dem2viff(1)

PROGRAM
dem2viff - Convert DEM format data to VIFF format.

SYNTAX

dem2viff

-i  Input DEM File

-o  Output VIFF File

[-s]
    subsampling factor

[-l]
    Location Options:
    0 (No Location Data),
    or 1 (Explicit Location Data)
       [default = 0]

[-V]
    Gives the version for dem2viff

[-U]
    Gives the usage for dem2viff

[-P]
    Prompts for command line options

[-A [file1]]
    Creates the answer file called dem2viff.ans or file1

[-a [file1]]
    Uses dem2viff.ans or file1 as the answer file

DESCRIPTION
dem2viff converts digital elevation map data in the format distibuted by the United States Geological Survey to viff format so that it may be used by the khoros system.

DEM data in both the 7.5-minute and 1-degree formats can be used.

For large files, the data may be subsampled using the -s flag before it is written to the output viff file.

The output may be written with location data using the -l flag. If explicit locations are choosen, the units that the locations are given in depend on the format of the input file. Locations for 7.5-minute data will be given in utm meters, and locations for 1-degree data will be given in arc seconds.

REQUIRED ARGUMENTS

-i  type: infile
    desc: Input DEM File

-o  type: outfile
    desc: Output VIFF File

OPTIONAL ARGUMENTS

-s  type: integer
    desc: subsampling factor
    default: 1
    bounds: value > 0

-l  type: integer
    desc: Location Options
    allowed values:
    0 (No Location Data),
    or 1 (Explicit Location Data)

EXAMPLES
dem2viff -i dem.image -o viff.image -s 5 -l 1

This command reads the DEM data in file dem.image, converts it to viff format, and store it in file viff.image. A subsampling factor of 5 is used, which means that every 5th point of DEM data is actually used in the viff output, and explicit location data is specified.

SEE ALSO
intro(1), verror(3), vgparms(3), vutils(3), ldem2viff(3)

RESTRICTIONS
dem2viff works with both 7.5-minute and 1-degree DEM files, but the elevation units in either format must be meters. The ground units in a 7.5-minute DEM file must also be meters, and the ground units in a 1-degree DEM file must be arc seconds. A 7.5-minute DEM must use utm coordinates, and a 1-degree DEM must use geographical coordinates. This program reads fixed format data, so it is very sensitive to the spacing of the fields in the input file. If the input file format deviates in any way from the standard DEM format the program will crash.

This program has received only minimal testing with 7.5-minute DEM files.

COPYRIGHT
Copyright 1991, University of New Mexico. All rights reserved.