2018 USGS Lidar: Washington FEMA QL1

Product: Washington FEMA HQ Classified Lidar point cloud.

Geographic Extent: This dataset and derived products encompass the Washington FEMA HQ Lidar dataset, an area covering approximately 6519 acres of QL1 data in Washington State in Pend Orielle County in UTM Zone 11. A QL2 survey area was also part of this collection and covers approximately 3,450,211 acres encompassing portions of 5 counties: Whitman, Skamania, Cowlitz, Clark, and Klickitat. The QL2 survey area is not included in this data set because it was collected using QL2 criteria. A link to the metadata record for the QL2 survey area is provided in the Related Items field at the end of this metadata record.

Dataset Description: RAW flight line swaths were processed to create classified LAS 1.4 files projected in UTM Zone 11 and delineated in 1,000m x 1,000m tiles. (Please note the following tiles do not exist as no points fall within their boundaries due their small size and/or the fact they fall completely over water: 10TGR1465, 10TER6244) Each LAS file contains lidar point information, which has been calibrated, controlled, and classified. Additional derived products include intensity images, hydro-flattened DEMs, 3D breaklines of rivers and lakes, and bridges within the study area.

Ground Conditions: Ground condition was free of snow. Acquisition below aircraft free of smoke, fog and cloud cover. Ground Control Points were acquired and calibrated by Quantum Spatial, Inc.

The NOAA Office for Coastal Management (OCM) downloaded the:

1. Lidar point data from this USGS site:

ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/WA_FEMAHQ_2018_D18/WA_FEMAHQ_B1_QL1_2018/LAZ/

2. Breaklines from this USGS site:

ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/metadata/WA_FEMAHQ_2018_D18/WA_FEMAHQ_B1_QL1_2018/breaklines/

3. Reports and metadata from this USGS site:

ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/metadata/WA_FEMAHQ_2018_D18/WA_FEMAHQ_B1_QL2_2018/

The lidar point files were processed to the Data Access Viewer (DAV) and https. The total number of laz files downloaded and processed was 41.

The breakline data are available for download at the link provided in the URL section of this metadata record. Please note that these products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the Washington FEMA HQ Lidar contract. The raw lidar point cloud data were used to create classified lidar LAS files, intensity images, hydro-flattened DEMs, 3D breaklines of rivers and lakes, and bridges within the study area.

USGS Contract No. G16PC00016

CONTRACTOR: Quantum Spatial, Inc.

Ground Control Points were acquired and calibrated by Quantum Spatial, Inc.

All lidar data acquisition, calibration, and follow-on processing were completed by Quantum Spatial.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification, Version 1.3",

"ldrsens" : "Leica ALS80",

"ldrmaxnr" : "15",

"ldrnps" : "0.71",

"ldrdens" : "4",

"ldranps" : "0.35",

"ldradens" : "8",

"ldrfltht" : "1,800",

"ldrfltsp" : "110",

"ldrscana" : "30",

"ldrscanr" : "42",

"ldrpulsr" : "300",

"ldrpulsd" : "2.5",

"ldrpulsw" : "0.75",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "965",

"ldrswato" : "67",

"ldrgeoid" : "Geoid12B"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification, Version 1.3",

"ldrsens" : "Leica ALS80",

"ldrmaxnr" : "15",

"ldrnps" : "1.00",

"ldrdens" : "1",

"ldranps" : "0.70",

"ldradens" : "2",

"ldrfltht" : "2,300",

"ldrfltsp" : "125",

"ldrscana" : "30",

"ldrscanr" : "44",

"ldrpulsr" : "245",

"ldrpulsd" : "2.5",

"ldrpulsw" : "0.75",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1,233",

"ldrswato" : "25",

"ldrgeoid" : "Geoid12B"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification, Version 1.3",

"ldrsens" : "VQ-1560i",

"ldrmaxnr" : "15",

"ldrnps" : "1.00",

"ldrdens" : "1",

"ldranps" : "0.70",

"ldradens" : "2",

"ldrfltht" : "2,392",

"ldrfltsp" : "130",

"ldrscana" : "58.5",

"ldrscanr" : "68.1",

"ldrpulsr" : "700",

"ldrpulsd" : "3",

"ldrpulsw" : "0.90",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.18",

"ldrswatw" : "1,145",

"ldrswato" : "20",

"ldrgeoid" : "Geoid12B"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "0",

"clsnva" : "0",

"clsnvan" : "0",

"clsvva" : "0",

"clsvvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

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

"lasolap" : "Swath "overage" points are 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" : "NIR Water Surface"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "20",

"clasitem" : "Ignored Ground Near Breaklines"

}

}}

Any conclusions drawn from the analysis of this information are not the responsibility of Quantum Spatial, Inc., FEMA, USDA, USGS, 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 Inertial Explorer 8.7, Leica Cloudpro 1.2.4, Microstation Version 10.0, TerraScan Version 19, TerraModeler Version 19, TerraMatch Version 19, ESRI ArcGIS 10.3.1, LasMonkey 2.4.1 (Proprietary), Las Product Creator 3.1 (Proprietary), Windows 7 Operating System

For the Washington FEMA 3DEP 2018 survey (which includes the QL1 and QL2 survey areas), 128 ground check points were withheld from the calibration and post processing of the LiDAR point cloud, with resulting non-vegetated vertical accuracy of 0.119 meters as compared to unclassified LAS, and 0.119 meters as compared to the bare earth DEM, with 95% confidence. The NVA RMSE value is 6.1 cm.

QSI also assessed absolute accuracy using 4,387 ground control points. Although these points were used in the calibration and post-processing of the LiDAR point cloud, they still provide a good indication of the overall accuracy of the LiDAR dataset. The resulting non-vegetated vertical accuracy was also 0.119 meters as compared to unclassified LAS, and 0.119 meters as compared to the bare earth DEM, with 95% confidence. The NVA RMSE value is 6.1 cm.

QSI also assessed vertical accuracy using Vegetated Vertical Accuracy (VVA) reporting. VVA compares known ground check point data collected over vegetated surfaces using land class descriptions to the digital elevation model generated by the ground classified LiDAR points. For the Washington FEMA 3DEP 2018 survey, 98 vegetated check points were collected, with resulting vegetated vertical accuracy of 0.251 meters as compared to the bare earth DEM, evaluated at the 95th percentile. The VVA RMSE is 12.9 cm.

LAS files include all data points collected. No points have been removed or excluded. Shaded relief images have been visually inspected for data errors such as pits, border artifacts, and shifting. Lidar flight lines have been examined to ensure consistent elevation values across overlapping flight lines. The raw point cloud is of good quality and data passes Vertical Accuracy specifications.

Classified LAS files were tested by QSI for vertical accuracy. All data is seamless from one tile to the next, no gaps or no data areas.

Data is backed up to tape and to cloud storage.

Data collected by QSI, Inc. for USGS. The data were downloaded from the USGS rockyftp site and processed to make the data available for download from the NOAA OCM Data Access Viewer (DAV).