Mapping on the cheap
Posted 05 November 2005 - 02:37 AM
Of course I really don't know very much about map-apps (mapping applications) and have only limited experience, so I need to go about selecting software in a pretty systematic fashion.
My model for mapmaking involves (1) selecting base vector files (and also raster files for some maps), (2) using a map-app to project the files and select and edit the attributes to be included, and perhaps add some kinds of features (such as range arcs or other metric features), and (3) using Adobe Illustrator and in some cases Photoshop to do the bulk of the editing and preparation for publication. I am sure this is oversimplified and it may be wrong in some respects -- I invite comment or criticism.
After searching through CartoTalk and elsewhere I have come up with a short list of map-apps of possible interest for my purposes, including:
Generic Mapping Tools (GMT) <http://gmt.soest.hawaii.edu/>, a powerful, widely-used, free command-driven map-app.
GRASS GIS <http://ludique.u-bou...grass/index.php>, a free GIS often mentioned in conjunction with GMT. I'm not entirely sure at this point what the division of labor is between them.
Quantum GIS (QGIS) <http://www.qgis.org/>, another free GIS, but featuring a GUI. I know little of it yet.
DIVA-GIS <http://www.diva-gis.org/>, yet another free GIS. I know little about it yet except that it was originally developed by people interested in biodiversity issues.
MicroCAM <http://www.ilstu.edu/microcam/>, a free, radically morphed version of CAM -- the CIA mapping program that in mainframe/batch form was long the standard of computer mapping. Now it is a Windows program tailored for instructional purposes. Strictly vector. Limited input formats.
Manifold 6.50 <http://www.manifold.net/>, at $245 (USD), the cheapest reasonably fully-featured commercial GIS that I found. Claims a very rich feature set. But has a restrictive copy-protection scheme that looks like trouble to me.
Global Mapper <http://www.globalmapper.com/>, a $249 (USD) commercial map-app.
Of course there are many others which do not fit my definition of affordability (as Manifold and Global Mapper do marginally) -- on up to thousands of dollars per seat. There are also Versamap and AGIS, which I already have and know will not meet many of my needs very well.
In the absence of better information, I plan to work my way down the list until I decide that I have found some thing(s) good enough to make further search not worth my while. Hopefully, this will come before I get to the list's end, preferably while I'm still in the free products.
I'll report on what I find for the benefit of others similarly in the dark, and welcome any inputs anyone cares to offer.
Posted 05 November 2005 - 07:08 AM
GRASS is command line as you correctly indicated but is also best run native in Linux or MAC OSX. I would spend some money before trying to run it under windows, if you already run a Linux box and are comfortable with the interface it may be the best choice for you. Not sure on its export functionality and how easy it is to get vector artwork into Illustrator.
I've been a Manifold user for almost 5 years now. I've been through 2 PCs and a couple of system re-installs due to hardware failures in that time. Licensing restrictions have never been an issue for me and I have heard of very few folks who have had problems with this. In fact Manifold is very generous, it will let you install their software on both a PC and a Laptop if you own both. I know of few software manufacturers that "officially" let you do this.
I've never used the other software apps you mentioned. I demo-ed Global Mapper a few years back. It seemed very good at what it did but in the end I decided it was too expensive for its limited functions, for the same price Manifold is a much better investment.
Posted 05 November 2005 - 01:36 PM
2. projecting data:
Raster and vector coordinate system transformation can be done with the GDAL tools ogr2ogr and gdalwarp. I have a couple examples of how is can be done here. If you are only interested in projecting points, the PROJ4 library and commands will do all of that for you- examples here.
1. and 2. selecting maps, editing attributes, adding features
This can all be done in GRASS, however the vector digitization tools are a bit dated. Traditionally GRASS has been a command line tool. Over the last 2 years considerable work has been done on a GUI for GRASS. Alternatively, Qgis can be used as a clean, modern front-end to GRASS with new and improved vector digitizatoin tools. I haven't tried this approach yet, but I have heard good things about it on the various mailing lists. The vector handling capabilities of GRASS are greatly enhanced if you make use of a database management system like PostgreSQL, MySQL or even SQLITE. GRASS has the ability to output PostScript, but I have found it a bit limited. Since GRASS is more of an analysis toolkit, its not surprising that there is limited support for cartographic output. I have put together some notes on getting GRASS running on a linux system here.
This is where GMT comes in. Raster and vector data can be easily exported from GRASS (via GDAL) into formats that GMT can understand. Once you have your data exported from GRASS, you an use GMT to produce [E]PS output files of any size: ready for printing or further work in something like Illustrator. And while not a very beautifl map, here is an example of using GMT in conjunction with GRASS. I have posted a slightly better looking map here in cartotalk.
I am currently working with some of the GRASS developers to make it easier to interface GRASS to GMT, i.e. use GMT as the engine for print quality map production. I expect that we will have a working framework ready in the next couple of weeks.
Attached is a figure that I made about 6 months ago, exploring the possible connections between GRASS and GMT.
Posted 07 November 2005 - 01:07 AM
Although the first release seems to have come this year, the origins of it go back to the late 1990s and a dissertation: Olaf Conrad, Ableitung hydrologisch relevanter Reliefparameter aus einem Digitalen Geländemodell (Göttingen: Institut für Geographie der Georg-August-Universität zu Göttingen, 1998). In the absence of a suitable 'Digitalen Geländemodell,' apparently, Conrad developed his own, which he christened DiGeM. <http://www.geogr.uni.../pg/saga/digem/>
SAGA is a second-generation system, described as follows <http://www.geogr.uni...nt=contsaga.php>:
SAGA (System for Automated Geoscientific Analyses) is a hybrid GIS software. The first objective of SAGA is to give (geo-)scientists an effective but easy learnable platform for the implementation of geoscientific methods, which is achieved by SAGA's unique Application Programming Interface (API). The second is to make these methods accessible in a user friendly way. This is mainly done by the Graphical User Interface (GUI). Together this results in SAGA's true strength: a fast growing set of geoscientifc methods, bundled in exchangeable Module Libraries.
After only a few hours of exploring it I scarcely qualify as an expert, but so far it looks as if it will do very well indeed. Of course I take it for granted that no matter what GIS I use, for publication-quality maps I will have to do much of the work in Illustrator and/or Photoshop.
The present version of SAGA is only compiled for Windows. A new release now in beta, however, is desiged for cross-platform application, including Mac and Linux.
A few notes on other systems may be helpful to some others. As noted by others, GRASS and GMT are both really UNIX-oriented systems. It is possible to run them under Windows by various expedients, but it seems like a kluge I need not bother with. QGIS is a native Windows app and has a good GUI, but in its present form seems fairly short in capability. DIVA is targeted at biodiversity analysis, which did not seem a particularly promising fit for my needs. While I have not fully expolored these options I feel pretty certain that they offer little or nothing I need that is not available in SAGA.
Most of us are used to commercial s/w and feel a bit unsure about how well freeware will serve us. These programs, however, are sharply different from traditional freeware. All are organized, cooperative efforts produced by people who have strong professional reasons to make a good job of it. There seems to have been a very distinct trend toward "slick" products, not the cranky, idiosyncratic, obscure programs many of us associate with academic s/w. And all have manuals and/or tutorials as well as active user forums, where people seem quite willing to help the new boys.
If SAGA turns out to serve my needs as I expect, I figure I can make a good donation of money to the project (since there seems lilttle prospect that I will contribute anything in kind to it) and still be money ahead.
Posted 07 November 2005 - 11:50 AM
My paintings (...and no, my Avatar is Vera by Fredrick Varley)
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