Structure from Motion 3 m DEM of Vicksburg, MS created from 1938 aerial imagery

The dataset is a 3 m spatial resolution Digital Elevation Model (DEM) representing terrain heights in northern Vicksburg, MS and Vicksburg National Military Park in 1938. The DEM was created using structure from motion-aided (SfM-aided) photogrammetry techniques in Agisoft Metashape (v 2.1.1). The aerial images were acquired on June 30, 1938 by Pan American Aerial Surveys for the U.S. Department of Agriculture at approximately 1:20,000 scale by a Fairchild K-10 or similar aerial camera with 5in x 7in frame. The images, archived together with other unrelated aerial imaging projects on film rolls, were accessed at the National Archive in College Park, MD and scanned to digital using an Epson scanner at 2400 dots per inch with 16-bit radiometric resolution. In total, 14 frames were scanned, ranging from AVM-3-13 to AVM-3-23A and AVM-2-129 to AVM-2-132. Of these 14 frames, only 4 (AVM-3-19 - AVM-3-122) were found to be useable for SfM-aided DEM generation. Ground reference was established through 83 ground control points (GCPs), with horizontal coordinates acquired from the 2017 high-resolution orthoimagery (HRO) of Warren County, Mississippi, and vertical elevations acquired from a 1m DEM created from 2020 lidar. The dense point cloud produced by the SfM-aided photogrammetric process was classified to identify points lying on or near the ground; these ground points were then used to interpolate a DEM with a spatial resolution of 81.6 cm. Errors and noise in the DEM surface were reduced through filtering and then resampled to 3 m using bilinear interpolation.