Time Series of Structure-from-Motion Products - Multispectral Orthomosaics: Little Dauphin Island and Pelican Island, Alabama, September 2018 to April 2019

Aerial imagery acquired with a small unmanned aircraft system (sUAS), in conjunction with surveyed ground control points (GCP) visible in the imagery, can be processed with structure-from-motion (SfM) photogrammetry techniques to produce high-resolution orthomosaics, three-dimensional (3D) point clouds and digital elevation models (DEMs). This dataset, prepared by the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC), provides UAS survey data products consisting of multispectral (MS) orthomosaics produced from imagery collected at Little Dauphin Island and Pelican Island, Alabama, from September 2018 to April 2019 in order to develop integrated models linking geomorphology, habitat characteristics, and non-breeding shorebird species usage. Photogrammetry software was used to perform SfM processing on low-altitude digital aerial imagery acquired with a 3DR Solo UAS quadcopter equipped with a Ricoh GR II digital camera and MicaSense RedEdge 3 multispectral camera, using surveyed temporary targets (black and white, 4-square checked pattern) distributed uniformly throughout the UAS flight operations area as GCPs. The following SfM products are produced for each UAS survey over the northern half of Little Dauphin Island and all of Pelican Island: * georeferenced red-green-blue (RGB) orthomosaic image with 5-centimeter (cm) resolution * georeferenced MS orthomosaic image with 5-cm resolution * DEM with 5-cm horizontal resolution * 3D RGB-colored point cloud All horizontal data are provided in the Universal Transverse Mercator (UTM) projected coordinate system, Zone 16 North (16N), referenced to the North American Datum of 1983 (NAD83(2011)), and elevation is referenced to the North American Vertical Datum of 1988 (NAVD88), GEOID12B.