I'm an archaeologist who has been using GIS since the early 1990's for research in Spain and the American SW. I started with MapInfo, messed with Idris a bit, used ArcView extensively, and ArcGIS a bit. I started looking into GRASS seriously about a year ago and am doing most of my work in GRASS now. I also teach courses in spatial technology for archaeology here at ASU--using GRASS this semester--and did a short-course on GRASS in archaeology at the University of Valencia last fall. (you can see my current syllabus at <http://www.public.asu.edu/~cmbarton>\)
Benjamin did a nice summary. What I can add is that GRASS is a very powerful and rich GIS and spatial analysis environment. It takes about as much effort (but no more) to learn GRASS well as any other equally powerful GIS/analysis package. Some things that are easy in ArcView are difficult in GRASS. But some things that are difficult in ArcView are easy in GRASS. GRASS's big strength is its raster modules, and the spatial analytical versatility that accompany them. However, the vector modules are pretty good also--from an analysis point of view. And they've been greatly beefed up in the new GRASS 5.7. As far as I can tell, the most complicated thing about starting to use GRASS is installing it--and this is getting easier.
Programs like ArcView and MapInfo are designed primarily to make nice, sophisticated maps. They are good on visual display of vector graphics and querying databases associated with the vector objects. GRASS is designed primarily for spatial analysis. It can also make very nice and sophisticated-looking maps, but not with the visual bells and whistles of commercial Map-making GIS packages. On the other hand, its analytical capabilities are extremely strong, and very extensible via scripting. GRASS is also a very complete package, including not only sophisticated GIS functions for raster, vector, and point data models, but a range of spatial and other statistics, multi-band image analysis, 3D (actually '2.5D') visualization, and (experimental) true 3D volumetric data models.
Many archaeologists see GIS as a new, and more sophisticated way of making maps--and especially for making alternate versions of a map showing different kinds of information or subsets of information selected by querying an associated attribute database. This is fine, but it is simply a faster and easier way to do what we've already been doing on paper and more recently with CAD and drawing packages. IMHO, the real value and power of GIS in archaeology is using it as a tool for new kinds of research on the spatial data we inherently collect but often do little with. GRASS is especially good for this. But so is ArcView/ArcGIS with the Spatial Analyst and 3D Analysts extensions installed and numerous 3rd party extensions available.
There are a couple of other reasons I like GRASS a lot. 1) From the perspective of graduate students, it is a program they can actually own--completely and legally--for the investment of time in learning it. We have a very competitive license program for ESRI products here at ASU. They are available across campus and students can purchase them at a very steep discount. However, it still will cost $300-$600 or more for a student to get a fully functional version of ArcView or ArcGIS of their own. GRASS is free. 2) GRASS is cross-platform, meaning you can use the same program no matter what computer you use (at least within a wide group of systems). 3) GRASS is international. In part because of its cost, but also because of its ability to run on multiple platforms, GRASS is widely used across the world. As someone who works in Europe, this is important. My colleagues in Spain are using it and interfacing GRASS with a powerful archaeological information system. 4) GRASS is very extensible. By using open-source tools, it interfaces with a wide variety of other, powerful open source software, including R and Gstat (is that the right spelling), ODBC and PostgreSQL databases, UNM Mapserver, and other tools. Also, shell scripting makes GRASS as programmable as ArcView (or possibly more so). 5) You can be a part of creating GRASS. This is a great opportunity for archaeologists. ESRI is notoriously difficult to contact for support, for example. While they certainly want to develop a broadly useful product, they are a huge, commercial concern and you are simply one consumer. However, you can be a part of GRASS development and create GIS tools that can benefit archaeology. Also, the other members of the GRASS development and user community are VERY responsive and helpful. To some extent, this is part of the open-source 'culture'. But it means that you can help to develop tools for archaeology instead of always be trying to adapt something designed for engineers or business analysts.
Anyway, I've probably said enough. But it has been enjoyable to find such a good GIS package that is also fun to participate in. Do look at the Neteler and Mitasova book. It is worth the cost if you can't find it at a library. Also a new version is out soon. Do get the new Spearfish demo data and work through some of the things in the book. The web site <http://grass.itc.it> is full of helpful things, even if you sometimes have to dig to find them because there is so much there. A very good place to start on the web site are the pages of the GRASS Documentation Project. You may even find yourself contributing a GRASS in archaeology primer in a couple years. Feel free to contact me if you have any archaeology-related questions about GRASS.
Un saludo cordial
Michael Barton
____________________
C. Michael Barton, Professor
School of Human Origins, Cultures, & Societies
PO Box 872402
Arizona State University
Tempe, AZ 85287-2402
USA
Phone: 480-965-6262
Fax: 480-965-7671
www: <www.public.asu.edu/~cmbarton>
From: Chet Walker <chetwalker@mail.utexas.edu>
Date: May 3, 2004 9:11:59 AM MST
To: GRASSLIST@baylor.edu
Subject: [GRASSLIST:3335] helpHello.
I am new to GRASS, GIS and UNIX . . . . as you would expect i'm having learning curve issues. I'm trying to use grass for my dissertation that entails very basic things like plotting several different types of archaeological materials as well as a bit more advanced issues such as plotting and processing geophysical data (collected with a magnetometer and conductivity meter). I have read Neteler and Mitasova's book on GRASS and consulted several online tutorials and faq's. Does any one happen to know of a tutorial or faq specifically targeted for archaeologists or perhaps know of a general introduction course on GRASS?
