One purpose of attempting SDI-EA has been (optimistically?) to test how feasible SDI technologies are outside OECD-type countries, using the UN's own capacities to augment local infrastructure where needs be. Over the last two week has been an exercise in frustrated realization of what the limits can be like.
It all started with a flurry of requests for data and land cover change analysis - one from the GEF evaluation office, the second from a UNEP study of refugee camps, the third from researchers in land use conflict avoidance in Kenya and Tanzania. All good stuff and, thinks I, a good chance to test some of my theories against cold, hard reality.
All these requesters, by thge way, were suffering from the delusion that UNEP/GRID still acted as some sort of massive data archive that would have the necessary data on hand. Alas, no. That's a business model that went the way of the dodo many years ago. Frustration #1 was discovering that our own backyard is in desperate need of a cleanup - the Landsat data and stuff that I know NASA delivered to us years ago is nowhere to be found. Or, more accurately, no-one knows where to find it. Oh dear.
Anyway, this is the age of the internet and postals and all we need do is know how to find the data and use our satellite capacity to pipe it into Kenya for our clients, right? Theory says that we can be clever and use on-line services to slice out justthe bits of the images for relevant study areas - a few megabytes rather than 10's or hundreds of them, smart use of limited bandwidth, more readily accesible to users in developing countries and so on.
Second frustration: NASA's geobrain (http://geobrain.laits.gmu.edu/) usually provides a neat web coverage service whereby you designate your are of interest and it goes off, interrogates the LAITS catalogues and comes back with thumbnails of the available scenes; you make your selection and it then goes to the WCS, excises the footprint you've selected and send a nicely bundled tar package your way in a matter of minutes. What's wrong with this picture? Just the fact that the services is off the air this week. Sigh
So now I'm using sites that only deliver full scenes, such as the Global Land Cover Facility's Earth Science Data Interface (http://glcfapp.umiacs.umd.edu:8080/esdi/index.jsp). Obviously a much greater demand on our satellite link but worth a try. Except for the fact that the link has been slow and flakey and up and down all week - what might otherwise be an easy 20 minute 16 Mb transfer sometimes taking half a day. Sigh. Not the sort of reliable service we'd like to offer our partners.
Glad I didn't offer to mortgage the house as guarantee of being able to deliver on the requests made to us. Maybe things will be better next week. It's still not a great advertisement for SDI, is it?
------------------------ 24 Hours later ---------------------------
Well, things have picked up a bit, and last night I actually managed to pull down 4 MMS scenes and a full TM set, a total of about 350 Mb - not a huge volume of data in these days of streaming media but significant in this part of the world. Now, if only GeoBrain start behaving itself....
--------------- ... and 24 Hours after that? ----------------------
Well, some hacks and work-arounds later, I've managed to pull down about 10 Thematic Mapper and half a dozen MSS scenes, a total of about 2 gigabytes of compressed data moved as scheduled downloads overnight while UNEP's bandwidth is mostly unused. Frustration the Thjird:As it turns out, the usefulness of all this data was pretty limited, usually because the change signals being sought were not significant at the resolution of the Landsat data. This is where having had Geobrain working earlier would have really helped: at least the limitations of the images would have been apparent earlier and more quickly, and the requesters could have adapted their expectations.
Now, this gets me thinking: why am I downloading data from Maryland anyway? What if the Regional Centre for Mapping Resource Development here in Nairobi could bring its Landsat archive on-line, a sort of Geobrain East Africa? Must have a word with my friend Byron about that possibility...