2005 USFS Lidar: Yaquina, OR

Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data for the United States Forest Service (USFS) in the Elk Creek watershed between July 13-15, 2005. The survey area is located inside the Siuslaw National Forest and encompasses all of Spout Creek (northern extent), Feagles Creek (southern extent), the confluence of these streams with Elk Creek (western extent), and up the headwaters of Elk Creek (eastern extent). The initial study area (~23,454 acres) was buffered by 200 meters, extending the contracted survey area to 26,385 acres.

Laser points were collected over the study area using an Optech ALTM 3100 LiDAR system set to acquire points at an average spacing of >8 points per square meter. The system also recorded individual return intensities (per laser return) that are used to create models that display surface reflectivity.

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.

The primary purpose of the lidar survey was to establish measurements of the bare earth surface, as well as top surface feature data for providing geometric inputs for modeling, other numerical modeling and economic related assessments.

Any conclusions drawn from the analysis of this information are not the responsibility of the USDA Forest Service, DOGAMI, NOAA, the Office for Coastal Management or its partners.

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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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

As described in Section 7.5 of the ASPRS Positional Accuracy Standards for Digital Geospatial Data, the horizontal errors in lidar data are largely a function of GNSS positional error, INS angular error, and flying altitude. Therefore, lidar data collected with GNSS error of 8cm and the IMU error of 0.00427 degrees at an altitude of 1,965m; the expected radial horizontal positional error will be RMSEr = 28.5cm.

Absolute Accuracy: This is the comparison of laser points to real time kinematic (RTK) ground level survey data. A total of 354 RTK GPS measurements were compared to ground laser points collected for comparison with the LiDAR point data. The deviation RMSE is 0.054 meters and the standard deviation is 0.053 meters, with a median (50th percentile) absolute deviation of 0.036 meters and a 95th percentile of 0.102 meters.

Internal Consistency: Internal consistency refers to the ability to place a laser point in the same location over multiple flight lines, GPS conditions and aircraft attitudes. The data were analyzed for internal consistency between opposing and orthogonal flight lines and passed divergence test requirements of less than 0.15 meters per any one overlapping flight line.

Laser Noise: For any given target, laser noise is the breadth of the data cloud per laser return (i.e., last, first, etc.). Lower intensity surfaces (roads, rooftops, still/calm water) will experience higher laser noise. The laser noise range for this mission varies between 0.040 - 0.070 meters

Data is backed up to tape and to cloud storage.

Watershed Sciences, Inc. (WS) collected Light Detection and Ranging (LiDAR) data for the United States Forest Service (USFS) in the Elk Creek watershed between July 13-15, 2005. NOAA OCM received the data and ingested it into the Digital Coast Data Access Viewer for distribution.