2019 - 2020 USGS Lidar: 8 Northwest Counties, IL

Product: These lidar data are processed Classified LAS 1.4 files, formatted to individual 1000 meter x 1000 meter tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary.

Dataset Description: This 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), Albers Equal Area, meters, and a vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to individual 1000 m x 1000 m tiles, as was tiled Intensity Imagery, and tiled bare earth DEMs; all tiled to the same 1000 m x 1000 m schema. The vegetation classes are: Low vegetation 0.5-5 feet, Medium vegetation 5-20 feet, High vegetation >20 feet. Building classified points only available in Champaign County. Vegetation classes may also include buildings or parts of buildings.

Geographic Extent: This dataset covers approximately 6367 square miles in northwestern and central Illinois and consists of 3 deliveries or blocks.

IL_8County_PlusChampaign_B1 (Work Unit 175710) - Champaign County covering approximately 1049 square miles.

IL_8County_PlusChampaign_B2 (Work Unit 176488) - Jo Daviess, Stephenson, Carroll, Ogle, Whiteside, Lee, Rock Island, and Henry counties covering approximately 5318 square miles.

IL_8County_PlusChampaign_B4 (Work Unit 216347) - Champaign County (buffer area). This block includes the area along the perimeter of IL_8County_PlusChampaign_B1 which did not extend out to the project boundary.

Ground Conditions: Lidar was collected in late 2019, early 2020 and late 2020 while no snow was on the ground, and rivers levels fluctuated.

Control Points and Checkpoints:

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 the following:

IL_8County_PlusChampaign_B1 and IL_8County_PlusChampaign_B4

A total of 34 ground control points that were used to calibrate the lidar to known ground locations established throughout the Champaign County, Illinois project area.

An additional 112 independent accuracy checkpoints, 64 in Bare Earth and Urban landcovers (64 NVA points), 48 in tall Grass/tall weeds/crops, Brush lands/short trees, Forested categories (48 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

IL_8County_PlusChampaign_B2

A total of 76 ground control points that were used to calibrate the lidar to known ground locations established throughout the Jo Daviess, Stephenson, Carroll, Ogle, Whiteside, Lee, Rock Island, and Henry counties project area.

An additional 219 independent accuracy checkpoints, 127 in Bare Earth and Urban 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.

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

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 1 meter cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.

USGS Contract No. G17PC00007 CONTRACTOR: Aerial Services, Inc. Lidar data were acquired and calibrated by the prime contractor. PRIME: Aerial Services, Inc. All follow-on processing was completed by the prime contractor.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.3",

"ldrsens" : "Leica ALS70-HP",

"ldrmaxnr" : "4",

"ldrnps" : "0.5",

"ldrdens" : "4",

"ldranps" : "0.5",

"ldradens" : "4",

"ldrfltht" : "1300",

"ldrfltsp" : "125",

"ldrscana" : "50",

"ldrscanr" : "47",

"ldrpulsr" : "394",

"ldrpulsd" : "4",

"ldrpulsw" : "0.76",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.28",

"ldrswatw" : "1212",

"ldrswato" : "30",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.3",

"ldrsens" : "Riegle LMS-Q1560",

"ldrmaxnr" : "6",

"ldrnps" : "0.5",

"ldrdens" : "4",

"ldranps" : "0.5",

"ldradens" : "4",

"ldrfltht" : "1500",

"ldrfltsp" : "130",

"ldrscana" : "60",

"ldrscanr" : "89",

"ldrpulsr" : "400",

"ldrpulsd" : "2.5",

"ldrpulsw" : "0.75",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.28",

"ldrswatw" : "1725",

"ldrswato" : "30",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.3",

"ldrsens" : "Optech Galaxy Prime",

"ldrmaxnr" : "8",

"ldrnps" : "0.5",

"ldrdens" : "4",

"ldranps" : "0.5",

"ldradens" : "4",

"ldrfltht" : "1829",

"ldrfltsp" : "150",

"ldrscana" : "40",

"ldrscanr" : "85",

"ldrpulsr" : "400",

"ldrpulsd" : "2.5",

"ldrpulsw" : "0.75",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.28",

"ldrswatw" : "1331",

"ldrswato" : "30",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS witheld bit.",

"lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare Earth Ground"

},

"lasclass" : {

"clascode" : "3",

"clasitem" : "Low Vegetation"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "Medium Vegetation"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "High Vegetation"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

},

"lasclass" : {

"clascode" : "20",

"clasitem" : "Ignored Ground"

}

}}

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners.

Data is available online for bulk and custom downloads.

None

Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations.

Waypoint's Inertial Explorer version 8.60; Leica's CloudPro version 1.2.4; Applanix PosPac 8.2; RiProcess; RiAnalyze; Optech’s LMS; BayesMap-StripAlign; MicroSatation Connect version 10.14.02.01; TerraSolid TerraMatch version019.002,TerraModel version 019.008, TerraScan version 019.008; Windows 10 Operating \\server\directory path\*.las 3.36TB

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class.

USGS Determined Vertical Accuracy:

Non-Vegetated Vertical Accuracy (NVA) = 5 cm RMSE

Vegetated Vertical Accuracy (VVA) = 12.08 cm at 95th Percentile

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Data covers the entire area specified for this project.

Data is backed up to tape and to cloud storage.

The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tile (EPT) files hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.