2022 USGS QL1 Lidar DEM: Bayfield, Burnett, Douglas, Jackson, Oneida, Trempealeau, Vilas, and Wood Counties, WI

Original Dataset Product:

These are Digital Elevation Model (DEM) data for Wisconsin as part of the required deliverables for the WI_12County_B22 project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 1 foot hydro-flattened Raster DEM.

Original Dataset Geographic Extent: 8 counties in Wisconsin

WI_12County_1 (Work Unit 230107) - covering approximately 1027 square miles in Vilas County

WI_12County_2 (Work Unit 300205) - covering approximately 816 square miles in Wood County

WI_12County_7 (Work Unit 300210) - covering approximately 750 square miles in Trempealeau County

WI_12County_8 (Work Unit 300211) - covering approximately 1240 square miles in Oneida County

WI_12County_9 (Work Unit 300212) - covering approximately 1010 square miles in Jackson County

WI_12County_10 (Work Unit 300213) - covering approximately 1352 square miles in Douglas County

WI_12County_11 (Work Unit 300214) - covering approximately 891 square miles in Burnett County

WI_12County_12 (Work Unit 300215) - covering approximately 1527 square miles in Bayfield County

Original Dataset Description: The WI_12County_B22 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 Base Specifications 2021, Revision A. The data were developed based on a horizontal projection/datum of NAD 1983 2011 WISCRS, Foot US and vertical datum of NAVD88 Geoid 18, Foot US. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to individual 4500 ft x 4500 ft tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 4500 ft x 4500 ft schema. Continuous breaklines were produced in Esri file geodatabase format.

Ground Conditions: LiDAR was collected in spring 2022, while no snow was on the ground and rivers were at or below normal levels.

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

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 foot 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.

Raster File Type = GeoTIFF; Bit Depth/Pixel Type = 32-bit float; Raster Cell Size = 1 foot; Interpolation or Resampling Technique = Triangulated Irregular Network (TIN), Linear Interpolation, Proprietary; Required Vertical Accuracy = 0.196

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.

MicroStation Connect; TerraScan Version 20.011; STRIPALIGN 2.21 ; TerraModeler Version 20.004; GeoCue Version 2017.1.14.1; Esri ArcGIS 10.6; Global Mapper 19/20; RiProcess 1.8.6; Windows 10 Operating System

\\point_cloud\tilecls\*.las

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% of the time.

WI_12County_1 (Work Unit 230107) - Vilas County, WI_12County_8 (Work Unit 300211) - Oneida County

Based on a flying altitude of 1606 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, this project was compiled to meet 0.18 meter horizontal accuracy at the 95% confidence level (0.10 m RMSEr).

WI_12County_2 (Work Unit 300205) - Wood County

Based on an average flying altitude of 1452 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, this project was compiled to meet 0.16 meter horizontal accuracy at the 95% confidence level (0.09 m RMSEr).

WI_12County_7 (Work Unit 300210) - Trempealeau County

Based on a flying altitude of 1317 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, this project was compiled to meet 0.14 meter horizontal accuracy at the 95% confidence level (0.08 m RMSEr).

WI_12County_9 (Work Unit 300212) - Jackson County

Based on a flying altitude of 1311 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, this project was compiled to meet 0.14 meter horizontal accuracy at the 95% confidence level (0.083 m RMSEr).

WI_12County_10 (Work Unit 300213) - Douglas County

Based on a flying altitude of 1,663 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, this project was compiled to meet 0.18 meter horizontal accuracy at the 95% confidence level (0.104 m RMSEr).

WI_12County_11 (Work Unit 300214) - Burnett County

Based on a flying altitude of 1767 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, this project was compiled to meet 0.19 meter horizontal accuracy at the 95% confidence level (0.11 m RMSEr).

WI_12County_12 (Work Unit 300215) - Bayfield County

Based on a flying altitude of 1690 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.015 meters, this project was compiled to meet 0.18 meter horizontal accuracy at the 95% confidence level (0.11 m RMSEr).

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class.

USGS DEM Determined Vertical Accuracy:

Tested NVA RMSEz = 2.73 cm

Tested NVA Accuracy z at 95% confidence interval (RMSEz * 1.96) = 5.4 cm

Tested 95th percentile value for VVA is : 15.16 cm

For more information see the USGS project report and the lidar reports. The links to these reports are provided in the URL section of this metadata record.

Datasets contain complete coverage of tiles. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. There are no void areas or missing data. The raw point cloud is of good quality and data pass Non-Vegetated Vertical Accuracy specifications.

Data cover the entire area specified for this project.

Data is backed up to cloud storage.

The NOAA Office for Coastal Management (OCM) ingested references to the USGS GeoTIFF files that are hosted on Amazon Web Services (AWS), into the Digital Coast Data Access Viewer (DAV). The DAV accesses the raster data as it resides on AWS.