2017 OLC Lidar: John Day, OR

Geographic Extent: OLC John Day 3DEP 2017 Buffered Project Area, covering approximately 702,005 acres.

Data set Description: The OLC John Day 3DEP 2017 LiDAR project called for the Planning, Acquisition, processing and derivative products of LIDAR data to be collected at a nominal pulse spacing (NPS) of 0.35 m. Project specifications are based on the U.S. Geological Survey National Geospatial Program LIDAR Base Specification, Version 1.2. The data were developed based on the UTM 11N projection; horizontal datum of NAD83 (2011), meters and vertical datum of NAVD88 Geoid 12B, meters. LiDAR data was delivered in RAW flight line swath format, processed to create Classified LAS 1.4 Files formatted to 0.075 USGS Quadrangle tiles, and Hydro-flattened Bare Earth DEMs tiled to 7.5 minute USGS quadrangles, and Bridge and Hydro Flattening Breaklines in ESRI File-Geodatabase format.

Ground Conditions: LiDAR was collected in 2017, 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 3,437 control points that were used to calibrate the LIDAR to known ground locations established throughout the OLC John Day 3DEP 2017 project area.

In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data and the breakline data are also available. These data are available for download at the links provided in the URL section of this metadata record.

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

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

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 the prime contractor.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program LIDAR Base Specification, Version 1.2",

"ldrsens" : "Leica ALS80",

"ldrmaxnr" : "unlimited",

"ldrnps" : "0.35 m",

"ldrdens" : "8 PPSM",

"ldranps" : "0.35 m",

"ldradens" : "8 PPSM",

"ldrfltht" : "1500 m",

"ldrfltsp" : "140 kts",

"ldrscana" : "30 degrees",

"ldrscanr" : "58.4 Hz",

"ldrpulsr" : "369.2 kHz",

"ldrpulsd" : "3 ns",

"ldrpulsw" : "0.25 m",

"ldrwavel" : "1064 nm",

"ldrmpia" : "1",

"ldrbmdiv" : "0.25 mrad",

"ldrswatw" : "804 m",

"ldrswato" : "60%",

"ldrcrs" : "North American Datum of 1983 (2011)",

"ldrgeoid" : "NAVD88 Geoid 12B"

},

"ldraccur" : {

"ldrchacc" : "0.05 m",

"rawnva" : "0.065 m",

"rawnvan" : "61"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "PF 6",

"laswheld" : "Withheld points are identified as aerial disturbance, low ground noise and atmospheric disturbances.",

"lasolap" : "Swath overage points are described as one degree to either side of overlapping swath boundaries.",

"lasintr" : "12 bits",

"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 Near Breakline"

},

"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 Quantum Spatial, Inc, USGS, the Oregon Lidar Consortium (OLC), DOGAMI, 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.

Inertial Explorer Version 8.7, Leica CloudPro Version 1.2.4, Microstation Version 8.0, TerraScan Version 17, TerraModeler Version 17, TerraMatch Version 17, ESRI ArcGIS 10.3.1, Windows 7 Operating System

LAS data from the OLC John Day 3DEP 2017 project was compared to independent survey control points to determine the NVA of the LAS Swath and of the Bare Earth DEM.

LAS Swath NonVegetated Vertical Accuracy (NVA) Tested 0.065 meter non-vegetated vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using 0.033 meter (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported against 61 NVA points using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the TIN. Swath points flagged as withheld were not included in the accuracy test.

Bare earth DEM Non-vegetated Vertical Accuracy (NVA) tested 0.074 meter non-vegetated vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using 0.038 meter (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported against 61 NVA points using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the DEM.

Vegetated Vertical Accuracy (VVA): The required accuracy of the VVA at the 95th percentile according to specification is 0.294 meter. The VVA tested 0.251 meter at the 95th percentile using National Digital Elevation Program (NDEP)/ASPRS Guidelines against the DEM using 45 VVA points.

Datasets contain complete coverage of tiles.

No points have been removed or excluded.

A visual qualitative assessment was performed to ensure data completeness.

There are no void areas or missing data. The raw point cloud is of good quality and data passes Nonvegetated Vertical Accuracy specifications.

Classified LAS files were tested by Quantum Spatial for both vertical and horizontal 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.