| snippet:
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Provide high resolution terrain elevation data from the Nenana-Totchaket Aerial Survey & Mapping dataset. |
| summary:
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Provide high resolution terrain elevation data from the Nenana-Totchaket Aerial Survey & Mapping dataset. |
| accessInformation:
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Alaska Department of Natural Resources |
| thumbnail:
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| maxScale:
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9009.26119250471 |
| typeKeywords:
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["Data","Service","Image Service","ArcGIS Server"] |
| description:
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The hydro-flattened bare earth digital elevation model (DEM) represents the earth's surface with all vegetation and anthropogenic features removed. It is derived from NIR lidar data using TIN processing of the ground point returns. All rivers greater than 30 meters in width and lakes at least 150 square meters in size have been flattened to consistent elevations. Water boundary polygons were developed using an algorithm which weights lidar-derived slopes, intensities, and return densities to detect the water's edge. Elevation values were then assigned to the water's edge from the lidar data creating 3D breaklines enforced during model creation to flatten water bodies. Some elevation values have been interpolated across areas in the ground model where there is no elevation data (e.g. under dense vegetation). The horizontal datum for this dataset is NAD83 (2011), the vertical datum is NAVD88, Geoid 12B, and the data is projected in UTM Zone 6. Units are in Meters. Quantum Spatial collected the Nenana-Totchaket Aerial Survey & Mapping lidar data for Alaska Department of Natural Resources between 07/11/2020 and 07/31/2020. |
| licenseInfo:
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In some areas of heavy vegetation or forest cover, there may be relatively few ground points in the lidar data. TINing the points produces large triangles and hence the elevations may be less accurate within such areas. Elevation values for open water surfaces are derived from waters edge breaklines. Triangles were created across water surfaces by interpolating from the nearest breakline elevation points. |
| catalogPath:
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| title:
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Nenana_Totchaket_2020_dtm |
| type:
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Image Service |
| url:
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https://geoportal.alaska.gov/arcgis |
| tags:
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["lidar","Light Detection and Ranging","elevation data","topography","bare earth","hydro-flattened","breaklines","DEM","digital elevation model","Nenana","Alaska","Yukon-Koyukuk"] |
| culture:
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en-US |
| name:
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Nenana_Totchaket_2020_dtm |
| guid:
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| minScale:
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3.69019338444993E7 |
| spatialReference:
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NAD_1983_2011_UTM_Zone_6N |