2022 - 2023 DOGAMI/OLC Lidar DEM: Jackson County, OR

Original Product: This GIS dataset contains hydro-flattened Bare Earth (BE) raster models depicting lidar-derived elevation data for the 2023 OLC Jackson County Lidar project area. Raster models were delivered by AOI mosaic in addition to the 3000ft tiles.

Original Geographic Extent: Jackson County, Oregon, covering approximately 506,952 acres.

Original Dataset Description: The OLC Jackson County 2023 Lidar project called for the planning, acquisition, processing and production of derivative products of the lidar data and was to be collected at a nominal pulse spacing (NPS) of 8 ppsm - 0.350 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Lidar Base Specification, Version 2022 rev. A. The native projection is Oregon Lambert Conic Conformal, units are in International feet. The native horizontal datum is NAD83(2011); the native vertical datum is NAVD88; (Geoid 18). Bare earth DEMs were derived from the classified lidar data and delivered within a 3000 ft x 3000 ft tiling schema.

Ground Conditions: Lidar was collected between November 14th, 2002 - November 22nd, 2002 and June 28th, 2023 - June 30th, 2023 while no snow was on the ground and the area was free of cloud cover.

This data was provided to the NOAA Office for Coastal Management (OCM) by DOGAMI (Oregon Department of Geology and Mineral Industries), for the purpose of making the data publicly available for custom and bulk downloads from the NOAA Digital Coast Data Access Viewer.

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: NV5 Geospatial

All ground survey data, Lidar data acquisition, calibration, and follow-on processing were completed by the prime contractor, NV5 Geospatial. Hydro-flattening of rivers and water bodies was completed by DOGAMI.

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be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions.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. Acknowledgment 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.

To the extent possible under law, the U.S. Government has waived all copyright and related or neighboring rights to this dataset.

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.

Bayes StripAlign v2.2, Applanix PosPac 8.7, Microstation Connect, TerraScan Version 19, TerraModeler Version 19, TerraMatch Version 19, ESRI ArcGIS 10.8.1, LAS Product Creator (NV5 Proprietary), LasMonkey (NV5 Proprietary), Windows 10 Operating System

Lidar horizontal accuracy is a function of Global Navigation Satellite System (GNSS) derived positional error, flying altitude, and 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 2500 meters, an IMU error of 0.002 decimal degrees, and a GNSS positional error of 0.023 meters, this project was produced to meet 0.896 feet (0.273 meters) horizontal accuracy at the 95% confidence level.

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class. The specifications require that classified Non-vegetated Vertical Accuracy (NVA) be computed from the derived DEMs. The NVA was tested with 54 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. Vegetated Vertical Accuracy (VVA) is also to be computed from the derived DEMS. The VVA was tested with 46 check points in Tall Grass, Forest, and Shrub land cover types. These check points were also withheld from the calibration and post processing of the lidar point cloud data and distributed throughout the project area as feasible. Specifications for this project require that the VVA be 0.300 meters or better AccuracyZ at the 95th percentile.

The 54 independent NVA check points were surveyed using the closed level loop technique. Elevations of the derived bare earth DEMs were compared to the elevation values of the surveyed NVA check points. The RMSE was computed to be 0.075 feet (0.023 meters) resulting in an AccuracyZ of 0.146 feet (0.045 meters) at the 95% confidence level. NVA AccuracyZ has been tested and meets the required 0.196 meter NVA at 95% confidence level using (RMSEz * 1.9600) for the derived bare earth DEMs as defined by the National Standards for Spatial Data Accuracy (NSSDA) and herein reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

The 46 independent VVA check points were surveyed using the closed level loop technique. Elevations of the derived bare earth DEMs were compared to the elevation values of the surveyed VVA check points. The RMSE was computed to be 0.320 feet (0.098 meters) resulting in an AccuracyZ of 0.531 feet (0.162 meters) at the 95% confidence level. VVA AccuracyZ has been tested and meets the required 0.300 meter NVA at 95% confidence level using (RMSEz * 1.9600) for the derived bare earth DEMs as defined by the National Standards for Spatial Data Accuracy (NSSDA) and herein reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

DEM files were tested by NV5 Geospatial 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.

This data was provided to the NOAA Office for Coastal Management (OCM) by the DOGAMI (Oregon Department of Geology and Mineral Industries), for the purpose of making the data publicly available for custom and bulk downloads from the NOAA Digital Coast Data Access Viewer.