Week 10: Wrap it up

Research:

Refined the shadow altimetry to work even when using oblique photos. Performed a multiple-scale DEM subtraction on my stereo DEM's to view the effect of resolution on volume calculations. Re-tested the accuracy of my 2006 and 2008 DEM's (correctly this time), and was delighted to find that the accuracy was even better that I thought - very nice. And that, as they say, is that! :-) The end of my analyses. Woohoo!

Writing:

Spent some time building a workable structure for the thesis - something that would flow logically while presenting the research in a scientifically sound way (thanks to Nicolas for suggesting the split into 3 parts, makes much more sense that way). Wasted a little time on this, for fear of the unkown that lies beyond :-)

At this point there are seven weeks left for me on Réunion, and I aim to write as much as possible of the actual science while I am here. I will have a month and a half in South Africa in which I can edit and refine and rewrite everything to make it flow, but it is imperative that I get as much as possible on paper before then. Wish me luck. Two-Ten has dwindled to One-Forty Two (!)

Week 7: Chasing cars

Research:
Finished the orthorectification of 1953 aerial photos in the three key areas defined in South Africa for the mapping of gully extension. Having done that, I realized that I had no real plan as to do with them - much like a dog having finally caught the car he was chasing. Experimented with ways to extract gully characteristics stereographically. Weekly meeting with supervisor was good, but more focussed on external data sources etc. Performed some validation of the 2008 DEM I constructed using stereophotogrammetry by comparing it to a LIDAR campaign, and the results are encouraging (except of course that it took the LIDAR a few seconds to do what took me a month). Anywaaay.....

Writing:
Still postponed until next week, when the last of my analyses will be finished.

Week 5: Photogrammetry

Research:
The principal goal of the week was to build a stereo DEM of an area north of Matatiele. First try gave dubious results because I didn't initialize the stereo pair with the true calibration parameters. Phoned the Chief Directorate: Surveys & Mappings in Cape Town, and the promised to send me the calibration reports, which of course, they didn't. Even after repeated email requests. Angry about that.

So the rest of the week kinda slowed down from there. Prepared for, and performed more aerial photography of Rivieres de Galets from a small aircraft. The planning paid off, and the images are beautiful and at a very acceptable resolution. Further, identified areas of gully erosion in the South African study area that will be studied using time-series analysis. Also had a very positive meeting with my supervisor, and we decided on a list of candidates for my PhD jury. Exciting stuff.

Writing:
Again, zip. Not good.

Week 4: Riviere des Remparts

Research
This week was dedicated primarily to starting (and finishing!) a section of my PhD that deals with erosion in Riviere des Remparts on the south east coast. Lots of back-&-forthing between conflicting projections & vertical coordinate systems, but finally some interesting results. Also tackled a enormous box filled with (what I thought would be) an eternity of manual data entry from company reports - turns out only two or three reports deal with Riviere des Remparts. Suspect somebody stole a key report, but no way to prove it... meh.

Identified one (of probably a few) case study areas for gully erosion in the Eastern Cape. Started consolidating the historical aerial photography for that area. Mosaicked the 2001 images to serve as reference set and constructed a 20m DEM from 1:50 000 contours.

Did a test-flight of the new version of the Poivilliers software and it works like a charm. Communication with the developer also ironed out some zooming issues. Next week will see a brand spanking new DEM of Matatiele as it looked in 1955...

Writing
Zip.