2014 UIUC Lidar: Will County, IL

This dataset is 1 ppsm lidar point cloud data and derivative models of Will County, Illinois. Will County is approximately 840 square miles (2175 square kilometers) in north eastern Illinois. Data was collected at a nominal pulse spacing (NPS) of 1 meter.

Data acquisition, processing and assessment is compliant with procedures and methods stated in U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 1.0 and Federal Emergency Management Agency Procedure Memorandum 61.

This dataset consists of lidar LAS swath files and tiled LAS files. Tiled LAS files contain lidar point information which has been calibrated, controlled, and classified.

Quantum Spatial Project No: 1140310.02

Lidar data collection is used to produce high accuracy surface models of Will County, Illinois in accordance with project requirements.

The lidar point cloud data is used to create surface models as requested; classified lidar LAS files, Hydro-flattened bare-earth Digital Elevation Models (DEM), shapefiles of breaklines representative of surface hydro features and a ESRI geodatabase of all deliverables.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS NGP Base Specification v1",

"ldrsens" : "Leica ALS70 Serial Number 7161 ",

"ldrmaxnr" : "4 returns per pulse",

"ldrnps" : "0.64 meters",

"ldrdens" : "2.44 points per meter squared",

"ldrfltht" : "1900 meters",

"ldrfltsp" : "150 knots",

"ldrscana" : "40.0 degrees",

"ldrscanr" : "40.9 Hz",

"ldrpulsr" : "273600 Hz",

"ldrpulsd" : "4 nanoseconds",

"ldrpulsw" : "0.45 meters, 1/e^2",

"ldrwavel" : "1064 nanometers",

"ldrmpia" : "1 [enabled]",

"ldrbmdiv" : "0.15 milliradians",

"ldrswatw" : "1455.88 meters",

"ldrswato" : "17.25%",

"ldrcrs" : "NAD_1983_2011_StatePlane_Illinois_East_FIPS_1201_Ft_US",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldraccur" : {

"ldrchacc" : "1.00 feet",

"rawfva" : "0.402 feet",

"clscva" : "0.527 feet",

"clssvas" : {

"svalctyp" : "Open Terrain survey points compared to DEM. 95th percentile",

"svavalue" : "0.373 feet"

},

"clssvas" : {

"svalctyp" : "Urban survey points compared to DEM. 95th percentile",

"svavalue" : "0.469 feet"

},

"clssvas" : {

"svalctyp" : "Tall Grass survey points compared to DEM. 95th percentile",

"svavalue" : "0.517 feet"

},

"clssvas" : {

"svalctyp" : "Brush survey points compared to DEM. 95th percentile",

"svavalue" : "0.627 feet"

},

"clssvas" : {

"svalctyp" : "Forest survey points compared to DEM. 95th percentile",

"svavalue" : "0.504 feet"

}

},

"lasinfo" : {

"lasver" : "1.2",

"lasprf" : "1",

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

",

"lasolap" : "There are not Overlap class points in this data.

",

"lasintr" : "8-bit",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Undetermined/Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare-earth"

},

"lasclass" : {

"clascode" : "3",

"clasitem" : "Low Vegetation"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "Medium Vegetation"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "High Vegetation"

},

"lasclass" : {

"clascode" : "6",

"clasitem" : "Buildings"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "All noise"

},

"lasclass" : {

"clascode" : "8",

"clasitem" : "Model Keypoints"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored ground"

}

}}

In no event shall the creators, custodians, or distributors of these data be liable for any damages arising out of its use, or from the inability of the customer to use these data for their intended application.

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 or 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.

ALS Post Processor 2.75 Build#25; GeoCue Version 13.1.45.1; Windows 7 Operating System

Project specifications require that vertical accuracy, as RMSE, of lidar data be less than 9.25 cm in open terrain. Vertical accuracy is determined by comparison of elevation of the ground survey points to DEMs derived from the lidar points. Differences are calculated to establish a RSME.

The FVA is determined using ground survey points collected in "Open Terrain" compared to elevation values of a DEM derived from the final lidar points classified as bare earth. Differences in elevations are calculated to determine a RSME. The RMSE value is multiplied by 1.96 to establish the FVA.

Quantitative value: 0.21 feet (6.25 cm) RMSE calculated by comparison of open terrain survey points to DEM elevations. FVA tested 0.40 feet (12.25 cm) vertical accuracy at 95-percent confidence level., Test that produced the value:

The vertical accuracy meets the requirement of RMSE less than 9.25 cm and of a FVA less than 18.13 cm.

These data files include all data points collected.

No points have been removed or excluded.

The raw point cloud is of good quality and data passes Fundamental Vertical Accuracy specifications.

Data cover the entire area specified for this project.

Data is backed up to cloud storage.