Geoprocessing tool reference > Conversion toolbox > To Raster toolset > Tools
DEM To Raster (Conversion) |
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Release 9.2
Last modified April 2, 2008 |
Print all topics in : "Tools" |
Converts a digital elevation model (DEM) in a United States Geological Survey (USGS) format to a raster dataset.
Learn more about how DEM To Raster tool works
Usage tips
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The resulting raster will have square cells if it is a GRID. If the DEM that is converted to GRID has a different sample point spacing in the x and y directions, it is resampled during the conversion process. It is resampled using bilinear interpolation at a cell size equal to the smaller of the point spacings of the DEM in the x or y.
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For output to a grid raster, DEM To Raster transfers the projection and units information contained in the DEM header record to a map projection file in the output grid directory. If the output raster is not a grid, the projection information will be transferred to the .aux file.
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The majority of DEM files are integer. If a floating-point DEM is converted with the output data type set to INTEGER, the values will be truncated. However, it is not easy to identify if a particular DEM file happens to be floating point. To prevent inadvertent loss of floating-point data when it exists, the default output data type of the raster will be floating point. The only cost is for integer DEMs, the resulting raster will occupy more disk space than it needs. This can be rectified by subsequently performing a Math INT operation on the raster. If the input dataset is known to be an integer type, then the INTEGER option can be selected instead of the default.
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DEM To Raster applies the spatial resolution value stored in the DEM. In USGS DEMs, this information is stored in Data Element 14 in Logical Record Type A. The spatial resolution value is used to scale all input DEM elevation values.
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The following environments affect this tool: current workspace, scratch workspace, output coordinate system, output extent, output has Z values, Z resolution, output CONFIG keyword, output spatial grid 1,2,3, output XY domain, output Z domain, pyramid, raster statistics, compression, and tile size.
Command line and Scripting
Command line syntax
An overview of the Command Line window
DEMToRaster_conversion <in_dem_file> <out_raster> {FLOAT | INTEGER} {z_factor}
| Parameter | Explanation | Data Type |
| <in_dem_file> |
The input USGS DEM file. The DEM must be standard USGS 7.5 minute, 1 degree, or any other file in the USGS DEM format. The DEM may be in either fixed or variable record-length format. |
File |
| <out_raster> |
The output raster dataset to be created. When not saving to a geodatabase, specify .tif for a TIFF file format, .img for an ERDAS IMAGINE file format, or no extension for a GRID file format. |
Raster Dataset |
| {FLOAT | INTEGER} |
Data type of the output raster dataset.
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String |
| {z_factor} |
The number of ground x,y units in one surface Z-unit. The Z-factor adjusts the units of measure for the Z-units when they are different from the x,y units of the input surface. The Z-values of the input surface are multiplied by the Z-factor when calculating the final output surface. If the x,y units and Z-units are in the same units of measure, the Z-factor is 1. This is the default. If the x,y units and Z-units are in different units of measure, the Z-factor must be set to the appropriate factor, or the results will be incorrect. For example, if your Z-units are feet, and your x,y units are meters, you would use a Z-factor of 0.3048 to convert your Z-units from feet to meters (1 foot = 0.3048 meters). |
Double |
Command line example
DEMToRaster_conversion d:\data\USGSelevation d:\images.mdb\DEM FLOAT 0.3048
Scripting syntax
About getting started with writing geoprocessing scripts
DEMToRaster_conversion (in_dem_file, out_raster, data_type, z_factor)
| Parameter | Explanation | Data Type |
| in_dem_file (Required) |
The input USGS DEM file. The DEM must be standard USGS 7.5 minute, 1 degree, or any other file in the USGS DEM format. The DEM may be in either fixed or variable record-length format. |
File |
| out_raster (Required) |
The output raster dataset to be created. When not saving to a geodatabase, specify .tif for a TIFF file format, .img for an ERDAS IMAGINE file format, or no extension for a GRID file format. |
Raster Dataset |
| data_type (Optional) |
Data type of the output raster dataset.
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String |
| z_factor (Optional) |
The number of ground x,y units in one surface Z-unit. The Z-factor adjusts the units of measure for the Z-units when they are different from the x,y units of the input surface. The Z-values of the input surface are multiplied by the Z-factor when calculating the final output surface. If the x,y units and Z-units are in the same units of measure, the Z-factor is 1. This is the default. If the x,y units and Z-units are in different units of measure, the Z-factor must be set to the appropriate factor, or the results will be incorrect. For example, if your Z-units are feet, and your x,y units are meters, you would use a Z-factor of 0.3048 to convert your Z-units from feet to meters (1 foot = 0.3048 meters). |
Double |
Data types for geoprocessing tool parameters
Script example
# DEMToRaster_sample.py
# Description:
# Converts a DEM in USGS format to a raster.
# Requirements: None
# Author: ESRI
# Date: Oct 20, 2005
# Import system modules
import arcgisscripting
# Create the Geoprocessor object
gp = arcgisscripting.create()
try:
# Set local variables
InDemFile = "C:/data/example.dem"
OutRaster = "C:/data/raster1"
# Process: DEMToRaster_conversion
gp.DEMToRaster_conversion(InDemFile, OutRaster, "INTEGER")
except:
# Print error message if an error occurs
print gp.GetMessages()
Map Algebra syntax
See DEMGrid.
ArcObjects syntax
See ImportFromUSGSDEM.