Thank you much,
Chet Walker
________________________________________
Chet Walker 312.857.7629
Research Assistant
Department of African and Amerindian Art
The Art Institute of Chicago--
From: Steve Sherman <ssherman@cemml.colostate.edu>
Date: May 3, 2004 10:56:07 AM MST
To: Chet Walker <chetwalker@mail.utexas.edu>, "GRASSLIST@baylor.edu" <GRASSLIST@baylor.edu>
Subject: [GRASSLIST:3336] Re: helpNot off hand, but I am in the same exact situation as you...with the exception of the dissertation part. I am new to GRASS and Linux and I am an archaeologist working on setting up a coherent and functioning system. I'm am anxious to see if anyone has a good answer to you question.
Steve
Chet Walker wrote:
Hello.
I am new to GRASS, GIS and UNIX . . . . as you would expect i'm having learning curve issues. I'm trying to use grass for my dissertation that entails very basic things like plotting several different types of archaeological materials as well as a bit more advanced issues such as plotting and processing geophysical data (collected with a magnetometer and conductivity meter). I have read Neteler and Mitasova's book on GRASS and consulted several online tutorials and faq's. Does any one happen to know of a tutorial or faq specifically targeted for archaeologists or perhaps know of a general introduction course on GRASS?
Thank you much,
Chet Walker
________________________________________
Chet Walker 312.857.7629
Research Assistant
Department of African and Amerindian Art
The Art Institute of Chicago--
Dialoguez en direct avec vos amis grâce à Yahoo! Messenger !
From: Benjamin Ducke <benducke@compuserve.de>
Date: May 3, 2004 2:03:45 PM MST
To: grasslist@baylor.edu
Subject: [GRASSLIST:3338] Re: helpHallo Chet,
I am an archaeologist and have been working with GRASS for about 6 or 7 years now.
To flatten your learning curve, I will give a (very) short summary of what
I think GRASS GIS is good for in archaeology:- GRASS has a lot of analytical functionality for raster maps (integer, i.e.
categorised data and floating points, i.e. metric measurements)
- you can easily create knew functionality by combining the inputs and outputs
of modules using shell scripts. If you know C, there is no limit to what you
can do
- GRASS up to version 5.3 is very limited when it comes to advanced vector
capabilities. This is changing for the better as work on 5.7 progresses
- GRASS has very limited CAD functionality. It's not a good choice for editing
your own vector maps
- GRASS is great for pulling in data from all sorts of different sources, rasterising
it, running your analyses and outputing it to another format for publicationNow, where would your sort of work fit into this?
Plotting and processing geophysical data is possible
through GRASS' excellent support of floating point raster maps.
You can easily:
- import measurements in regular grids from ASCII-data (r.in.ascii, or s.in.ascii, then
pass it on to e.g. s.surf.rst to create an interpolated raster)
- build nice colortables to make measurements more easily interpretable
(easiest way of doing this is by editing color tables directly. See GRASS5 programming manual)
- patch different grids together (r.patch)
- use neighbourhood functions to smooth out data
(r.neighbors although I am not aware of a dedicated low or high pass filter)
- use map-algebra to implement any other sort of filters
(r.mapcalc -- if you know the math -- I certainly don't)
- interpolate missing data points (e.g. r.surf.idw)
- handle NULL data values
- drap data over a digital terrain model (nviz)
- export to tons of raster formats (r.out.*)... plotting several types of archaeological material
Well, what sort of plots are you thinking about?
I assume you are planning to do plots of site/artefact distributions over some
sort of map data. It's easy to get the coordinates of your things
into GRASS by using s.in.ascii. You can then do very basic plots using s.display.
Look into ps.map manual pages to find out how to do more visually
pleasing stuff.
But really, if you are planning to do statistical plots,
use the GRASS-R interface to pull your data into the R statistical
programming environment (www.r-proj.org) and you have a system that
covers EVERY imaginable aspect of plotting/statistics.I have never come across a tutorial that deals with GRASS and archaeological
data, but I recommend you to download at least the spearfish dataset from
the GRASS homepage. If you know German, go to http://grass.itc.it/gdp/handbuch/
and download Markus Neteler's excellent handbookHope this will help you on your rough road to GRASS enlightenment.
Cheers,
Benjamin
On Mon, 3 May 2004 11:11:59 -0500
Chet Walker <chetwalker@mail.utexas.edu> wrote:Hello.
I am new to GRASS, GIS and UNIX . . . . as you would expect i'm
having learning curve issues. I'm trying to use grass for my
dissertation that entails very basic things like plotting several
different types of archaeological materials as well as a bit more
advanced issues such as plotting and processing geophysical data
(collected with a magnetometer and conductivity meter). I have read
Neteler and Mitasova's book on GRASS and consulted several online
tutorials and faq's. Does any one happen to know of a tutorial or
faq specifically targeted for archaeologists or perhaps know of a
general introduction course on GRASS?Thank you much,
Chet Walker
________________________________________
Chet Walker 312.857.7629
Research Assistant
Department of African and Amerindian Art
The Art Institute of Chicago
