The cell values for this grid represent illumination value from 0 - 255. The Shade Relief grids were created from the a 30 meter grid when available and the USGS DEM where 30 meter data is not available, for example Northwest Florida Panhandle. The SHADRL grids created from USGS DEM's were converted from Z values in meters to Z values of feet by multiplying Z * 3.281.
Shaded Relief Surfaces are mainly used as Background in mapping and Displaying Data. It is usually displayed as an Image instead of a Grid. When wanting to perform analysis it is recommended that one use a Digital Elevation Model.
Scale is an important factor in data usage. Certain scale data sets are not suitable for some projects, analysis, or modeling purposes. Please be sure you are using the best available data.
1:24000 scale data sets are recommended for projects that are at the county level. 1:24000 data should NOT be used for high accuracy base mapping such as property parcel boundaries.
1:100000 scale data sets are recommended for projects that are at the multi-county or regional level. 1:250000 scale data sets are recommended for projects that are at the regional or state level or larger.
Shaded Relief Surfaces are mainly used as Background in mapping and Displaying Data. It is usually displayed as an Image instead of a Grid. When wanting to perform analysis it is recommended that one use a Digital Elevation Model.
Shaded Relief Surfaces are mainly used as Background in mapping and Displaying Data. It is usually displayed as an Image instead of a Grid. When wanting to perform analysis it is recommended that one use a Digital Elevation Model.