2011 - 2012 OLC Lidar DEM: Union Baker, OR

No metadata record for this data set was provided to the NOAA Office for Coastal Management (OCM). This record was created with information from the data report. A link to the data report is provided in the URL section of this metadata record.

WSI collected Light Detection and Ranging (LiDAR) data of the Union Baker Study Area for the Oregon Department of Geology and Mineral Industries (DOGAMI). The total Area of Interest (AOI) and the total area flown (TAF) covers 379,002 acres and 390,797 acres respectively. The TAF acreage is greater than the original AOI acreage due to buffering and flight planning optimization. Union Baker data were delivered in: OGIC (HARN): Projection: Oregon Statewide Lambert Conformal Conic; horizontal and vertical datum: NAD83 (HARN)/NAVD88 (Geoid03); units: International Feet; grid resolution: 3 ft. The acquisition dates were:

Delivery 1: Dec 8 -12, 2011

Delivery 2: May 14 - July 3, 2012

This dataset provides high resolution terrain elevation and land cover elevation data in the Union Baker study area.

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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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

DOGAMI Horizontal Accuracy for Delivery 1 and 2:

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 within 0.15 and 0.40 meters. DOGAMI was able to test the horizontal accuracy of survey monuments used to reference the lidar data while conducting vertical control measurements. For internal purposes only, the XY coordinates of survey monuments surveyed by DOGAMI were compared to the survey monuments provided by the vender and in almost every case, the reported results were consistent with those obtained by DOGAMI staff.

Watershed Sciences Vertical Accuracy:

FVA accuracy reporting is designed to meet guidelines presented in the National Standard for Spatial Data Accuracy (NSSDA) (FGDC, 1998). FVA compares known RTK ground survey points to the closest laser point. FVA uses ground control points in open areas where the LiDAR system has a “very high probability” that the sensor will measure the ground surface and is evaluated at the 95% percentile of RMSEZ. For the Union Baker Study Area, 4,193 RTK points were collected.

For this project, no independent survey data were collected, nor were reserved points collected for testing. As such, vertical accuracy statistics are reported as “Compiled to Meet,” in accordance with the ASPRS Guidelines for Vertical Accuracy Reporting for LiDAR Data V1.0 (ASPRS, 2004). Fundamental Vertical accuracy for the entire study area is 9 cm (4 cm RMSE).

DOGAMI Vertical Accuracy for Delivery 1:

Vertical accuracy analysis consisted of differencing control data and the delivered lidar Digital Elevation Models (DEM) to expose offsets. These offsets were used to produce a mean vertical error and vertical RMSE value for the entire delivered data set. Project specifications list the maximum acceptable mean vertical offset to be 0.20 meters (0.65 feet). A total of 159 measured GCP’s were obtained in the Delivery 1 region and compared

with the lidar elevation grids. The data delivered to DOGAMI was found to have a mean vertical offset of -0.038 meters (-0.126 feet) and an RMSE value of 0.053 meters (0.173 ft). Offset values ranged from -0.103 to 0.059 meters.

DOGAMI Vertical Accuracy for Delivery 2:

Vertical accuracy analysis consisted of differencing control data and the delivered lidar Digital Elevation Models (DEM) to expose offsets. These offsets were used to produce a mean vertical error and vertical RMSE value for the entire delivered data set. Project specifications list the maximum acceptable mean vertical offset to be 0.20 meters (0.65 feet). A total of 8025 measured GCP’s were obtained in the Delivery 2 region and compared with the lidar elevation grids. The data delivered to DOGAMI was found to have a mean vertical offset of -0.050 meters (-0.164 feet) and an RMSE value of 0.070 meters (0.231 ft). Offset values ranged from -0.288 to 0.176 meters.

Data is backed up to tape and to cloud storage.

Watershed Sciences, LLC collected Light Detection and Ranging (LIDAR) data in the Union Baker project area for DOGAMI. NOAA OCM received the data and ingested it into the Digital Coast Data Access Viewer for distribution.