Structure-from-Motion Products - Prime Hook National Wildlife Refuge, Delaware - Digital Elevation Model: 2020

Aerial imagery was collected by a contractor using a fixed wing aircraft fitted with Post-Processing Kinematic (PPK) GPS, was processed using Structure-from-Motion (SfM) photogrammetry techniques to produce high-resolution orthomosaic images, three-dimensional (3D) point clouds and digital elevation models (DEMs). Surveyed Ground Control Points (GCPs) visible in the imagery are used to supplement the calculated elevation and PPK position data. This dataset, produced by the U.S. Geological Survey (USGS) MD-DE-DC Water Science Center, consists of a point cloud generated from the survey of Prime Hook National Wildlife Refuges in Delaware in order to observe annual changes. Structure-from-Motion software, Agisoft Metashape, was used to perform processing on low-altitude digital aerial imagery acquired by a contractor utilizing a fixed wing aircraft. The aircraft has been modified with a camera port fitted with a Sony A7R camera and equipped with a custom Post-Processing Kinematic GPS device. The surveys were conducted using temporary targets (black and white, 4-square checkered pattern), and pre-existing points (road markings) distributed throughout the flight operations area as GCPs. This dataset was produced using the 4D method of Structure-from-Motion, combining multiple years of images and GCPs into a single project to assist in alignment. Each year's chunk was then checked, cleaned, and exported individually. All horizontal data are referenced to the North American Datum of 1983 (NAD83 (2011)) UTM zone 18N, and elevation is referenced to the North American Vertical Datum of 1988 (NAVD88) in meters, GEOID12B.

                                            [
  "010:12"
]
                                        

                                            {
  "fn": "Jaymes P. Swain",
  "@type": "vcard:Contact",
  "hasEmail": "mailto:jswain@usgs.gov"
}
                                        

                                            [
  {
    "@type": "dcat:Distribution",
    "title": "Digital Data",
    "format": "XML",
    "accessURL": "https://doi.org/10.5066/P9BCCLZE",
    "mediaType": "application/http",
    "description": "Landing page for access to the data"
  },
  {
    "@type": "dcat:Distribution",
    "title": "Original Metadata",
    "format": "XML",
    "mediaType": "text/xml",
    "description": "The metadata original format",
    "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.62962738d34ec53d276ba93d.xml"
  }
]
                                        

                                            [
  "Delaware",
  "Fowler Beach",
  "Prime Hook National Wildlife Refuge",
  "U.S. Geological Survey",
  "USGS",
  "USGS:62962738d34ec53d276ba93d",
  "coastal processes",
  "geoscientificInformation",
  "geospatial datasets",
  "imageryBaseMapsEarthCover",
  "location",
  "remote sensing",
  "topographic maps",
  "topography"
]
                                        

                                            {
  "name": "U.S. Geological Survey",
  "@type": "org:Organization"
}
                                        

                                            [
  "Geospatial"
]