2023 USGS Topobathy Lidar: Santiam River, OR

Original Dataset Product: Classified LAS 1.4 files, formatted to 428 individual 1000m x 1000m tiles covering the Santiam River Topobathy project area.

Original Dataset Geographic Extent: This dataset and derived products encompass an area covering approximately 18,042 acres of Central Cascades in Oregon.

Original Dataset Description: The Santiam River Topobathy Lidar project called for the planning, acquisition, and processing of topobathy Lidar data collected to Quality Level 1 (QL1) standards for NIR, Quality Level 2b (QL2b) standards for green. Project specifications are based on the U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 2022, Revision A. The data was developed based on the NAD83 2011 horizontal datum and the NAVD88 Geoid 18 vertical datum. Data was projected in UTM Zone 10. Lidar data was delivered as calibrated and classified LAS 1.4 files. Non-Vegetated Vertical Accuracy (NVA) was assessed using 25 check points located on bare earth in clear, unobstructed areas. Submerged Topography accuracy was assessed using 433 check points collected as feasible in depths up to 1m. Vegetated Vertical Accuracy (VVA) was assessed using 11 check points in Tall Grass, Forest, and Shrub landcover types. Single swath nominal pulse spacing (NPS) was designed to be 0.35 at nadir. Aggregate Nominal Pulse Spacing (ANPS) was calculated to be 0.18 using all valid first return points. Derived products include: Intensity Imagery, Topbathymetric Digital Elevation Models (DEMs), Maximum Surface Height Rasters (DSMs), waters edge breaklines, and a bathymetric void shape.

Original Dataset Ground Condition: Ground condition was free of snow and acquisition occurred free of smoke, fog and cloud cover

This metadata supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). The NOAA Office for Coastal Management (OCM) downloaded the laz files from the USGS rockyweb site and processed the data to make it available for bulk and custom downloads from the NOAA Digital Coast Data Access Viewer (DAV).

The purpose of the lidar data was to produce a high accuracy 3D dataset that meets all necessary standards laid out by the 3D Elevation Program and the Santiam River Topobathy contract. The lidar point cloud data were used to create classified lidar LAS files, intensity images, topobathymetric DEMs, DEMs, highest hit DSMs, 3D breaklines of rivers and lakes within the study area, and a bathymetric void shape.

USGS Contract No. 140G0221D0012

CONTRACTOR: NV5 Geospatial

Ground Control Points were acquired and calibrated by NV5 Geospatial

All lidar data acquisition, calibration, and follow-on processing were completed by NV5 Geospatial.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 2022, Revision A",

"ldrsens" : "Riegl VQ-880GII-IR",

"ldrmaxnr" : "15",

"ldrnps" : "0.35",

"ldrdens" : "8",

"ldranps" : "0.18",

"ldradens" : "29.96",

"ldrfltht" : "400-500",

"ldrfltsp" : "145",

"ldrscana" : "42",

"ldrscanr" : "Uniform point spacing",

"ldrpulsr" : "150",

"ldrpulsd" : "3",

"ldrpulsw" : "0.9",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.3",

"ldrswatw" : "307-384",

"ldrswato" : "60-70",

"ldrgeoid" : "Geoid 18"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 2022, Revision A",

"ldrsens" : "Riegl VQ-880GII-IR",

"ldrmaxnr" : "15",

"ldrnps" : "0.35",

"ldrdens" : "8",

"ldranps" : "0.18",

"ldradens" : "29.96",

"ldrfltht" : "600-675",

"ldrfltsp" : "130",

"ldrscana" : "42",

"ldrscanr" : "Uniform point spacing",

"ldrpulsr" : "150",

"ldrpulsd" : "3",

"ldrpulsw" : "0.9",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.3",

"ldrswatw" : "461-518",

"ldrswato" : "60-70",

"ldrgeoid" : "Geoid 18"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 2022, Revision A",

"ldrsens" : "Riegl VQ-880GII-IR",

"ldrmaxnr" : "15",

"ldrnps" : "0.35",

"ldrdens" : "8",

"ldranps" : "0.18",

"ldradens" : "29.96",

"ldrfltht" : "900-1100",

"ldrfltsp" : "145",

"ldrscana" : "42",

"ldrscanr" : "Uniform point spacing",

"ldrpulsr" : "150",

"ldrpulsd" : "3",

"ldrpulsw" : "0.9",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.3",

"ldrswatw" : "691-845",

"ldrswato" : "60-70",

"ldrgeoid" : "Geoid 18"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 2022, Revision A",

"ldrsens" : "Riegl VQ-880G-Green",

"ldrmaxnr" : "15",

"ldrnps" : "0.50",

"ldrdens" : "4",

"ldranps" : "0.24",

"ldradens" : "17.72",

"ldrfltht" : "400-500",

"ldrfltsp" : "145",

"ldrscana" : "40",

"ldrscanr" : "80 lines per second",

"ldrpulsr" : "245",

"ldrpulsd" : "1.5",

"ldrpulsw" : "0.45",

"ldrwavel" : "532",

"ldrmpia" : "1",

"ldrbmdiv" : "0.7",

"ldrswatw" : "291-394",

"ldrswato" : "60-70",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid 18"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 2022, Revision A",

