2021 USGS Lidar: McKenzie River, OR

Product: Classified LAS 1.4 files, formatted to 2348 individual 3000ft X 3000ft tiles covering the McKenzie River 3DEP Lidar project area.

Geographic Extent: This dataset and derived products encompass an area covering approximately 425,020 acres of the McKenzie River in Oregon.

Dataset Description: The McKenzie River 3DEP Lidar project called for the planning, acquisition, and processing of lidar data collected to Quality Level 1 (QL1) standards. Project specifications are based on the U.S. Geological Survey National Geospatial Program LIDAR Base Specification, Version 2.1. The data was developed based on the NAD83 2011 horizontal datum and the NAVD88 Geoid 18 vertical datum. Data was projected in Oregon Statewide Lambert: international feet. Lidar data was delivered as calibrated and classified LAS 1.4 files. Non-Vegetated Vertical Accuracy (NVA) was assessed using 49 check points located on bare earth in clear, unobstructed areas. Vegetated Vertical Accuracy (VVA) was assessed using 36 check points in Shrub, Forest, Tall Grass landcover types. Single swath nominal pulse spacing (NPS) was designed to be 0.5 m at nadir. Aggregate Nominal Pulse Spacing (ANPS) was calculated to be 0.239 using all valid first return points. Derived products include: Intensity Imagery, Hydro-flattened Bare Earth Digital Elevation Models (DEMs), Highest Hit Digital Surface Models (DSMs), and 3D waters edge breaklines.

Ground Condition: Ground condition was free of snow and acquisition occured free of smoke, fog and cloud cover.

This metadata supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the 3D Elevation Program and the McKenzie River 3DEP Lidar contract. The lidar point cloud data were used to create classified lidar LAS files, intensity images, hydro-flattened DEMs, highest hit DSMs, and 3D breaklines of rivers and lakes within the study area.

USGS Contract No. G16PC00016

CONTRACTOR: NV5 Geospatial

Ground Control Points were acquired and calibrated by NV5 Geospatial

All lidar data acquisition, calibration, and follow-on processing were completed by NV5 Geospatial.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program LIDAR Base Specification, Version 2.1",

"ldrsens" : "Riegl 1560ii-S",

"ldrmaxnr" : "15",

"ldrnps" : "0.5",

"ldrdens" : "4",

"ldranps" : "0.239",

"ldradens" : "17.50",

"ldrfltht" : "2365",

"ldrfltsp" : "145",

"ldrscana" : "58.5",

"ldrscanr" : "Uniform Point Spacing",

"ldrpulsr" : "721",

"ldrpulsd" : "3",

"ldrpulsw" : "0.404",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.17",

"ldrswatw" : "2649",

"ldrswato" : "55",

"ldrgeoid" : "Geoid 18"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "49"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points are 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" : "8",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

},

"lasclass" : {

"clascode" : "20",

"clasitem" : "Ignored Ground Near Breaklines"

}

}}

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

Data is available online for bulk and 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.

PosPac 7.1, Microstation CONNECT version, TerraScan Version 20, TerraModeler Version 20, TerraMatch Version 20, ESRI ArcGIS 10.8, Windows 10 Operating System

Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and INS derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95 percent of the time. Based on a flying altitude of 2,365 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.019 meters, this project was produced to meet 0.85 feet (0.26 m) horizontal accuracy at the 95% confidence level or 0.15 m RMSEr.

NV5 Determined Vertical Accuracy

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class. The NVA was tested with 49 independent check points located in open terrain and distributed throughout the project as feasible. These check points were not used in the calibration or post processing of the lidar point cloud data. Specifications for this project require that the NVA be 0.196 meters or better AccuracyZ at 95% confidence level. The 49 independent NVA check points were surveyed using the closed level loop technique. Elevations interpolated from the unclassified lidar surface were compared to the elevation values of the surveyed NVA check points. The RMSE was computed to be 0.029 meters resulting in an AccuracyZ at the 95% confidence level of 0.057 meters. NVA AccuracyZ has been tested and meets the required 0.196 meter NVA at 95% confidence level using (RMSEz * 1.9600) for the unclassified lidar point cloud as defined by the National Standards for Spatial Data Accuracy (NSSDA) and herein reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

USGS Determined Vertical Accuracy

Non-Vegetated Vertical Accuracy (NVA) = 2.9 cm RMSE

Vegetated Vertical Accuracy (VVA) = 23.08 cm at the 95th Percentile

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 data passes Non-Vegetated Vertical Accuracy specifications.

Classified LAS files were tested by NV5 for vertical accuracy. All data is seamless from one tile to the next, no gaps or no data areas.

Data is backed up to tape and to cloud storage.

The USGS data set, 2021 McKenzie River, lidar was ingested into the Data Access Viewer for custom product generation by leveraging USGS hosted Entwine Point Tiles.