Albert Einstein
Something I strive to do on a daily basis…
Thought for the day
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GIS, digital elevation models, and free data
GIS, DEM and data
As part of my burgeoning interest in the use of GIS to supplement the visualisation of health-related data, this post is about some of the resources that I found during a very late night spent surfing on the iPad into the wee hours.
It may interest you to know that this post is being dictated into my new PC, well rebuilt PC, using my Dragon NaturallySpeaking software. I also have a cold which means that this is not the most efficient way of getting text into the posting but whatever let’s go for it.
One of the things I’ve been looking to do is create ESRI shape files of elevation built from freely available datasets without any restrictions against commercial use. Not the easiest proposition as understandably, the open source community is keen to protect the exploitation of their data by commercial organisations.
In the investigations that followed last night, I’m indebted to two fellow bloggers whose pages have provided hugely useful links to free and open source datasets and to the tools required to manipulate them.
Terrainmap and Robin Wilson’s blog, particularly the free GIS dataset page.
Although I had been peripherally aware of NaturalEarth data, this little surfing session really cemented the utility of using this vector-based data as a replacement for commercially licensed data from folks like ESRI or CollinsBartholomew.
The gold standard of digital elevation models data is that hosted by CGIAR but this has restriction against commercial use. It is based on NASA data from the space shuttle remote sensing mission in 2003 with postprocessing but for the purposes that I need, namely rough calculations of the limits of malaria transmission in order to create some customised shape files, the original NASA data will likely suffice or it may in fact be possible to do what I need with less specific data. I’ll probably end up using the Earth Explorer interface to select and download the required data.
I also looked at the USGS GTOPO30 data but think it might lack a little resolution for what I need.
A derivation/enhancement of the STRM data is provided by the DeMontford University ACE2 project.
Software for manipulating the data:
(shamelessly “borrowed” from terrainmap)
Free Software
Some good free applications that every terrain modeler should have in their toolkit:
Google Earth The former heavyweight champion of GIS applications. Makes all the rest virtually obsolete. (can’t really use this in a commercial environment without a PRO licence)
World Wind The former heavyweight champion of GIS applications. (does exactly what it says on the tin – looks like I might be using this)
3DEM The (former) best application for producing overlays. Great 3D renderings.
MicroDem The best application for merging DEMs. Reads a fairly wide variety of formats. OK for 3D rendering and overlays.
Terragen The best application for photo realistic terrain renderings. Reads only its own .ter format. (Several converters offered on this site).
Also worth considering is DEM2topo which I found on Leszek Pawlowicz’s Free Geography Tools Blog.
Professors Encode with E. Coli News The Harvard Crimson
Professors Encode with E. Coli News The Harvard Crimson.
Well, now I’ve heard it all – colour coded bacteria as the ultimate encryption. Just don’t eat the message to stop it from being uncovered – there’s a pretty good chance that either:
1. it won’t agree with you and you’ll get sick or;
2. It’ll colonise your gut and you’ll never be rid of the secret message…
GIS Part 0
In tracking disease and other crises, I occasionally come across a really good example of using interactive services to promote information.
This is one of those examples from an NGO I have a lot of time for:
Oxfam Food Prices
I’m working on developing my GIS skills and will post more on this subject in the coming days/weeks as I get to grips with some of the Open Source software that is out there.
Faster iMac
Treated the beast to some new RAM…
8Gb is much more useful than 2Gb…
The little machine in the playroom now has twice the memory of my desktop and is a good deal quieter… perhaps there is a lesson in this for me… hmmm <note to self – do not get tempted by the new Mac mini…>
Those Thunderbolt ports and the ability to link it to a NAS/SAN box means that you don’t need masses of onboard storage… I really have become an Apple Fan – woe is me for I am undone… 
Geek-out
In a bid for world domination or at least domination over my desk I bought myself a new monitor stand to go from this…
to this:
Thanks to this:
Thankfully I bought it before the jump in price…
