Computing, GIS and Archaeology in the UK

This is an idea that seems to come up every so often- what GIS programmes can you run from a USB stick. Well it appears that the list has just got longer. I’m probably the last person to realise it’s possible to do this, but I was really pleased to see that both GRASS and PostgreSQL can now be run from a USB stick, along with QGIS, XAMPP (inc Mapserver, OpenLayers, Tilecache), and FWTools.

Before I go any further, I should state that my aims for creating a portable GIS are not so much having a production GIS setup on a stick, because obviously performance and storage are an issue, but it might be useful for demonstration purposes, and I do feel as if the take up of these opensource tools might be more if they were easier to install and came in one handy package. So what I really want to achieve is a single portable package, probably a zip-file, that can be downloaded and unzipped onto a Window pc (they can learn about the joys of linux once we’ve won them over to the basic concept of opensource). No separate downloads, long installation and configuration processes, just a zip file. I do also like having portable packages on my main computer, as if it breaks it’s a lot easier to reconstruct the setup!

The light-bulb moment for me was when Leif told me that he had seen GRASS working on a USB stick using Msys at the recent CAA conference in Berlin. This intrigued me, so I looked into it and it works quite nicely- as long as you use the same drive letter to mount your USB stick to all the time. I still have to figure out how to figure out the drive letter and change the paths, probably in a batch file. Put simply, you download Mingw and Msys onto the stick, follow the instructions for downloading GRASS, edit the install_grass.bat file to change the drive letters, and off it goes.

PostgreSQL was something I had looked into a while ago, been told it wasn’t possible, and given up on. However, the recent 8.2 release appears to have dropped the requirement for a dedicated non-administrative user to run it. If you download the windows binaries, without the installer, you can set it up whilst logged on as the standard user. When you next run PostgreSQL from a different machine, you just have to use the same username as on your installation pc, regardless of whether that user exists on the pc that you are currently using. Once you have PostgreSQL installed, you can install Postgis into the same directory.

Currently there are a couple of gotchas. Most of these programmes require you to set environment variables, which might not be allowed on the particular pc that you are using, and require some command line experience. I still haven’t quite figured out how to get GRASS to work if I change the drive letter. Also, PostgreSQL does indeed run very slowly on a USB stick. And, I haven’t fully explored this to make sure there isn’t a hidden trap somewhere, or security holes that might be exploited. Having said that, if you want a package that can be unzipped onto a pc with a minimum of fuss then I think it’s almost there.

What’s next? Documentation, as always, and the permission of the various programmers that it’s OK to do this. Oh, and comments please, on what else we might include, or words of wisdom if you’ve already tried it.

If you need almost-free contour data, for broad-scale maps showing the terrain of an area, and you live in the UK, then the Scottish Mountaineering Club have kindly provided data in Garmin IMG format on their website. To convert this into other GIS formats, then there is a programme called GPSMapEdit, which is shareware but quite useful. Paying for the software unlocks an option to convert to mapinfo, and from there the world of GIS is your proverbial oyster.

On my new tips and tricks page, I have included some step by step instructions for getting this data properly projected in British National Grid format in ArcMap, and how to interpret the results (not as simple as it sounds).

Having rearranged things at Archaeogeek Towers I appear to have lost the page where I showed how to use the data once you’ve got it into GPSMapEdit, so I will try and redress that asap.

Now, this data is not error free, as the authors freely admit, but it’s good for nice relief maps showing the basic terrain of an area. If anyone knows of other methods of getting this kind of data, then I’d love to here about it- leave me a comment!

James Fee’s Spatially Adjusted Blog has a mighty useful post on it today- an updated list of his feeds, including GIS Blogs, ESRI-specific Blogs and other GIS Sites. Most of these are aggregated in Planet Geospatial (probably the most useful GIS Link you’ll ever need) but some are not. Best of all, he’s included the opml files for easy rss integration.

On this page I’m going to list the books and papers that I find most useful.

Archaeology Related Texts:

Digital Archaeology by Thomas L Evans and Patrick Daly

Actually, this is a new book that I haven’t had chance to read yet, but Tom used to be the Head of Geomatics at Oxford Archaeology and did a lot to move the department forward so I’m sure it will be good (and I’ll be buying it myself for sure).

Spatial Technology and Archaeology by David Wheatley and Mark Gillings

This is one of those texts that anyone who is serious about doing good quality geospatial analysis with archaeological data should read.

Web-Based GIS:

Web Mapping Illustrated by Tyler Mitchell

For an outline of the whole area of web-based mapping, this is hard to beat. Amongst other things, it gives you the clearest set of instructions for installing PostGres/PostGIS that I’ve seen, and a very useful glossary of MapServer commands.