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To acquire QL2+ lidar detailing surface elevation data, and vegetation for use in conservation planning design, research, floodplain mapping, dam safety assessment and elevation modeling, ect. 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 this lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2 US survey feet cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. |
| summary:
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To acquire QL2+ lidar detailing surface elevation data, and vegetation for use in conservation planning design, research, floodplain mapping, dam safety assessment and elevation modeling, ect. 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 this lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2 US survey feet cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. |
| accessInformation:
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Natural Resources Conservation Service (NRCS), United States Geological Survey (USGS),Illinois States Geological Survey (ISGS), Aerial Services Inc. |
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| typeKeywords:
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["Data","Service","Image Service","ArcGIS Server"] |
| description:
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<DIV STYLE="text-align:Left;"><DIV><P><SPAN>These acquisitions of the LiDAR data and its derivatives were made possible by funding from NRCS and USGS. The final digital terrain model was produced by ISGS after their QAQC process on the delivered data from ASI. There were some raster errors that were cleaned up within this process and noted errors in the classified las tiles data collection, these errors were reported and planned to be corrected. The contracted product acquired included: bare earth hydro-flattened DEMs .img files, hydro breaklines, processed Classified LAS 1.4 files, intensity images, along with vendor provided metadata and vertical accuracy reports. Geographic Extent: Jo Daviess, Stephenson, Carroll, Ogle, Whiteside, Lee, Rock Island, and Henry Counties Illinois, covering approximately 5318 square miles. Dataset Description: Illinois 8 county 2019 Lidar Dataset Description: Block 3_IL_8 County, Illinois 2019 Lidar project called for the planning, acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing of 0.5 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3. The data was developed based on a horizontal projection/datum of NAD83(2011), State Plane Coordinat System Illinois West (FIPS 1202), United States Survey Feet, and a vertical datum of NAVD88 (GEOID12B), US survey feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 37,739 individual 2000 US survey feet x 2000 US survey feet tiles, and 37,738 tiled Intensity Imagery, and 37,739 tiled bare earth DEMs; all tiled to the same 2000 US survey feet x 2000 US survey feet schema. Tile 2075_1735 is located within a water body with no reflectance measured within the tile boundary, so no intensity image was produced for that tile. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3; Quality Level 2+. The data was developed based on a horizontal projection/datum of NAD83(2011), State Plane Coordinat System Illinois West (FIPS 1202), US survey feet, and a vertical datum of NAVD88 (GEOID12B), US survey feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 37,739 individual 2000 US survey feet x 2000 US survey feet tiles, as tiled Intensity Imagery, and as tiled bare earth DEMs; all tiled to the same 2000 x 2000 US survey feet schema. Ground Conditions: Lidar was collected in late 2019, early 2020 and late 2020 while no snow was on the ground, and rivers levels fluctuated. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Subcontractor, Surveying and Mapping, LLC (SAM) established a total of 76 ground control points that were used to calibrate the lidar to known ground locations established throughout the Block 3_IL_8 County project area. An additional 219 independent accuracy checkpoints, 127 in Bare Earth and Uraban landcovers (127 NVA points), 92 in tall Grass/tall weeds/crops, Brush lands/short trees, Forested categories (92 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.</SPAN></P></DIV></DIV> |
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<DIV STYLE="text-align:Left;"><DIV><P><SPAN>ISGS information is the property of and copyrighted by the Board of Trustees of the University of Illinois with all rights reserved. University copyright policy is stated in the General Rules Concerning University Organization and Procedure, Article III, Section 4. A link is provided in the Cross References section. Individuals or entities may make fair use of copyrighted ISGS material, such as reproducing a single figure or table, or using a brief text quotation, without obtaining formal permission, but in all cases the Illinois State Geological Survey must be credited as the source of the material. To reproduce ISGS information beyond the fair use standard, permission must be obtained from the ISGS Information Office, 615 East Peabody Drive, Champaign, Illinois 61820, 217-333-4747, isgs@isgs.illinois.edu. License fees and a license agreement may be required, depending on the proposed usage. Any use of these data is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section. Map information is to be used at a scientifically and cartographically appropriate scale, that is, at a scale no greater than indicated on the map or as described in the documentation of the map or map data. Map information is not appropriate for, and is not to be used as, a geodetic, legal, or engineering base. Map information has no legal basis in the definition of boundaries or property lines and is not intended as a substitute for surveyed locations such as can be determined by a registered Public Land Surveyor. The data do not replace the need for detailed site-specific studies.. 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 its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.</SPAN></P></DIV></DIV> |
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| title:
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IL_Henry_DTM_2020 |
| type:
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Image Service |
| url:
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https://isgs-datagis1.ad.uillinois.edu:6443/arcgis/admin |
| tags:
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["Model","LAS Point Cloud","Remote Sensing","Elevation Data","Lidar"] |
| culture:
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en-US |
| name:
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IL_Henry_DTM_2020 |
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| spatialReference:
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NAD_1983_2011_StatePlane_Illinois_West_FIPS_1202_Ft_US |