What is GRASS? [posted twice monthly]

grass-lists-owner at max.cecer.army.mil grass-lists-owner at max.cecer.army.mil
Sun Jan 15 09:59:49 EST 1995

[The groups info.grass.user and info.grass.programmer are Usenet gateways for
 the GRASShopper Users' and Programmers' lists.  GRASS is a Geographic
 Information System developed by the US Army Corps of Engineers Construction
 Engineering Research Labs in Champaign, Illinois.

 The following is a brief blurb about GRASS from the GRASS Fact Sheet.  It
 is posted twice monthly to the newsgroups info.grass.user and

 If there are any questions about the mailing lists or the newsgroups, please
 contact grass-lists-owner at moon.cecer.army.mil .

 Rob Knauerhase [rob at amber.cecer.army.mil]  Office of GRASS Integration
 Construction Engineering Research Labs, US Army Corps of Engineers

August 1991

The Problem

     Land managers and training planners at Army installations face the
complex tasks of (1) facilitating optimal training use of available range and
maneuver areas; (2) maintaining current lands in a condition suitable for long
term training use; (3) protecting valuable natural and cultural resources; and
(4) accomodating secondary land uses, including forestry, grazing, hunting,
and recreation.  Furthermore, land management problems have become more
complicated because new, more sophisticated weapons require more maneuver and
training range area.  To fulfill these complex land use planning and land
management requirements, tools are needed to store, combine, analyze, and
display multiple map elements.

The Technology

     The U.S. Army Construction Engineering Research Laboratory's (USA-CERL)
Geographic Resources Analysis Support System (GRASS) was developed to provide
these management tools to Army environmental planners and land managers.
GRASS also has many applications for Civil Works project planning and
design.  GRASS has many capabilities, including the handling of different
representations of data:
     RASTER DATA -- raster (or grid cell type) data can be used for
analyzing, overlaying, and modeling areal features such as soil
types or forested areas.
     VECTOR DATA -- vector data can be used to represent linear features
such as roads, streams or area edges and can be combined with raster
data for display purposes or for analysis.
     POINT DATA -- point data can be used to represent landmarks or the
location of significant sites.

Other capabilities include:
     IMAGERY -- the ability to display, geo-reference, compare and
classify satellite and aerial photographic imagery.
     MAPDEV -- the ability to input map data and print hard copies on various
printers, including the ability to create output to a pen plotter that runs or
emulates HPGL.
     DBMS -- the ability to link to a Database Management System for
help in managing data.

     The GRASS system is run through the use of standardized command
line input, and can be run under X-windows or Open windows.  There is an
internal language that allows users and programmers to create
application and demonstration models and to link GRASS with other
software packages.  Users can input new data through digitization
or the use of a scanner, with a screen pointing device,
from a floppy disk, or from computer tapes.  New data can also be created
by selecting data elements from existing files for analysis.  Outputs
include statistical tables, text files, or maps that can be displayed on
a color monitor or printed on several types of hard copy printers and/or

     Hardware configurations vary from a table-top to rack mount machines,
depending on the platform available and the needs of the users.  A
minimum configuration would include a display device that can display
256 simultaneous colors, a processor running UNIX or a similar operating
system, at least 8 megabytes of system memory, at least 140 megabytes
of disk space (300 to 600 megabytes is recommended), a dumb terminal,
a line printer, graphics library, a 1/4" or 1/2" tape drive, and a mouse
pointing device.  Other options include a digitizer for map input,
any of several color printers for hardcopy output, and modems
and/or network connections to communicate with other machines.

     Current GRASS workstations include Sun, Intergraph, MacIntosh II,
CDC 4000 machines, PC-386's and PC-486's, DEC, Tektronix 88K, Silicon
Graphic's IRIS, Concurrent, Data General, IBM RISC and PS/2,
and AT&T 3B2.  Ports are underway to other machines.


     GRASS allows Army environmental planners and land managers to analyze,
store, update, model, and display landscape data quickly and easily.  Data
files can be developed for large or small geographic regions at any scale
desired within the limits of the original source documents and the storage
capacity of the hardware.  Analysis and display operations can be performed
for an entire geographic region, or for any user-defined area within this


     Version 4.0 of GRASS was completed in July 1991 and is being
distributed with source code; reference, tutorial and programmer
documentation; and an extensive sample data set.  GRASS has been installed
at dozens of military installations and most Corps Districts and Labs.
Copies are available to the general public through several distribution
sites.  For more information, see the publications "Acquiring GRASS
Software" and the "GRASS Directory," available from the GRASS Information

     Besides military installation planners, GRASS users now include Corps
Districts and Divisions, the USDA Soil Conversation Service, American
Farmland Trust, the USDI National Park Service, NASA and many
universities, commercial firms, and state and local organizations.
Electronic communication between user sites can be accomplished
over the Internet computer network.  An Interagency Steering Committee
and user group organizations in both Europe and North America have
been established to guide planning and development of future system
capabilities.  This Interagency group publishes a periodic newsletter
(GRASS CLIPPINGS) and sponsors an annual user group meeting.  The
Office of Grass Integration has recently been established to coordinate
the integration of contributed software and the distribution of
updated versions of GRASS.

     Both user and programmer training workshops for GRASS are offered
on a regular basis at many sites.  A schedule of upcoming courses and
workshops is available from the GRASS Information Center.

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