{
    "tag": 19402,
    "title": "Point clouds showing erosion in an approximately 13 km long section of the Big Sur coast, California, between two flights and projected onto topography from the second flight",
    "pubdate": "20250903",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/P13FEC44",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/pcmsc\/DataReleases\/CMGDS_DR_tool\/DR_P13FEC44\/BigSur_M3C2_metadata.faq.html",
    "format": null,
    "email": null,
    "descript": "Presented here are point clouds of approximately 13 km of the Big Sur coastline each showing erosion (as positive values) between two dates. The point cloud coordinates reflect topography at the later date. Change detection was computed using point clouds published in this data release and developed with structure-from-motion on aerial photography collected by the U.S. Geological Survey (USGS) using an oblique plane-mounted camera system. Ground points were identified in these point clouds using LAStools and manual reclassification of some protruding rocks as ground. Non-ground points were then removed, and the point clouds were clipped to an area of interest (AOI) of the cliff face using LASTools. We used the Multiscale Model-to-Model Cloud Comparison (M3C2) tool to calculate change in the cliff face between two flights. The M3C2 point cloud is a subsampled (at 0.25-m resolution) version of the point cloud of the second flight and M3C2 distances reflect erosion that occurred between the previous flight and this flight. This point cloud was then filtered using a combination of the Visible Atmospherically Resistant Index (VARI) and manual assessment to eliminate changes that do not reflect erosion, such as vegetation changes. It was then additionally filtered to include only points that the M3C2 algorithm considered significant (low uncertainty). Point cloud contains XYZ data and the following scalar fields: G-R\/G+R-B (VARI), M3C2 distance, distance uncertainty, and significant change. Point cloud coordinates are in NAD83 UTM Zone 10 meters. The AOI was created in ArcGIS Pro 3.3.1. M3C2 distances, VARI calculation, and filtering were calculated in CloudCompare v2.12.4. Note that some flight dates represented in the topographic point cloud dataset will not have an associated M3C2 file because the product showed no erosion but substantial vegetation noise and was thus excluded.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Dow, Helen W.",
            "role": "Author"
        },
        {
            "name": "Warrick, Jonathan A.",
            "role": "Author"
        },
        {
            "name": "Ritchie, Andrew C.",
            "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": "1799",
            "name": "coastal processes",
            "scope": "Processes unique to coastal areas including longshore transport, beach erosion, storm surge, shoreline change, delta formation, barrier island migration, beach stabilization by vegetation"
        },
        {
            "thcode": 2,
            "code": "531",
            "name": "hazards",
            "scope": "Potential dangers from both natural processes (e.g., earthquakes, floods, and climate change) and human impacts on the environment."
        },
        {
            "thcode": 2,
            "code": "574",
            "name": "image analysis",
            "scope": "Pattern analysis of the shapes and textures of images to identify features and derive information about them."
        },
        {
            "thcode": 2,
            "code": "575",
            "name": "image collections",
            "scope": "Visible representations of objects or earth properties produced by cameras, spectral instruments, or as graphical representations of measurements."
        },
        {
            "thcode": 2,
            "code": "639",
            "name": "landslides",
            "scope": "Downslope movement of rock, soil, or artificial fill under the influences of gravity."
        },
        {
            "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": "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": 15,
            "code": "010",
            "name": "imageryBaseMapsEarthCover",
            "scope": "Base maps, for example land\/earth cover, topographic maps, imagery, unclassified images, annotations, digital ortho imagery"
        },
        {
            "thcode": 15,
            "code": "018",
            "name": "transportation",
            "scope": "Means and aids for conveying persons or goods, for example roads, airports\/airstrips, shipping routes, tunnels nautical charts, vehicle or vessel location, aeronautical charts, railways"
        },
        {
            "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": "3",
            "name": "agents of coastal change",
            "scope": "natural phenomena and human activities that cause changes in coastal processes, landscapes, and ecosystems."
        },
        {
            "thcode": 61,
            "code": "32",
            "name": "anthropogenic agents of coastal change",
            "scope": "human activities that cause changes in coastal processes, landscapes, and ecosystems."
        },
        {
            "thcode": 61,
            "code": "2",
            "name": "coastal change hazards topics",
            "scope": null
        },
        {
            "thcode": 61,
            "code": "349",
            "name": "coastal landslides",
            "scope": "slope failures along a coast, often triggered by storm events."
        },
        {
            "thcode": 61,
            "code": "18",
            "name": "coastal landsliding",
            "scope": "used for both subaerial and submarine landsliding in the coastal zone."
        },
        {
            "thcode": 61,
            "code": "14",
            "name": "coastal processes",
            "scope": "oceanographic and geologic processes that cause changes to the shoreline and coastal zone."
        },
        {
            "thcode": 61,
            "code": "54",
            "name": "coastal sediment budget",
            "scope": "natural phenomena or human activities that alter the balance between sediment sources and sinks in the coastal system."
        },
        {
            "thcode": 61,
            "code": "91",
            "name": "coastal zone management",
            "scope": "used for formal programs at any level of government, such as the Coastal Zone Management Program (a federal-state partnership in the United States)."
        },
        {
            "thcode": 61,
            "code": "57",
            "name": "effects of coastal change",
            "scope": "changes in coastal processes, landscapes, and ecosystems."
        },
        {
            "thcode": 61,
            "code": "716",
            "name": "geomorphology",
            "scope": "the study of landforms and their evolution."
        },
        {
            "thcode": 61,
            "code": "323",
            "name": "hazards and disasters",
            "scope": "used for natural hazards, the risks they pose to society, and the destructive events that may result."
        },
        {
            "thcode": 61,
            "code": "73",
            "name": "human responses to coastal change",
            "scope": "actions, strategies, and policies intended to lessen current or anticipated impacts of coastal change on human populations, infrastructure, and natural ecosystems."
        }
    ],
    "place_term": [
        {
            "thcode": 1,
            "code": "fUS",
            "name": "United States",
            "scope": "country",
            "pname": "North America"
        },
        {
            "thcode": 1,
            "code": "f06053",
            "name": "Monterey",
            "scope": "county",
            "pname": "California"
        },
        {
            "thcode": 1,
            "code": "h1806",
            "name": "Central California Coastal",
            "scope": "hydrologic subregion",
            "pname": "California"
        },
        {
            "thcode": 1,
            "code": "fUS06",
            "name": "California",
            "scope": "state",
            "pname": "United States"
        }
    ],
    "image": [],
    "fan": []
}