2018 OLC Lidar DEM: Harney County, OR

This metadata record is for the Oregon Lidar Consortium (OLC) Harney 2018 area of interest (AOI) bare-earth, hydro-flattened DEM, which was produced in collaboration with the USGS 3DEP program. The defined project area (DPA) encompasses 128,891 acres, and the buffered project area (BPA) encompasses 133,051 acres. All data are in Harney County, Oregon. The nominal pulse density for the source lidar is eight pulses per square meter. The bare earth (BE) digital elevation model (DEM) raster grid cell size is 1 meter The native projection is Universal Transverse Mercator (UTM) Zone 11N, units are in meters. The native horizontal datum is NAD83(2011) and the native vertical datum is NAVD88 (Geoid 12B). Quantum Spatial Inc. collected the lidar and created this dataset in partnership with the Oregon Department of Geology and Mineral Industries (DoGAMI).

This dataset provides high resolution elevation data that is used to produce three-dimensional models of the earth surface for the purpose of managing natural resources and mapping natural hazards.

CONTRACTOR: Quantum Spatial, Inc.

All ground survey data, Lidar data acquisition, calibration, and follow-on processing were completed by the prime contractor, Quantum Spatial, Inc.

Users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, surveying, or site specific purposes. Users of this information should review or consult the primary data and information sources to ascertain the usability of the information. Acknowledgement of Oregon Department of Geology and Industries (DoGAMI) would be appreciated for products derived from these data.

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 or 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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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 Version 8.0, TerraScan Version 16, TerraModeler Version 16, TerraMatch Version 16, ESRI ArcGIS 10.3.1, Windows 7 Operating System

The project specifications require that only Non-Vegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The required accuracy (ACCz) is: 19.6 cm at a 95% confidence level, derived according to NSSDA (i.e., based on RMSE of 10 cm in the "bare earth" and "urban" land cover classes). The Raw Swath NVA was tested with 46 checkpoints located in bare earth and urban (non-vegetated) areas. These checkpoints were not used in the calibration or post processing of the lidar point cloud data. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control points. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy at 95% 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.

The project specifications require the accuracy (ACCz) of the derived DEM be calculated and reported in two ways: 1. The required NVA is: 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 10 cm in the "bare earth" and "urban" land cover classes. This is a required accuracy. The Bare Earth DEM NVA was tested with 46 checkpoints located in bare earth and urban (non-vegetated) areas; the 2. Vegetated Vertical Accuracy (VVA): VVA is be reported for "forested", "brushland/trees", and "tall weeds/crops" land cover classes. The target VVA is: 29.4 cm at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for Lidar Data, i.e., based on the 95th percentile error in all vegetated land cover classes combined. This is a target accuracy. The VVA was tested with 10 checkpoints located in vegetated areas. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy at 95% 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.Quantitative value: 0.063 0.070 0.092, Test that produced the value:

Tested 0.063 meters NVA at a 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The NVA of the raw lidar point cloud swath files was calculated against TINs derived from the final calibrated and controlled swath data using 46 independent checkpoints located in Bare Earth and Urban land cover classes. (RMSE = 3.2 cm).

Tested 0.070 meters NVA at a 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The NVA of the DEM was calculated using 46 independent checkpoints located in the Bare Earth and Urban land cover categories.

Tested 0.092 meters VVA was calculated using 10 checkpoints located in vegetated land cover categories at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for Lidar Data. Tested against the DEM.

A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist.

Data covers the entire area specified for this project.

Data is backed up to tape and to cloud storage.