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LiDAR Elevation Data: Crawford County, WI 2021

Identification Information

Citation
Title
LiDAR Elevation Data: Crawford County, WI 2021
Originator
U.S. Geological Survey
Creation Date
2021-04-22
Publication Date
2021-04-22
Edition
2021
Geospatial Data Presentation Form
mapDigital
Abstract
This data represents LiDAR elevation information for Crawford County, Wisconsin in 2021. The following derivative products are available: Classified LAS, Hydro Breaklines, Intensity images (tiled) DEM (tiled), Tile index. Also included are several countywide products created by the WisconsinView Partners - the WI Department of Administration’s Geographic Information Office in collaboration with the UW-Madison Space Science and Engineering Center’s (SSEC) WisconsinView repository. Original lidar data in tiled format from federal (USGS 3DEP) and/or local county lidar projects were used to create countywide mosaics of specific datasets such as DEMS, Intensity values and DSMs in various projections and coordinate systems. [These lidar data are processed Classified LAS 1.4 files, formatted to 897 individual 4500 ft x 4500 ft tiles; used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. Geographic Extent: 6 counties in Wisconsin, covering approximately 606 total square miles. Dataset Description: The 37876_WI_Statewide_2021_B21 project, Work Unit 300037 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, 2020 rev. A. The data were developed based on a horizontal projection/datum of NAD 1983 2011 WISCRS Crawford Feet, Foot US and vertical datum of NAVD88 Geoid 18, Foot US. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 897 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 2021, while no snow was on the ground and rivers were at or below normal levels. Digital Elevation Model (DEM) data for Wisconsin as part of the required deliverables for the 37876_WI_Statewide_2021_B21 project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 2 foot hydro-flattened Raster DEM.
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 2 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.
Supplemental Information
Data is available for download from: https://web.s3.wisc.edu/wsco-wisconsinview/lidar/Crawford/Crawford_2021_3DEP_Delivery/ Detailed, original metadata accompanying this LiDAR data is available inside the ‘Metadata’ folder from WisconsinView. https://web.s3.wisc.edu/wsco-wisconsinview/lidar/Crawford/Crawford_2021_3DEP_Delivery/Metadata/
Temporal Extent
Time Instant
2021-04-22T00:00:00
Bounding Box
West
-91.2166161317
East
-90.6640929897
North
43.4256955107
South
42.9863753979
ISO Topic Category
elevation
Place Keyword
Crawford County
Wisconsin
Place Keyword Thesaurus
GNS
Theme Keyword
Digital elevation models
Theme Keyword Thesaurus
LCSH
Theme Keyword
Lidar
Contours
Grids
Surface models
Terrain models
Hydrography
Topography
Elevations
Theme Keyword Thesaurus
LCSH
Resource Constraints
Use Limitation
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 their limitations. Acknowledgement of the organization providing these data to the public would be appreciated for products derived from these data.
Status
completed
Maintenance and Update Frequency
unknown
Language
eng
Credit
U.S. Geological Survey
Point of Contact
Contact
U.S. Geological Survey
Point of Contact
Contact
NV5 Geospatial
Position Name
Contractor

Spatial Reference Information

Reference System Identifier
Code
8197
Code Space
EPSG
Version
9.7

Data Quality Information

Completeness Commission
Lineage
Process Step
Description
Hydro-Flattened Breakline Processing: Class 2 (ground) LiDAR points were used to create a bare earth surface model. The surface model was then used to heads-up digitize 2D breaklines of inland streams and rivers with a 100-foot nominal width and inland ponds and lakes of 2 acres or greater surface area. Elevation values were assigned to all Inland Ponds and Lakes, Inland Pond and Lake Islands, Inland Stream and River Islands, using TerraModeler functionality. Elevation values were assigned to all inland streams and rivers using NV5 Geospatial proprietary software. All Ground (ASPRS Class 2) LiDAR data inside of the collected inland breaklines were then classified to Water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 3.0 foot was also used around each hydro-flattened feature. These points were moved from ground (ASPRS Class 2) to Ignored Ground (ASPRS Class 20). The breakline files were then translated to Esri file geodatabase format using Esri conversion tools. Breaklines were reviewed against LiDAR intensity imagery to verify completeness of capture. All breaklines were then compared to TINs (triangular irregular networks) created from ground only points prior to water classification. The horizontal placement of breaklines was compared to terrain features and the breakline elevations were compared to LiDAR elevations to ensure all breaklines matched the LiDAR within acceptable tolerances. Some deviation was expected between breakline and LiDAR elevations due to monotonicity, connectivity, and flattening rules that were enforced on the breaklines. Once completeness, horizontal placement, and vertical variance were reviewed, all breaklines were reviewed for topological consistency and data integrity using a combination of Esri Data Reviewer tools and proprietary tools.

Distribution Information

Format Name
Various
Format Version
1.0
Distributor
University of Wisconsin-Madison
Online Access
https://web.s3.wisc.edu/wsco-wisconsinview/lidar/Crawford/Crawford_2021_3DEP_Delivery/
Protocol
WWW:DOWNLOAD-1.0-http--download
Name
WisconsinView.org
Function
download

Metadata Reference Information

Hierarchy Level
dataset
Metadata File Identifier
FA2B2E58-CAF5-4D02-804D-C4DB004E29E2
Metadata Point of Contact
Name
Arthur H. Robinson Map Library
Position Name
metadata technician
Delivery Point
310 Science Hall
City
Madison
Administrative Area
WI
Postal Code
53706
Country
US
Email
askmap@library.wisc.edu
Phone
608-262-1471
Metadata Date Stamp
2017-06-28
Metadata Standard Name
ISO 19139 Geographic Information - Metadata - Implementation Specification
Metadata Standard Version
2007
Character Set
utf8
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