{
    "tag": 15769,
    "title": "Orthomosaic imagery from the UAS survey of the coral reef off Waiakane, Molokai, Hawaii, 24 June 2018",
    "pubdate": "20220321",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/P9XZT1FK",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/pcmsc\/DataReleases\/ScienceBase\/DR_P9XZT1FK\/Waiakane_2018-06-24_orthomosaic_25mm_metadata.faq.html",
    "format": null,
    "email": null,
    "descript": "This portion of the data release presents a high-resolution orthomosaic image of the coral reef off Waiakane, Molokai, Hawaii. The orthomosaic has a resolution of 2.5 centimeters (cm) per pixel and was derived from structure-from-motion (SfM) processing of aerial imagery collected with an unoccupied aerial system (UAS) on 24 June 2018. The raw imagery used to create the orthomosaic was acquired using a UAS fitted with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 75 percent overlap between images from adjacent lines. The UAS was flown at an approximate altitude of 100 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.6 centimeters per pixel. The camera was triggered at 1 Hz using a built-in intervalometer. The raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Although imagery was collected using both a circular polarizing filter and with no polarizing filter, only the non-polarized imagery was used for the creation of the orthomosaic. SfM photogrammetry was used to derive a preliminary digital surface model (DSM) from this imagery which was used as a surface for orthorectification and mosaicking. The orthomosaic image is provided in a three-band RGB format, with 8-bit unsigned integer values compressed using high-quality JPEG compression. The image has been formatted as a cloud-optimized GeoTIFF with internal overviews and masks to facilitate cloud-based queries and display.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Logan, Joshua B.",
            "role": "Author"
        },
        {
            "name": "Storlazzi, Curt D.",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "15",
            "name": "aerial photography",
            "scope": "The process of taking pictures with a camera from an aircraft. Use for both the process of photography from the air and the images produced by the process."
        },
        {
            "thcode": 2,
            "code": "468",
            "name": "geomorphology",
            "scope": "Branch of geology dealing with surface land features and the processes that create and change them."
        },
        {
            "thcode": 2,
            "code": "474",
            "name": "geospatial datasets",
            "scope": "Collections of related digital information that are geographically referenced."
        },
        {
            "thcode": 2,
            "code": "2046",
            "name": "image mosaics",
            "scope": "Composite images formed by overlapping existing images, typically arranged to achieve greater spatial coverage."
        },
        {
            "thcode": 2,
            "code": "981",
            "name": "remote sensing",
            "scope": "Acquiring information about a natural feature or phenomenon, such as the Earth's surface, without actually being in contact with it. USGS remote sensing is usually carried out with airborne or spaceborne sensors or cameras."
        },
        {
            "thcode": 2,
            "code": "2265",
            "name": "structure from motion",
            "scope": "Mathematical analysis, using photogrammetric principles, of multiple images that depict the same subject from different angles to derive geometrical information and relationships in three-dimensional space that are not inherent in any single image. Often used for deriving land elevation or large scale orthoimagery from a collection of aerial photographs."
        },
        {
            "thcode": 2,
            "code": "1749",
            "name": "topographic maps",
            "scope": "Maps depicting the elevation and relief of the land surface or depth of a water body (bathymetry) in an area, usually shown using contour lines.  Typically these maps include manmade features and administrative boundaries as well as vegetation and hydrographic features."
        },
        {
            "thcode": 2,
            "code": "1176",
            "name": "topography",
            "scope": "Configuration of the land surface and sea floor."
        },
        {
            "thcode": 15,
            "code": "010",
            "name": "imageryBaseMapsEarthCover",
            "scope": "Base maps, for example land\/earth cover, topographic maps, imagery, unclassified images, annotations, digital ortho imagery"
        },
        {
            "thcode": 23,
            "code": "23",
            "name": "Substrate",
            "scope": "Represents the character and composition of the surface and near surface of the sea floor in subtidal or intertidal areas, as defined in the Substrate Component of CMECS or in similar classification systems. Distributions are records of substrate characteristics based on visual or photographic inspection or on analysis of samples and cores, and they also include interpretive maps classifying areas on the basis of combinations of observations, hydrodynamic models, or geological models. Assessments include evaluations of present ecological or economic values of substrate distributions, drivers of substrate change, and functions of substrates. Predictions are the results of models or projections of future substrate distributions, values, or ecological impacts, including predicted substrate changes due to natural and human forces including erosion, accretion, sea-level change, extraction, trawling, or other factors; and they are the results of scenario-based models of substrate changes on ecological or economic values under different management strategies or other human alterations."
        },
        {
            "thcode": 61,
            "code": "450",
            "name": "aerial and satellite photography",
            "scope": "used for vertical or oblique photography of the Earth taken from aircraft or satellites; do not use for air-to-air photography."
        },
        {
            "thcode": 61,
            "code": "447",
            "name": "altimetry",
            "scope": "used for all instruments and techniques that determine altitude, either directly or remotely, including (but not limited to) pressure altimeters, radar altimeters, GPS, and LIDAR."
        },
        {
            "thcode": 61,
            "code": "14",
            "name": "coastal processes",
            "scope": "oceanographic and geologic processes that cause changes to the shoreline and coastal zone."
        },
        {
            "thcode": 61,
            "code": "283",
            "name": "coral reefs",
            "scope": "aquatic biogenic structures supporting a complex community of organisms with distinct roles in relation to the whole: framework builders (corals), along with binders, bafflers, dwellers, and destroyers."
        },
        {
            "thcode": 61,
            "code": "161",
            "name": "fringing reef",
            "scope": "coral reef attached to the shore."
        },
        {
            "thcode": 61,
            "code": "452",
            "name": "orthophotography",
            "scope": "aerial photography corrected for distortion (\"orthorectified\") to create an image with uniform scale."
        },
        {
            "thcode": 61,
            "code": "445",
            "name": "photography",
            "scope": "limited to photography for scientific purposes."
        },
        {
            "thcode": 61,
            "code": "159",
            "name": "reef",
            "scope": "used for 1) shallow-water biotic reefs such as coral reefs, 2) biotic reefs preserved in the geologic record, and 3) rocky outcrops on the sea floor that create a hazard to navigation."
        },
        {
            "thcode": 61,
            "code": "449",
            "name": "remote sensing",
            "scope": "generally used for the acquisition of images or other data from aircraft or satellites; also used for ground-based systems for collecting data at a distance."
        }
    ],
    "place_term": [],
    "image": [
        {
            "name": "https:\/\/www.sciencebase.gov\/catalog\/file\/get\/61ae9e45d34eb622f69a732b?name=Waiakane_2018-06-24_orthomosaic_25mm_browse.jpg&allowOpen=true",
            "description": "Orthomosaic image from the UAS survey of the coral reef off Waiakane, Molokai, HI."
        }
    ],
    "fan": [
        "2018-617-FA"
    ]
}