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Structure-from-Motion Products - Prime Hook National Wildlife Refuge, Delaware - Orthomosaic: 2020

Metadata Updated: November 13, 2025

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.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date September 13, 2025
Metadata Updated Date November 13, 2025

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date September 13, 2025
Metadata Updated Date November 13, 2025
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/usgs-62962748d34ec53d276ba940
Data Last Modified 2022-10-24T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id c8505572-65aa-4b22-8013-999c42f41146
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial -75.3453, 38.7529, -75.1588, 38.9824
Source Datajson Identifier True
Source Hash 0925e9dd90fc572049e7e471c7771027811abd47013c60e458aaef054af6c0f5
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -75.3453, 38.7529, -75.3453, 38.9824, -75.1588, 38.9824, -75.1588, 38.7529, -75.3453, 38.7529}

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