2017 FEMA Lidar: Waushara County, WI

Geographic Extent: Waushara County, Wisconsin covering approximately 647 square miles.

Dataset Description of Original Data: Waushara County, Wisconsin 2017 QL2 LiDAR project required planning and acquisition of LiDAR data collected with a point density of 2 pulses per meter with at a nominal point spacing of 0.71 meters. Project specifications were 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, Wisconsin South, US survey feet and vertical datum of NAVD1988 (GEOID12B), US survey feet. LiDAR data was delivered as 35 calibrated and controlled RAW flight line swaths, processed to create 760 Classified LAS 1.4 files formatted to individual 5000 x 5000-foot tiles, corresponding 2.0-ft hydro-flattened bare-earth DEMs tiled to the same 5000 x 5000-foot schema in ERDAS .IMG format, and hydro-flattened feature breaklines in Esri polygonZ shapefile and polygonZ file geodatabase feature class format.

Ground Conditions: LiDAR was collected in 3 lifts spanning 2 days in the Fall of 2017, with no snow, water at normal levels without unusual inundation, and leaf off conditions. In order to post process the LiDAR data to meet task order specifications, 20 surveyed control points were used to calibrate the LIDAR to known ground locations established throughout the project area. The accuracy of the data was checked with a total of 70 surveyed QC check points.

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 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-ft cell size. The data will be used by FEMA for flood-plain mapping. These raw lidar point cloud data were used to create classified lidar LAS files, 3D breaklines, and hydro-flattened DEMs as necessary.

FEMA Contract No. HSFE60-15-D-0005

FEMA Task Order No. HSFE05-17-J-0005

CONTRACTOR: STARR II

SUBCONTRACTOR: Continental Mapping Consultants

Continental Mapping Consultants worked with CompassData to acquire and calibrate ground control points. All Lidar data acquisition, calibration, and follow-on processing were completed by Continental Mapping Consultants.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

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

"ldrsens" : "Leica ALS70",

"ldrmaxnr" : "5",

"ldrnps" : "0.684",

"ldrdens" : "2.14",

"ldranps" : "0.586",

"ldradens" : "2.91",

"ldrfltht" : "2200",

"ldrfltsp" : "160",

"ldrscana" : "38",

"ldrscanr" : "49.2",

"ldrpulsr" : "135.3",

"ldrpulsd" : "N/A",

"ldrpulsw" : "1.0",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1300",

"ldrswato" : "20",

"ldrgeoid" : "g2012bu3.bin"

},

"ldraccur" : {

"ldrchacc" : "0.1",

"rawnva" : "0.094",

"rawnvan" : "40",

"clsnva" : "0.080",

"clsnvan" : "40",

"clsvva" : "0.039",

"clsvvan" : "30"

},

"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-bit",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Undetermined/Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored ground"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridges"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

}

}}

All rights to produced data belong to FEMA.

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.

Environment as of Metadata Creation: Microsoft Windows 7 Professional; Esri ArcGIS 10.2.2; Microstation CONNECT Edition Update 2 (version 10.02.00.39); TerraScan (version 018.008)

The specifications require that only Non-vegetated Vertical Accuracy (NVA) can be computed for raw lidar point cloud swath files. The vertical accuracy was tested with 40 independent surveys 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.

The NVA was tested using 40 independent surveys located in open terrain. The survey check points were distributed throughout the project. The 40 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 unclassified lidar surface were then compared to the elevation values of the surveyed control. The RMSE was computed to be 0.048 meters and AccuracyZ to be 0.094 meters. AccuracyZ has been tested to meet the required AccuracyZ value of 19.6 cm for Non-Vegetated Vertical Accuracy at 95 Percent confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines.

These classified 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 classified point cloud is of good quality and data passes Non-vegetated Vertical Accuracy (NVA) specifications. Datasets contain complete coverage of tiles over the project area.

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.