Hillshades for the main 8 Hawaiian Islands

These hillshade datasets were derived from USGS 7.5' DEM Quads for the main 8 Hawaiian Islands. Individual DEM quads were first converted to a common datum, and vertical unit, and subsequently mosaicked in ArcGIS 9.x. The hillshade were created from these DEMs using the Hillshade function in ArcGIS 9.2's Spatial Analyst Extension. For all the hillshades, the altitude was set at 45, the Z factor at 1 and the output cell size at 10. The azimuth was set to 45 for the Hawaii (Big Island), Maui and Kauai hillshades. The azimuth was set to 315 for the remaining island hillshades. All rasters are 16 bit signed integers with a spatial resolution of 10 meters. They are in the ERDAS Imagine (.img) format and are referenced to the NAD83 UTM coordinate system. The hillshade for Hawaii (Big Island) is in UTM zone 5N, and the hillshades for the remaining 7 islands are in UTM zone 4N. On this metadata sheet, the bounding coordinates and row and column counts are for a hypothetical 10m grid that would contain the 8 main Hawaiian Islands. For bounding coordinates and the number of rows and columns for each actual, individual hillshade, users should consult their respective layer properties.

These datasets were created to be used in GIS for visualization and analysis.

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For more infomration regarding digital elevation models, please refer to the following URL: http://erg.usgs.gov/isb/pubs/factsheets/fs04000.html For more information regarding the hillshade computation, please refer to the following URL: http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?id=4360&pid=4351&topicname=Hillshade

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.

Please cite the National Oceanic & Atmospheric Administration.

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350

The accuracy of these DEMs (and hillshades) depend on the source and resolution of the data samples. DEM data accuracy is derived by comparing linear interpolation elevations in the DEM with corresponding map location elevations and computing the statistical standard deviation or root-mean-square error (RMSE). The RMSE is used to describe the DEM accuracy. For 7.5-minute DEM's derived from a photogrammetric source, 90 percent have a vertical accuracy of 7-meter RMSE or better and 10 percent are in the 8- to 15-meter range. For 7.5- and 15-minute DEM's derived from vector or DLG hypsographic and hydrographic source data, an RMSE of one-half of a contour interval or better is required. The 1-degree DEM data have an absolute accuracy of 130 meters horizontally and 30 meters vertically.

The accuracy of these DEMs (and hillshades) depend on the source and resolution of the data samples. DEM data accuracy is derived by comparing linear interpolation elevations in the DEM with corresponding map location elevations and computing the statistical standard deviation or root-mean-square error (RMSE). The RMSE is used to describe the DEM accuracy. For 7.5-minute DEM's derived from a photogrammetric source, 90 percent have a vertical accuracy of 7-meter RMSE or better and 10 percent are in the 8- to 15-meter range. For 7.5- and 15-minute DEM's derived from vector or DLG hypsographic and hydrographic source data, an RMSE of one-half of a contour interval or better is required. The 1-degree DEM data have an absolute accuracy of 130 meters horizontally and 30 meters vertically.

The accuracy of these DEMs (and hillshades) depend on the source and resolution of the data samples. DEM data accuracy is derived by comparing linear interpolation elevations in the DEM with corresponding map location elevations and computing the statistical standard deviation or root-mean-square error (RMSE). The RMSE is used to describe the DEM accuracy. For 7.5-minute DEM's derived from a photogrammetric source, 90 percent have a vertical accuracy of 7-meter RMSE or better and 10 percent are in the 8- to 15-meter range. For 7.5- and 15-minute DEM's derived from vector or DLG hypsographic and hydrographic source data, an RMSE of one-half of a contour interval or better is required. The 1-degree DEM data have an absolute accuracy of 130 meters horizontally and 30 meters vertically.

These hillshades cover the full land extent of the main 8 Hawaiian islands (i.e., Hawaii, Maui, Kahoolawe, Lanai, Molokai, Oahu, Kauai and Niihau). They were created from 7.5' quad DEMs that were mosaiced together and exported as ESRI grids. Data profiles for this product may not be consistent due to the variable angle between true north and grid north in the UTM coordinate system.

All users should independently analyze the dataset according to their own needs and standards to determine data usability.