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LiDAR Elevation Data (QL1 and QL2): Iron County, WI 2019
- Identification Information
- Spatial Reference Information
- Data Quality Information
- Distribution Information
- Metadata Reference Information
Identification Information
- Citation
- Title
- LiDAR Elevation Data (QL1 and QL2): Iron County, WI 2019
- Originator
- U.S. Geological Survey
- Publication Date
- 2020-10-07
- Edition
- 2019
- Geospatial Data Presentation Form
- modelDigital
- Collection Title
- Coastal
- Abstract
- This data represents QL1and QL2 LiDAR elevation information for Iron County, Wisconsin in 2019. The following derivative products are available: classified LAS, hydro breaklines, tiled DEM, tiled DSM, and intensity images. QL1 refers to higher resolution data, with 8 points per square meter. QL2 refers to lower resolution data, with 2 points per square meter.[QL1 and QL2 Products: These lidar data are processed Classified LAS 1.4 files, formatted to 612 individual 2500 ft x 2500 ft tiles; used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary; These are Digital Elevation Model (DEM) data for Wisconsin as part of the required deliverables for the WI AshlandIronFlorence - Iron QL1 Lidar, Work Package 183663, Work Unit 205763 project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 2 foot hydro-flattened Raster DEM; These are Digital Surface Model (DSM) data for Wisconsin as part of the required deliverables for the WI AshlandIronFlorence - Iron QL1 Lidar, Work Package 183663, Work Unit 205763 project. First return lidar points were used to create a 2 foot raster DSM; Breakline data is used to hydroflatten the DEMs created for the WI AshlandIronFlorence - Iron QL1 Lidar, Work Package 183663, Work Unit 205763 project. Breaklines are reviewed against LiDAR intensity imagery to verify completeness of capture. Geographic Extent QL1: 3 counties in Wisconsin, covering approximately 123 total square miles. Geographic Extent QL2: 5 counties in Wisconsin, covering approximately 720 total square miles. QL1 Dataset Description: The WI AshlandIronFlorence - Iron QL1 Lidar, Work Package 183663, Work Unit 205763 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 Specification, Version 1.3. The data were developed based on a horizontal projection/datum of NAD 1983 2011 WISCRS Iron Feet, Foot US and vertical datum of NAVD88 Geoid 12b, Foot US. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 612 individual 2500 ft x 2500 ft tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 2500 ft x 2500 ft schema. Continuous breaklines were produced in Esri file geodatabase format. QL2 Dataset Description: Iron QL2 Lidar, Work Package 183663, Work Unit 209903 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 WISCRS Iron Feet, Foot US and vertical datum of NAVD88 Geoid 12b, Foot US. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 3369 individual 2500 ft x 2500 ft tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 2500 ft x 2500 ft schema. Continuous breaklines were produced in Esri file geodatabase format. Ground Conditions: LiDAR was collected in fall 2019, 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 0 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 0 independent accuracy checkpoints, 0 in Bare Earth and Urban landcovers (0 NVA points), 0 in Tall Weeds categories (0 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
- This data is intended for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. [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
- This is an archived copy of the data held at UW-Madison. Detailed metadata for all lidar derivative products is available from: https://bin.ssec.wisc.edu/pub/wisconsinview/lidar/Iron/Iron_2019_3DEP_Delivery in the "reports" folder.
- Temporal Extent
- Currentness Reference
- Ground condition
- Time Period
- Begin
- 2019-10-26T00:00:00
- End
- 2019-10-30T00:00:00
- Bounding Box
- West
- -90.5519644546
- East
- -90.3841447685
- North
- 46.5968234475
- South
- 46.3215292622
- ISO Topic Category
- elevation
- Place Keyword
- Iron County
-
Wisconsin
- Place Keyword Thesaurus
- Theme Keyword
- Model
- LAS Point Cloud
- Remote Sensing
- Elevation Data
-
LiDAR
- Theme Keyword Thesaurus
- 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.]
- Legal Constraints
- Access Restrictions
- otherRestrictions
- Other Restrictions
- No restrictions apply to these data.
- Status
- completed
- Maintenance and Update Frequency
- asNeeded
- Language
- eng
- Credit
- U.S. Geological Survey
- Point of Contact
- Contact
- Quantum Spatial, Inc.
- Delivery Point
- 523 Wellington Way
- City
- Lexington
- Administrative Area
- KY
- Postal Code
- 40503
- Country
- US
- jmonge@quantumspatial.com
- Phone
- 859-277-8700
Spatial Reference Information
- Reference System Identifier
- Code
- 7611
- Code Space
- EPSG
- Version
- 10.076
Data Quality Information
- Lineage
- Statement
- Data available from WisconsinView,org
- 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 Date
- 2020-10-07T00:00:00
- 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. 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 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 Date
- 2020-10-07T00:00:00
- Source
- Title
- Ground Control for the WI AshlandIronFlorence - Iron QL1 Lidar, Work Package 183663, Work Unit 205763 Project
- Publication Date
- 2020-10-07
- Originator
- Ayres
- Publisher
- Ayres
- Description
- This data source was used (along with airborne GPS/IMU data) to georeference the LiDAR point cloud data.
Distribution Information
- Format Name
- LAS, GeoTIFF
- Distributor
- UW-Madison
- Online Access
- https://bin.ssec.wisc.edu/pub/wisconsinview/lidar/Iron/Iron_2019_3DEP_Delivery
- Protocol
- WWW:DOWNLOAD-1.0-http--download
- Name
- WisconsinView.org
- Function
- download
Metadata Reference Information
- Hierarchy Level
- dataset
- Metadata File Identifier
- 09569CDF-3544-4A74-AEE4-098A7E3A9B6A
- Metadata Date Stamp
- 2022-11-18
- Metadata Standard Name
- ISO 19139 Geographic Information - Metadata - Implementation Specification
- Metadata Standard Version
- 2007
- Character Set
- utf8