2018 OLC Lidar DEM: Morrow County, OR

No metadata record was provided for this data set. This record was created by the NOAA Office for Coastal Management (OCM) using information from the 3DEP Hydroflattened DEM metadata and making a minor adjustment to Process Step 3.

This GIS dataset contains Bare Earth (BE) raster grids depicting lidar-derived elevation data for Oregon Lidar Consortium (OLC) Morrow County project area. The BE raster dataset encompasses 801,116 acres within Morrow County County in Oregon. The nominal pulse density is eight pulses per square meter. The bare earth (BE) digital elevation model (DEM) raster grid cell size is 1 meter. The native projection was UTM Zones 10 and 11, 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 data set in partnership with the Oregon Department of Geology and Mineral Industries (DOGAMI).

In addition to these bare earth Digital Elevation Model (DEM) data, the lidar point data that these DEM data were created from, and the hydro breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record.

This data set 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.

Any conclusions drawn from the analysis of this information are not the responsibility of Quantum Spatial, Inc, 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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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.

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 66 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 63 checkpoints located in bare earth and urban (non-vegetated) areas; the 2. Vegetated Vertical Accuracy (VVA): VVA is reported for "forested", "shrub", and "tall grass" 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 63 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.

Tested 0.076 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 66 independent checkpoints located in Bare Earth and Urban land cover classes.

Tested 0.081 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 66 independent checkpoints located in the Bare Earth and Urban land cover categories.

Tested 0.152 meters VVA was calculated using 63 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.