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LiDAR Elevation Data: Crawford County, WI 2021
- Identification Information
- Spatial Reference Information
- Data Quality Information
- Distribution Information
- Metadata Reference Information
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
- 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