Snow (where identifiable)"

}

}}

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

Data is available online for bulk or custom downloads

None

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.

MicroStation Version Connect; TerraScan Version 20.011; TerraModeler Version 20.004; GeoCue Version 2017.1.14.1; Esri ArcGIS 10.6; Global Mapper 19/20; RiProcess 1.8.5; Windows 10 Operating System

\\point_cloud\tilecls\*.las

The specifications require that only nonvegetated vertical accuracy (NVA) be computed for raw LiDAR data swath files. The vertical accuracy was tested with 27 independent survey points located in open terrain. These check points were not used in the calibration or post processing of the LiDAR data. The survey check points were distributed throughout the project area.Quantitative value: 0.0533, Test that produced the value:

Tested 0.0533 meters NVA at a 95% confidence level using 27 independent survey points located in open terrain. The survey check points were distributed throughout the project area. The 27 independent check points 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. The root mean square error vertical (RMSEz) was computed to be 0.0272 meters. AccuracyZ has been tested to meet 19.0 cm NVA at 95-percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using American Society of Photogrammetry and Remote Sensing (ASPRS) Guidelines.

These 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 the data pass Non-Vegetated Vertical Accuracy specifications.

Data cover the entire area specified for this project.

Data is backed up to tape and to cloud storage.