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LiDAR Elevation Data: Outagamie County, WI 2018

Identification Information

Citation
Title
LiDAR Elevation Data: Outagamie County, WI 2018
Originator
U.S. Geological Survey
Creation Date
2018-04-30
Publication Date
2018-04-30
Edition
2018
Geospatial Data Presentation Form
mapDigital
Abstract
This data represents LiDAR elevation information for Outagamie County, Wisconsin in 2018. The following derivative products are available: Classified LAS, Hydro breaklines, Countywide DEM (UTM16), Tiled DEM. [These lidar data are processed Classified LAS 1.4 files, formatted to 4610 individual 1000 m x 1000 m tiles; used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. Geographic Extent: 3 counties in Wisconsin, covering approximately 1622 total square miles. Dataset Description: The Wisconsin 3 County 2018 QL2 LiDAR project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.71 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 1.3. The data were developed based on a horizontal projection/datum of NAD 1983 2011 UTM Zone 16N, Meter and vertical datum of NAVD88 GEOID12B, Meter. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 4610 individual 1000 m x 1000 m tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1000 m x 1000 m schema. Continuous breaklines were produced in Esri file geodatabase format.Ground Conditions: LiDAR was collected in spring 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 37 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 125 independent accuracy checkpoints, 69 in Bare Earth and Urban landcovers (69 NVA points), 56 in Tall Weeds categories (56 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.]
Purpose
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.
Supplemental Information
Data is available for download from WisconsinView: https://web.s3.wisc.edu/wsco-wisconsinview/lidar/Outagamie/Outagamie_2018_TNM_Download/ General metadata can be viewed here: https://www.fisheries.noaa.gov/inport/item/58851
Temporal Extent
Time Instant
2018-04-30T00:00:00
Bounding Box
West
-88.746068
East
-88.180537
North
44.594486
South
44.201241
ISO Topic Category
elevation
Place Keyword
Outagamie County
Wisconsin
Place Keyword Thesaurus
GNS
Theme Keyword
Digital elevation models
Theme Keyword Thesaurus
LCSH
Theme Keyword
Lidar
Grids
Surface models
Terrain models
Relief models
Topography
Elevations
Theme Keyword Thesaurus
Legal Constraints
Use Limitation
Although this data is being distributed by the University of Wisconsin-Madison, no warranty expressed or implied is made by the University as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the University in the use of this data, or related materials.
Status
completed
Maintenance and Update Frequency
unknown
Language
eng
Credit
U.S. Geological Survey
Point of Contact
Contact
U.S. Geological Survey

Spatial Reference Information

Reference System Identifier
Code
6345
Code Space
EPSG
Version
10.084

Data Quality Information

Completeness Commission
Lineage
Process Step
Description
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 technicians 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.
Process Step
Description
LAS Point Classification: The point classification was performed as described below. The bare earth surface was manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface was finalized, it was then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) LiDAR data inside of the Lake Pond and Double Line Drain hydro-flattened breaklines were then classified to Water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 meter was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 20). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to approved classes by USGS. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. Due to software limitations within TerraScan, these classes were used to trip the withheld bit within various software packages. These processes were reviewed and accepted by USGS through numerous conference calls and pilot study areas. All data were manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper was used as a final check of the bare earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for both the All Point Cloud Data and the Bare Earth. Quantum Spatial, Inc. proprietary software was used to perform final statistical analysis of the classes in the LAS files, on a per tile level to verify final classification metrics and full LAS header information.
Process Step
Description
Provided access to archived data at UW-Madison.
Process Date
2023-06-14T00:00:00

Distribution Information

Format Name
Various
Format Version
1.0
Distributor
UW-Madison
Online Access
https://web.s3.wisc.edu/wsco-wisconsinview/lidar/Outagamie/Outagamie_2018_TNM_Download/
Protocol
WWW:DOWNLOAD-1.0-http--download
Name
WisconsinView
Function
download

Spatial Representation Information

Vector
Topology Level
geometryOnly
Vector Object Type
composite
Vector Object Count
7

Metadata Reference Information

Hierarchy Level
dataset
Metadata File Identifier
DC084240-8312-4083-BC4F-1BE7E5E4C378
Metadata Point of Contact
Name
Arthur H. Robinson Map Library
Position Name
Metadata Technician
Delivery Point
550 N. Park Street
City
Madison
Administrative Area
WI
Postal Code
53706
Country
US
Email
askmap@library.wisc.edu
Phone
608-262-1471
Metadata Date Stamp
2023-06-20
Metadata Standard Name
ISO 19139 Geographic Information - Metadata - Implementation Specification
Metadata Standard Version
2007
Character Set
utf8
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