Abstract:
GRASSLinks is an interactive, real-time Web GIS application developed by REGIS based on the U.S. Army Core of Engineer's GRASS GIS software. GRASSLinks allows for sophisticated GIS functionality, such as display, query, reclass, overlay, and buffer, to geospatial data in GRASS format via the use of a World Wide Web browser, such as Netscape. In order to be able to use GRASSLinks to provide Web ... access to data, that data must first be in a GRASS file format and all data must be in the same projection and coordinate system.
GRASSLinks seeks to serve two communities of geodata users: those who do not have GIS capabilities and those who do. The first group is comprised of users with access to the internet, but who do not have their own GIS capabilities. Mosaic is available on most platforms and is currently in the public domain. A Mosaic-based "point and click" interface ensures that users need not know any of the specific commands normally required to access a GIS.
The second group served by GRASSLinks includes land use planning and management agencies. Land use planning decisions frequently require the cooperation of multiple agencies. Or, different agencies may need to use the same information for their own purposes. GRASSLinks can be an important part of creating a distributed database network. Historically, each agency would have its own database, and then continually maintain their own data as well as data obtained from other sources. A new model of data sharing would be for each agency to maintain data for which they are responsible, and then access other data over the network as needed. This model can be applied to non-governmental organizations, research groups schools, or commerical entities.
Tools included in GRASSLinks:
1) Map display: images are created of raster, vector, and sites data layers.
a) The vector and sites drawing colors, map region, and image resolution of the image can be specified.
b) Zoom in, zoom out, or pan across an image to create new images which can also be navigated ad infinitum.
c) query of map display -- the value of the displayed raster data and the coordinates of the selected point are queried by clicking with the mouse on the image
2) Aerial photography display: A map of the area depicts the location of aerial photo stations. Clicking on a station brings up the appropriate photograph.
3) Metadata display: the information describing the map layers, their source, dates, accuracy, etc., is available for the data layers.
4) Area calculations: The Areal extent of mapped categories, or the overlap of categories between two maps is calculated (e.g., wetlands acreage by county)
5) Reaggregation: categories of a data layer can be aggregated together to create a new map (e.g., a map of more general wetland types).
6) Buffering: Successive bands of known width around specified map categories, create a new map showing proximity to features (e.g., a riparian zone, or a buffer around drinking wells).
7) Combining maps: A new map can be produced that shows areas of overlap between categories in different maps (e.g., existing wetlands within areas zoned for development).
8) Data layer transfer: the GRASS format data layer can be downloaded for personal use.
Description:
GRASS Data Files available via GRASSLinks
Service Citation
Originators:
Susan M. Huse
Title:
GRASSLinks: The Public Access GIS
Release_Date:
1998-01-01
Provider:
Oregon State University
Edition:
3.2
URL:
http://ippc2.orst.edu/glinks/
Quality
REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
Access Constraints
GRASSLinks is a perl script and requires local access to perl. GRASSLinks has been tested under Digital Unix 4.0. It should run on any UNIX system or any system that has Perl 4.x or 5.x installed (though it will probably need more tweaking on a non-Unix system that what is detailed herein). You must have the software GRASS accessible from the same server that is ... running GRASSLinks and you must have some existing GRASS raster, vector and sites files. You must have a web htdocs directory in which to locate GRASSLinks html files and helper files. You must have the ability to run cgi scripts on your web server. You will probably need access to super-user status on your system or the person with this status. You will need to install the free netpbm/pbmplus ppm programs which can be downloaded off the web. GRASSLinks utilizes public domain software, GRASS, created by the US Army Corps of Engineers. We assume that anyone installing GRASSLinks already has experience using GRASS.
Use Constraints
Grasslinks 3.1 Copyright (c) 1998 The Regents of the University of California (Regents). Created by Patricia Frontiera, Susan Huse, James Ganong, and Kenn Gardels, Center for Environmental Design Research, University of California, Berkeley. GRASSLinks 3.1 is based on a work created by Susan Huse at the University of California, Berkeley.
Redistribution ... and use of GRASSLinks 3.1 in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1.Redistributions of source code (with or without modification) must retain the above copyright notice, this list of conditions and the following disclaimer. 2.Redistributions in binary form (with or without modification) must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Name:
PAUL
JEPSON
Phone:
(541) 737-9082
Fax:
(541) 737-3080
Email:
jepsonp at science.oregonstate.edu
Contact Address:
Director (IPPC) & Professor of Entomology
Oregon State University City:
Corvallis
Province or State:
Oregon
Postal Code:
97331-4501
Country:
USA
Distribution Media
Distribution_Media:
Online
Fees:
No fees
Personnel
TYLER
B.
STEVENS Role:
SERF AUTHOR
Phone:
(301) 614-6898
Fax:
301-614-5268
Email:
Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory City:
Greenbelt
Province or State:
MD
Postal Code:
20771
Country:
USA
Creation and Review Dates
SERF Creation Date:
2003-01-08
SERF Last Revision Date:
2006-05-18
Links
