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Structure-from-Motion Products - Prime Hook National Wildlife Refuge, Delaware - Orthomosaic: 2021

Metadata Updated: October 28, 2023

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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Metadata Created Date June 1, 2023
Metadata Updated Date October 28, 2023

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date October 28, 2023
Publisher U.S. Geological Survey
Identifier USGS:629627b6d34ec53d276ba94b
Data Last Modified 20221024
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Harvest Object Id 6d13b2a2-55e9-404b-bc54-00fc2202d8ee
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -75.3453,38.7529,-75.1588,38.9824
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash 27a72427ab5ae6f2c4c0a2bc7209e16ed97c9d167beeab9c541dd8cefc6a7144
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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