{
    "tag": 14993,
    "title": "Topographic point cloud of the Los Padres Reservoir delta, Carmel River valley, CA, 2017-11-01",
    "pubdate": "20230111",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/P9J9CHOH",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/pcmsc\/DataReleases\/ScienceBase\/DR_P9J9CHOH\/LosPadresReservoir_2017-11-01_pointcloud_metadata.faq.html",
    "format": null,
    "email": null,
    "descript": "This portion of the data release presents a topographic point cloud of the exposed Los Padres Reservoir delta where the Carmel River enters the reservoir. The point cloud was derived from structure-from-motion (SfM) processing of aerial imagery collected with an unoccupied aerial system (UAS) on 2017-11-01. The point cloud has 115,819,907 points with an average point density of 611 points per-square meter. Each point in the point cloud contains an explicit horizontal and vertical coordinate, color, intensity, and classification. Classification was performed on the point cloud to identify ground and low-noise points within the point cloud. Additional portions of the point cloud within the horizontal extent of the reservoir water surface were classified as water points (class 9) using a polygon digitized from the orthomosaic imagery also derived from this survey. Water areas on the exposed delta surface including ponded water and areas covered by the Carmel River were not classified as water. The raw imagery used to create these point clouds 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 70 percent overlap between images from adjacent lines. The camera was triggered at 1 Hz using a built-in intervalometer. 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 raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Twenty temporary ground control points (GCPs) consisting of small square tarps with black-and-white cross patterns were distributed throughout the area to establish survey control. The GCP positions were measured using real-time kinematic (RTK) GPS, using corrections from a GPS base station located on a benchmark designated SFML, located approximately 1 kilometer from the study area. The point cloud is formatted in LAZ format (LAS 1.2 specification).",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Logan, Joshua B.",
            "role": "Author"
        },
        {
            "name": "East, Amy E.",
            "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": "006",
            "name": "elevation",
            "scope": "Height above or below sea level, for example altitude, bathymetry, digital elevation models, slope, derived products, DEMs, TINs"
        },
        {
            "thcode": 15,
            "code": "008",
            "name": "geoscientificInformation",
            "scope": "Information pertaining to earth sciences, for example geophysical features and processes, geology, minerals, sciences dealing with the composition, structure and origin of the earth's rocks, risks of earthquakes, volcanic activity, landslides, gravity information, soils, permafrost, hydrogeology, groundwater, erosion"
        },
        {
            "thcode": 23,
            "code": "22",
            "name": "Bathymetry and Elevation",
            "scope": "Includes measures of the height of a location above or below a reference surface. Bathymetry is the elevation of the Earth's surface beneath a body of water, especially the ocean, typically determined by measurements of depth from the water surface at mean lower low water. Distributions are topographic maps and bathymetric charts based on collected data and also include smoothed or gridded maps of bathymetry and elevation from observational data or other associated factors. Assessment data types include models of ecological value, economic value, or current rates of alterations due to erosion, accretion, climate change, and other stressors (for example, wetland habitat loss). Predictions are the results of models or projections of future distributions, values, or ecological impacts of bathymetry, including predicted changes due to natural and human forces such as erosion, deposition, sea-level rise, and dredging activities; predictions also include the results of scenario-based models of bathymetry changes under different management strategies."
        },
        {
            "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": "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": "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\/63782af4d34ed907bf704e37?name=LosPadresReservoir_2017-11-01_pointcloud_browse.jpg&allow=openTrue",
            "description": "Perspective view of the topographic point cloud from the 2017-11-01 UAS survey."
        }
    ],
    "fan": [
        "2017-635-FA"
    ]
}