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2018 LiDAR - Hydro Enforced Digital Terrain Model
The hydro-flattened bare earth DEM was generated using the 2018 DC lidar bare earth points and 3D hydro breaklines to a resolution of 1 m. The bare earth points that fell within 1NPS along the hydro breaklines were excluded from the DEM generation process and put into class 20 – ignored ground. This is analogous to the removal of mass points for the same reason in a traditional photogrammetrically compiled DTM. This process was done in batch using proprietary software. The technicians then used proprietary software for the production of the lidar-derived hydro-flattened bare earth DEM surface in initial grid format at 1 m GSD. Water bodies (inland ponds and lakes), inland streams and rivers, and island holes were hydro-flattened within the DEM. Once the initial, hydro-flattened bare earth DEM was generated, the tiles were checked to ensure that the grid spacing met specifications. The surface was also checked to ensure proper hydro-flattening.This dataset provided as an ArcGIS Image service. Please note, the download feature for this image service in Open Data DC provides a compressed PNG, JPEG or TIFF. The compressed GeoTIFF raster dataset is available under additional options when viewing downloads.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| contactPoint |
{
"fn": "DCGISgroup",
"@type": "vcard:Contact",
"hasEmail": "mailto:gisgroup@dc.gov"
}
|
| description | <div style='text-align:Left;'><div><div><p><span>The hydro-flattened bare earth DEM was generated using the 2018 DC lidar bare earth points and 3D hydro breaklines to a resolution of 1 m. The bare earth points that fell within 1NPS along the hydro breaklines were excluded from the DEM generation process and put into class 20 – ignored ground. This is analogous to the removal of mass points for the same reason in a traditional photogrammetrically compiled DTM. This process was done in batch using proprietary software. The technicians then used proprietary software for the production of the lidar-derived hydro-flattened bare earth DEM surface in initial grid format at 1 m GSD. Water bodies (inland ponds and lakes), inland streams and rivers, and island holes were hydro-flattened within the DEM. Once the initial, hydro-flattened bare earth DEM was generated, the tiles were checked to ensure that the grid spacing met specifications. The surface was also checked to ensure proper hydro-flattening.This dataset provided as an ArcGIS Image service. Please note, the download feature for this image service in Open Data DC provides a compressed PNG, JPEG or TIFF. The compressed GeoTIFF raster dataset is available under additional options when viewing downloads.</span></p></div></div></div> |
| distribution |
[
{
"@type": "dcat:Distribution",
"title": "ArcGIS GeoService",
"format": "ArcGIS GeoServices REST API",
"accessURL": "https://imagery.dcgis.dc.gov/dcgis/rest/services/Lidar/Hydro_Enforced_DTM_2018/ImageServer",
"mediaType": "application/json"
},
{
"@type": "dcat:Distribution",
"title": "ArcGIS Hub Dataset",
"format": "Web Page",
"accessURL": "https://opendata.dc.gov/datasets/DCGIS::2018-lidar-hydro-enforced-digital-terrain-model",
"mediaType": "text/html"
}
]
|
| identifier | https://www.arcgis.com/home/item.html?id=288c927005c84e768a57b0212c2700a6 |
| issued | 2019-11-06T14:58:06.000Z |
| keyword |
[
"DC",
"District of Columbia",
"Washington DC",
"bare earth",
"dem",
"digital elevation model",
"dtm",
"elevation",
"hydro-enforced",
"hydro-flattened",
"lidar",
"lidar2018"
]
|
| landingPage | https://opendata.dc.gov/datasets/DCGIS::2018-lidar-hydro-enforced-digital-terrain-model |
| license | https://creativecommons.org/licenses/by/4.0 |
| modified | 2022-11-28T19:11:59.000Z |
| publisher |
{
"name": "D.C. Office of the Chief Technology Officer"
}
|
| spatial | -77.1220,38.7855,-76.9007,39.0017 |
| theme |
[
"geospatial"
]
|
| title | 2018 LiDAR - Hydro Enforced Digital Terrain Model |
