2013 OLC Lidar DEM: Turnbull National Wildlife Refuge, WA

Digital elevation model (DEM) derived from lidar covering the Turnbull project area encompassing 176,454 arcres in Lincoln and Spokane Counties in Washington. Data was collected and processed by WSI for the Oregon Lidar Consortium (OLC). NOAA Office for Coastal Management has taken the data and ingested into the Digital Coast Data Access Viewer after changing the projection and vertical datum. Data were collected between October 10, 2012 and July 23, 2013. Settings for lidar data capture produced and average resolution of at least eight pulses per square meter.

Original contact information:

Contact Name: Jacob Edwards

Contact Org: DOGAMI

Phone: 971-673-1557

Email: jacob.edwards@oregon.gov

Provide high resolution terrain elevation data.

Any conclusions drawn from the analysis of this information are not the responsibility of the Oregon Department of Geology and Mineral Industries (DOGAMI), FEMA, the Office for Coastal Management or its partners.

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer

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.

Horizontal accuracies were not specified in agreement since true horizontal accuracy is regarded as a product of the lidar ground foot print. Lidar is referenced to co-acquired GPS base station data that has accuracies far greater than the value of the lidar foot print. The ground footprint is equal to 1/3333rd of above ground flying height. Survey altitude for this acquisition was targeted at 900 meters yielding a ground foot print of 0.27 meters. This value exceeds the typical accuracy value of ground control used to reference the lidar data (<0.01m). Project specifications require the lidar foot print to fall between 0.15 and 0.40 meters.

A total of 3,412 measured GCP’s were obtained in the region and compared with the lidar elevation grids. The data delivered to DOGAMI was found to have a mean vertical offset of 0.009 meters (0.029feet) and an RMSE value of 0.042 meters (0.138 ft). Offset values ranged from -0.162 meters (‐0.531 feet) to 0.158 meters (0.518 feet)

LiDAR data has been collected and processed for all areas within the project study area.

Upon receipt from vendor (WSI), all LiDAR data was independently reviewed by staff from the Oregon Department of Geology and Mineral Industries (DOGAMI) to ensure project specifications were met. All data were inventoried for completeness and data were checked for quality, which included examining LiDAR data for errors associated with internal data consistency, model quality, and accuracy.