"ldrsens" : "Riegl VQ-880G-Green",

"ldrmaxnr" : "15",

"ldrnps" : "0.50",

"ldrdens" : "4",

"ldranps" : "0.24",

"ldradens" : "17.72",

"ldrfltht" : "600-675",

"ldrfltsp" : "130",

"ldrscana" : "40",

"ldrscanr" : "80 lines per second",

"ldrpulsr" : "245",

"ldrpulsd" : "1.5",

"ldrpulsw" : "0.45",

"ldrwavel" : "532",

"ldrmpia" : "1",

"ldrbmdiv" : "0.7",

"ldrswatw" : "437-491",

"ldrswato" : "60-70",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid 18"

},

"ldrinfo" : {

"ldrspec" : "U.S. Geological Survey National Geospatial Program Lidar Base Specification Version 2022, Revision A",

"ldrsens" : "Riegl VQ-880G-Green",

"ldrmaxnr" : "15",

"ldrnps" : "0.50",

"ldrdens" : "4",

"ldranps" : "0.24",

"ldradens" : "17.72",

"ldrfltht" : "900-1100",

"ldrfltsp" : "145",

"ldrscana" : "40",

"ldrscanr" : "80 lines per second",

"ldrpulsr" : "245",

"ldrpulsd" : "1.5",

"ldrpulsw" : "0.45",

"ldrwavel" : "532",

"ldrmpia" : "1",

"ldrbmdiv" : "0.7",

"ldrswatw" : "655-801",

"ldrswato" : "60-70",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid 18"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "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 were identified in these files using the standard LAS overlap bit.",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1W",

"clasitem" : "Edge clip"

},

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth ground"

},

"lasclass" : {

"clascode" : "7W",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18W",

"clasitem" : "High Noise"

},

"lasclass" : {

"clascode" : "20",

"clasitem" : "Ignored Ground Near Breaklines"

},

"lasclass" : {

"clascode" : "40",

"clasitem" : "Submerged Topography"

},

"lasclass" : {

"clascode" : "41",

"clasitem" : "Water Surface"

},

"lasclass" : {

"clascode" : "45",

"clasitem" : "Water Column"

}

}}

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.

LiDAR Mapping Suite 2.4, Applanix PosPac 7.1, Microstation CONNECT version, TerraScan Version 20, TerraModeler Version 20, TerraMatch Version 20, ESRI ArcGIS 10.3, Windows 10 Operating System

Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and inertial navigation system (INS) derived attitude error. The obtained RMSEr value is multiplied by a conversion factor of 1.7308 to yield the horizontal component of the National Standards for Spatial Data Accuracy (NSSDA) reporting standard where a theoretical point will fall within the obtained radius 95 percent of the time.

Based on a flying altitude of 500 meters, an IMU error of 0.005 decimal degrees, and a GNSS positional error of 0.023 meters, this project was produced to meet 0.141 meters horizontal accuracy at the 95% confidence level .

Some flightlines throughout the area of interest were flown at an AGL of 700 meters. With the same IMU and GNSS error as the AOIs above, but adjusting the altitude to 700 meters, the horizontal accuracy at the 95% confidence level was 0.193 meters.

The remaining flightlines were flown at an AGL of 1100 meters. With the same IMU and GNSS error as the AOIs above, but adjusting the altitude to 1100 meters, the horizontal accuracy at the 95% confidence level was 0.300 meters,

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class.

NV5 Determined Vertical Accuracy:

The NVA was tested with 25 independent check points located in open terrain and distributed throughout the project as feasible. These check points were not used in the calibration or post processing of the lidar point cloud data. Specifications for this project require that the NVA be 0.196 meters or better AccuracyZ at 95% confidence level.

For the Santiam River survey, 25 ground checkpoints were withheld from the calibration and post-processing of the lidar point cloud, with resulting non-vegetated vertical accuracy of 0.069 meters at the 95% confidence level (or 3.5 cm RMSE) as compared to the classified LAS, and 0.071 meters at the 95% confidence level (or 3.6 cm RMSE) against the bare earth DEM.

NV5 Geospatial 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 triangulated ground surface generated by the ground classified lidar points. For the Santiam River survey, 11 vegetated checkpoints were collected, with resulting vegetated vertical accuracy of 0.182 meters at the 95th percentile (or 9 cm RMSE) as compared to the classified LAS, and 0.182 meters at the 95th Percentile (or 8.5 cm RMSE) as compared to the bare earth DEM.

Bathymetric (submerged or along the water's edge) checkpoints were also collected in order to assess the submerged surface vertical accuracy. Assessment of 432 submerged bathymetric checkpoints resulted in a vertical accuracy of 0.097 meters at the 95% confidence interval (or 4.9 cm RMSE), while assessment of 276 wetted edge checkpoints resulted in a vertical accuracy of 0.104 meters at the 95% confidence interval (or 5.3 cm RMSE).

USGS Determined Vertical Accuracy:

Non-Vegetated Vertical Accuracy (NVA) = 3.38 cm RMSE

Vegetated Vertical Accuracy (VVA) = 16.82 cm at the 95th Percentile

Bathymetric Vertical Accuracy (BVA) = 9.74 cm at the 95th Percentile

These 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. Bathymetric void areas have been interpolated. A bathymetric void shape has been provided as a separate deliverable. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Classified LAS files were tested by NV5 for vertical accuracy. All data is seamless from one tile to the next, no gaps or no data areas.

Data is backed up to cloud storage.

The NOAA Office for Coastal Management (OCM) downloaded the laz files from the USGS rockyweb site and processed the data to make it available for bulk and custom downloads from the NOAA Digital Coast Data Access Viewer (DAV).