m.lulc.read

NAME

m.lulc.read - Extracts Landuse/Landcover data in the ASCII Composite Theme Grid (CTG) data format distributed by the USGS in to a working file for m.lulc.USGS .
(GRASS Data Import/Processing Program)

SYNOPSIS

dd [if=tapedev] ibs=input block_size cbs=80 conv=unblock | m.lulc.read arg1

DESCRIPTION

m.lulc.read extracts USGS Land Use/Land Cover data distributed in the ASCII CTG format. Extracted data is placed into a file specified by arg1. m.lulc.read should be used prior to using the GRASS program m.lulc.USGS .

m.lulc.read reads the data from standard input, allowing the user to pipe in the data from a file.

Data can also be read directly from the 1/2-inch magnetic tape distributed by USGS, by using the UNIX command dd.

Parameters:

if=tapedev: The pathname of the input tape drive (usually /dev/rmt0).
ibs=input: The physical blocking value of the data on tape, usually written on the tape spool. If this value is unknown, run m.examine.tape prior to m.lulc.read.
cbs: This is the conversion blocking factor for ASCII CTG file and is by default set to 80.
conv: Set conv to unblock when extracting ASCII CTG data.
arg1: The name of the output file where the data will be stored in binary format.

EXAMPLES

READING FROM A FILE:

m.lulc.read outfile < infile

The above command will read the data from infile and place the results into outfile. Note that infile must be extracted from the USGS CTG 1/2 magnetic tape using the UNIX dd command:

dd if=/dev/rmt0 of=infile ibs=32000 cbs=80 conv=unblock

READING DIRECTLY FROM 1/2 INCH MAGNETIC TAPE:

dd if=/dev/rmt0 ibs=32000 cbs=80 conv=unblock | m.lulc.read outfile

The above command will extract data with a blocksize of 32000 from /dev/rmt0, and put the results in the file outfile.

AUTHOR

Kenneth Shepardson, Spectrum Sciences & Software, Inc. (904) 862-3031