2015 NRCS Lidar: Pike and Scott Counties, IL

Geographic Extent: Pike and Scott Counties in western Illinois, covering approximately 1,100 total square miles.

Dataset Description of Original Data: The Pike and Scott Counties 2015 LiDAR project called for the planning, acquisition, processing and derivative products of LIDAR data to be collected at an aggregate nominal pulse spacing (NPS) of 0.5 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 NAD83 (2011), State Plane Coordinate System Illinois West Zone, US survey feet and vertical datum of NAVD1988 (Geoid 12B), US survey feet. LiDAR data was delivered in RAW flight line swath format, processed to create Classified LAS 1.4 Files formatted to 7,998 individual 2,000-foot x 2,000-foot tiles. Corresponding 2-foot intensity image and 2-foot bare earth DEM tiles were created with the same 2,000-foot x 2,000-foot tile schema. Tiles names follow the US National Grid naming schema. Continuous breaklines were produced in Esri shapefile format. A mosaic of the 2-foot bare earth raster DEM tiles was also produced in Esri grid format.

Ground Conditions: LiDAR was collected in winter of 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 42 calibration control points in order to calibrate the LIDAR to known ground locations established throughout the project area. The accuracy of the data was checked with 58 NVA points and 47 VVA points (105 total QC checkpoints).

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.

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 Model (DEM) with a 2-foot cell size. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2-foot cell size.

USGS Contract: G10PC00026 Task Order Number: G15PD01036

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" : "Optech Orion H300",

"ldrmaxnr" : "5",

"ldrnps" : "0.49",

"ldrdens" : "4.22",

"ldranps" : "0.49",

"ldradens" : "4.22",

"ldrfltht" : "1400",

"ldrfltsp" : "130",

"ldrscana" : "29",

"ldrscanr" : "68.0",

"ldrpulsr" : "275",

"ldrpulsd" : "4",

"ldrpulsw" : "0.41",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.25",

"ldrswatw" : "724.13",

"ldrswato" : "30",

"ldrgeoid" : "g2012bu0.bin"

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.076",

"rawnvan" : "58",

"clsnva" : "0.077",

"clsnvan" : "58",

"clsvva" : "0.144",

"clsvvan" : "47"

},

"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" : "3",

"clasitem" : "Low Vegetation"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "Medium Vegetation"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "High Vegetation"

},

"lasclass" : {

"clascode" : "6",

"clasitem" : "Man-Made Structures"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "In-land 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 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.

MicroStation Version 8; TerraScan Version 15; TerraModeler Version 15; GeoCue Version 2014.1.21.1; Esri ArcGIS 10.3; Global Mapper 16; Leica Cloud Pro 1.2; Windows 10 Operating System

\\PSIHQ_NX3200\Projects\Projects\26869_Pike_Scott_County_USGS 897 GB and \\matrix\matrix\LIDAR\26869_NRCS_Pike_Scott_Counties 8.95 TB

The specifications require that only raw Nonvegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The raw NVA was tested with 58 independent survey points distributed throughout the project area and located in open terrain. These checkpoints were not used in the calibration or post-processing of the lidar point cloud data. Specifications for this project require that the raw NVA be 19.6 cm or better AccuracyZ at 95 percent confidence level.

The raw NVA was tested using 58 independent survey points located in open terrain. The surveyed checkpoints were distributed throughout the project area and surveyed using GNSS procedures and methodologies that provide reliable and consistent results to meet the project's accuracy requirements. Please see the "Survey Accuracy Requirements" and "Field Methodology" sections in the Survey Report for more information. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the unclassified lidar surface were then compared to the elevation values of the surveyed control. The RMSEz was computed to be 0.039 meters (0.126 feet) and AccuracyZ to be 0.076 meters (0.248 feet). This meets the required AccuracyZ value of 19.6 cm raw 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.

The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tiles (EPT) 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.