2013 OLC Lidar DEM: West Ochoco, OR

The dataset encompasses 474 square miles in the Ochoco National Forest of Oregon, including portions of Crook, Jefferson, and Wheeler Counties, Oregon. The highest hit digital surface models (DSM) represent the earth's surface with all vegetation and human-made structures included. The DSMs represent the earth's surface with all vegetation and human-made structures included. The highest hit DSMs were derived from lidar data using the highest hit method. The bare earth digital elevation model (DEM) represents the earth's surface with all vegetation and human-made structures removed. The bare earth DEMs were derived from lidar data using TIN processing of the ground point returns. The DSM and DEM grid cell size is 3 international feet. The elevation units are in international feet. Some elevation values have been interpolated across areas in the models where there is no elevation data (e.g. over water, over dense vegetation). Watershed Sciences, Inc.

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

xyz location information for objects in the area

This dataset was contracted by Oregon Department of Geology and Mineral Industries (DOGAMI). Information regarding the use of this dataset should be directed to the owner.

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 custom downloads

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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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

Vertical accuracy compares the delivered bare-earth digital elevation models (DEMS) with independent ground check points (GCPs) collected by DOGAMI staff. These variations in elevation values were used to produce a mean vertical error and vertical root mean square error (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) and the maximum vertical RSME to not exceed 0.0925 meters (0.303 feet). A total of 4,400 independently measured GCPs were obtained in the OLC Ochoco West project area. The data delivered to DOGAMI was found to have a mean vertical offset of 0.005 meters (0.017 feet) and an RMSE value of 0.047 meters (0.154 feet).

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DOGAMI examines all data associated with this delivery to ensure that all required data products are present and function correctly. Quality control review is conducted on every data file delivered to DOGAMI. Lidar ASCII Standard (LAS) point files have been loaded into TerraSolid and ArcGIS to ensure complete and correct lidar data coverage and file integrity. Raster and vector files have been viewed in ArcMap and cross referenced with the delivery area to ensure proper coverage, extent and integrity. Metadata content is reviewed by using a visual check as well as analysis by the USGS Geospatial Metadata validation service.

Consistency Analysis: Consistency refers to lidar elevation differences between overlapping flight lines. Consistency errors are created by poor lidar system calibration settings associated with sensor platform mounting. Errors in consistency manifest as vertical offsets between individual flight lines. Lidar flight lines have been examined to ensure that there was at least 60% sidelap, there are no gaps between flightlines, and the vertical offsets between flight line must be less than 0.15m (0.49 feet).

Consistency offsets were measured using the 'Find Match' tool within the TerraMatch software toolset. This tool uses aircraft trajectory information linked to the lidar point cloud to quantify flight line-to-flight line offsets. To quantify the magnitude of this error 2,278 delivered data tiles were examined for vertical offset between flight lines. Data tiles with less than 1000 points were not used in analysis. Selection of tiles aimed to evenly sample the delivered spatial extent of data. Each tile measured 750 x 750 meters in size. Within each tile, we selected all ground classified points from each flight line, and compared the elevations of the points in each set of overlapping lines. The average number of points used for flight line comparison was 16,314,783 per tile. Error measurements were calculated by differencing the nearest point from an adjacent flight line within 1 meter in the horizontal plane and 0.2 meters in the vertical plane. Each flight line was compared to adjacent flight lines, and the average magnitude of vertical error was calculated. A total of 401 flight lines were sampled and compared for consistency. Results of the consistency analysis found the average flight line offset to be 0.03 meters with a maximum error of 0.039. Distribution of error showed 100% of all error was less than 0.04m. These results show that all data are within tolerances of data consistency according to contract agreement.

Data is backed up to tape and to cloud storage.

Watershed Sciences Inc. has collected Light Detection and Ranging (LIDAR) data in the Ochoco West Study Area for the Oregon Department of Geology and Mineral Industries (DOGAMI).

NOAA OCM has taken the data and ingested it into the Digital Coast Data Access Viewer for distribution.