1. Coastal and Marine Hazards and Resources
  2. Geoscience Data System
  3. Dataset 40889

Dataset description: Orthomosaic imagery

This portion of the data release presents a high-resolution orthomosaic image of the Liberty Island Conservation Bank Wildlands restoration site in the Sacramento-San Joaquin Delta. The orthomosaic has a resolution of 3 centimeters per-pixel and was derived from structure-from-motion (SfM) processing of aerial imagery collected with an Unmanned Aerial System (UAS) on 2018-10-23. The raw imagery used to create the orthomosaic image was acquired using two UAS fitted with Ricoh GR II digital cameras with global shutters. The UAS were flown on pre-programmed autonomous flight lines at an approximate altitude of 120 meters above-ground-level. The flight lines were oriented roughly east-west and were spaced to provide approximately 66 percent overlap between images from adjacent lines. The cameras were triggered at 1 Hz using a built-in intervalometer. The imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Ground control was established using twenty-four ground control points (GCPs) consisting of small square tarps with black-and-white cross patterns distributed throughout the mapping area. The GCP positions were measured using RTK GPS, with real-time corrections from a GPS base station located approximately 3 kilometers south of the study area. The orthomosaic imagery is provided at a resolution of 3 centimeters per-pixel, in a three-band RGB cloud-optimized GeoTIFF format, with 8-bit unsigned integer values compressed using high-quality JPEG compression.
Version1
Keywordstopography, aerial photography, topographic maps, image mosaics, geomorphology, geospatial datasets, remote sensing
Data typesPhoto
FormatGeoTIFF;
Amount416 MB

Contacts

Contact
Joshua Logan
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Location of materials and files

Public files
Metadatahttps://cmgds.marine.usgs.gov/metadata/pcmsc/DataReleases/ScienceBase/DR_P9GF8R1M/Wildlands_2018-10-23_orthomosaic.xml
Outline - Questions and answers - Text - XML

Activities and equipment

ActivityEquipment
2018-676-FAStructure from Motion - UAS
UAS mounted camera