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Homer, Alaska 1 arc-second DEM

The 1-second Homer Alaska Elevation Grid provides bathymetric data in ASCII raster format of .89-second resolution in geographic coordinates. This grid is strictly for tsunami inundation modeling

Cite this dataset when used as a source.

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Distribution Formats
  • ESRI Arc ASCII (Version: 1)
    • File Compression: WINZIP
Distributor Distributor information not available
No point of contact available for this dataset
Documentation links not available.
    Publisher information not available.
  • publication: 2002-01-01
Edition: 2002
Data Presentation Form: mapDigital
Dataset Progress Status Complete
Data Update Frequency: Irregular
Supplemental Information: This grid was developed through funding from the National Tsunami Hazard Mitigation Program. It will be updated as better data become available.
Purpose: This grid was constructed for use in tsunami inundation modeling
Time Period: Unknown  to  Unknown
Spatial Reference System:
Spatial Bounding Box Coordinates:
N: 59.67
S: 59.58
E: -151.37
W: -151.56
Spatial Coverage Map:
  • DEM > Digital Elevation Model
  • H: 1 meter - < 30 meters
  • V: < 1 meter
  • Coastal Relief
  • Gridded elevations
  • Continent > North America > United States of America > Southcentral Alaska
  • Homer
  • Kenai Peninsula Borough
  • Cook Inlet
  • Kachemak Bay
Use Constraints No constraint information available
Fees Fee information not available.
Source Datasets
  • GEODAS Vol 2, Ver 4.1 and Global Relief
    • Description of Source: Source Contribution: bathymetric data values; Source Type: online
    • Temporal extent used:  1890-01-01  to  2001-01-01
  • 1:25000 and 1:63360 hydrographic vectors, 7.5-minute digital raster graphics
    • Description of Source: Source Contribution: topographic elevation contours and shoreline; Source Type: online
    • Temporal extent used:  1982-01-01  to  1982-01-01
Lineage Statement Lineage statement not available.
Processing Steps
  • Each raw data source was converted into ESRI ArcGIS formats. The resulting files were converted and adjusted to predetermined projection (geographic), horizontal datum (NAD27), and vertical datum (MHW) using the ArcInfo PROJECT command and ArcView Spatial Analyst MAP CALCULATOR algorithm. A polyline shapefile was created to represent the coastline. The coastline is a culmination of USGS hydrographic vectors, USACE marina data, and local photogrammetric data. A TIN (Triangulated Irregular Network) was created using bathymetric data points and coastline points using ArcInfo CREATETIN. A 0.88-second grid was created using TINLATTICE. The data was assessed for quality using ArcView Spatial Analyst. The grid was compared to its raw dataset. The 0.88-second grid was clipped to requested coordinates. 62 analog photogrammetric maps were scanned into TIFF format by the Alaska Tsunami Mapping Team and transferred to the NOAA Center for Tsunami Inundation Mapping Efforts. The TIFF files were georeferenced and 2-foot topographic contours from 38 images covering the Homer region area were digitized. The contours were converted to predetermined vertical datum and units. A TIN was created using the digitized contours, USACE topographic points and contours, USGS DRG 10-meter contours, and coastline using ArcInfo CREATETIN. A 0.88-second topographic grid was created using TINLATTICE and clipped to requested coordinates. The data were assessed for quality using ArcView Spatial Analyst by comparing raw datasets. The topographic grid was updated with the Aeromap U.S. LIDAR data. The LIDAR data grid was analyzed for quality and converted to predetermined projection, datum, and resolution. The LIDAR data was compared to other topographic data sources and then merged with the original grid, superseding earlier data. Consistency between the LIDAR coverage area and older topographic data was verified. The final topographic grid was analyzed for quality. The topographic and bathymetric grids were merged into a single grid and analyzed for quality. Data were assessed for quality by comparing with original sources, corresponding sources, and control data. Continuity between old and new data were assessed and errors were corrected. The final grid was analyzed for blunders, systematic errors, and logical consistency.
  • Metadata imported.
Processing Environment Native Dataset Environment: Microsoft Windows 2000 Version 5.2 (Build 3790) Service Pack 2; ESRI ArcCatalog

Metadata Last Modified: 2015-09-03

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