Watershed Sciences, Quantum Spatial, Inc. (QSI), and NV5 have all collected Light Detection and Ranging (lidar) data from HJ Andrews and the Willamette National Forest (WNF) over a series of years (2008, 2011, 2014, 2016, 2020, and 2021). Flight acquisition details, including sensor, elevation, point density, accuracy, and area differ, sometimes substantially. In particular, coordinate systems differ among acquisitions as do workflows for generating data products, like 1-m rasters of ground height, presenting a challenge to time-series analysis. To allow for time-series analysis for lidar data products, we developed a common workflow for processing lidar point clouds to generate temporally consistent geospatial products. We reprojected all point clouds (.las files) to UTM 10. We then generated rasters for (1) digital terrain, digital surface, and canopy height models at 1-m resolution (m) and (2) derivative topographic (slope, aspect, hillshade) and vegetation (crownshade, 95th percentile height, standard deviation in height, canopy cover) at 5- and 25-m resolutions. Shapefiles were also generated for (1) the extent of the processed data and (2) 10-m contour lines.
David M. Bell
The purpose of this work was to generate standard geospatial products from differing lidar acquisitions for researchers to use to represent state and change of the landscape topography and vegetation. The data for individual acquisitions was collected to provide a highly accurate and comprehensive base layer of elevation data and vegetation cover for differing areas of interest that overlap portions of the H. J. Andrews Experimental Forest. The purpose of the data is to provide users with a very accurate view of the topography and vegetation of the study area. The data are suitable for creating visualizations, deriving watershed boundaries, creating stream networks, identifying structures such as roads and water features, vegetation modeling and mapping, and for identifying landslides and geological features.