2015 USGS Lidar: Lincoln County, WI

Geographic Extent: Lincoln County, WI Area of Interest, covering approximately 946 square miles.

Dataset Description: The Lincoln County, WI lidar project called for the Planning, Acquisition, processing and derivative products of LIDAR data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LIDAR Specification, Version 1.2. The data was developed based on a horizontal projection/datum of Wisconsin County Coordinate System - Lincoln County, NAD83 (2011), US Survey Feet and vertical datum of NAVD1988 (GEOID12A), US Survey Feet. Lidar data was delivered in RAW flight line swath format, processed to create Classified LAS 1.2 Files formatted to 1,396 individual 4500 ft x 4500 ft tiles. Corresponding 5-foot gridded Hydro Flattened Raster DEM Files tiles were created using the same 4500 ft x 4500 ft schema. Hydro-Flattening Breaklines were produced in ESRI shapefile format. The hydroflattened bare earth surface DEM was used to create 2-foot contours in ESRI file geodatabase format.

Ground Conditions: Lidar collection began in Spring 2015, 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, Quantum Spatial established a total of 121 control points (22 control calibration points and 99 QC checkpoints). These were used to calibrate the LIDAR to known ground locations established throughout the project area.

Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Breaklines and Raster DEMs.

The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 5 foot cell size.

These raw lidar point cloud data were used to create classified lidar LAS files, 3D breaklines, hydro-flattened DEMs, and contours as necessary.

USGS Contract: G10PC00026 Task Order Number: G15PD00294

CONTRACTOR: Quantum Spatial

Lidar data were acquired and calibrated by Quantum Spatial.

All follow-on processing was completed by the prime contractor.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS70_SN7161",

"ldrmaxnr" : "4",

"ldrnps" : "0.65",

"ldrdens" : "2.37",

"ldranps" : "0.65",

"ldradens" : "2.37",

"ldrfltht" : "2436",

"ldrfltsp" : "140",

"ldrscana" : "20.0",

"ldrscanr" : "37.7",

"ldrpulsr" : "261.00",

"ldrpulsd" : "4",

"ldrpulsw" : "0.48",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1528.67",

"ldrswato" : "10.32",

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

},

"ldrinfo7178" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS70_SN7178",

"ldrmaxnr" : "4",

"ldrnps" : "0.65",

"ldrdens" : "2.19",

"ldranps" : "0.65",

"ldradens" : "2.19",

"ldrfltht" : "2436",

"ldrfltsp" : "140",

"ldrscana" : "20.0",

"ldrscanr" : "37.7",

"ldrpulsr" : "261.00",

"ldrpulsd" : "4",

"ldrpulsw" : "0.48",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1528.67",

"ldrswato" : "10.32",

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

},

"ldrinfo7234" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "SN7234_HP_FOV60",

"ldrmaxnr" : "4",

"ldrnps" : "1.41",

"ldrdens" : "0.46",

"ldranps" : "1.41",

"ldradens" : "0.46",

"ldrfltht" : "2436",

"ldrfltsp" : "140",

"ldrscana" : "20.0",

"ldrscanr" : "37.7",

"ldrpulsr" : "55.30",

"ldrpulsd" : "4",

"ldrpulsw" : "0.48",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1528.67",

"ldrswato" : "10.32",

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

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.086",

"rawnvan" : "55",

"clsnva" : "0.088",

"clsnvan" : "54",

"clsvva" : "0.258",

"clsvvan" : "45"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS Withheld 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" : "7",

"clasitem" : "Low noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored Ground"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High noise"

}

}}

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.

MicroStation Version 8; TerraScan Version 15; TerraModeler Version 15; GeoCue Version 2014.1.21.1; ESRI ArcGIS 10.2; Global Mapper 16; Leica Cloud Pro 1.2; Windows 7 Operating System \\psihq_nx3200\Projects\26256_LincolnCoWisonsin\ 54.3 GB and \\Matrix\LIDAR\26256_Lincoln_Co\ 780 GB

The specifications require that only Nonvegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The vertical accuracy was tested with 55 independent survey located in open terrain. These check points were not used in the calibration or post processing of the lidar point cloud data. The survey check points were distributed throughout the project. Specifications for this project require that the NVA be 19.6 cm or better AccuracyZ at 95 percent confidence level.Quantitative value: 0.086, Test that produced the value: The NVA was tested using 55 independent surveys located in open terrain. The survey check points were distributed throughout the project area. The 55 independent check points were surveyed using the closed level loop technique. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control. The RMSE was computed to be 0.148 survey feet (0.045 meters). AccuracyZ has been tested to meet 19.6 cm NVA at 95 percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

These raw 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 Nonvegetated Vertical Accuracy specifications.

Data cover the entire area specified for this project.

Data is backed up to cloud storage.