Point cloud, digital surface model (DSM), and orthoimagery derived from historical aerial imagery of the South Cow Mountain Recreational Area, Lake County, California, May 27, 1977

The USGS, in cooperation with the U.S. Bureau of Land Management (BLM), created a series of geospatial products of the South Cow Mountain Recreational Area, Lake County, California, using historic aerial imagery and structure-from-motion (SfM) photogrammetry methods. Products were generated from stereo historical aerial imagery acquired by the BLM in May of 1977. The aerial imagery were downloaded from the USGS Earth Resources Observation and Science (EROS) Data Center's USGS Single Aerial Frame Photo archive and a was created using USGS guidelines. Data were processed using SfM photogrammetry to generate a three-dimensional point cloud (.laz) that identifies pixels of an object from multiple images taken from various angles and calculates the x, y, and z coordinates of that object/pixel. The point cloud was processed to create a DSM (.tif) representing the continuous surface of the uppermost reflective surface (57.3 cm resolution). Finally, source images were stitched together based on shared pixels and orthogonally adjusted to the DSM to create a high resolution (approximately 18.3 cm) orthoimage (.tif) for the study area. This dataset includes a point cloud, digital surface model (DSM), and orthoimagery, as well as synthetic ground-control points (GCPs) and point clusters used to georeference the datasets. Separate metadata for each product are provided on the ScienceBase page for each child item.