Week 6: Gully hunting

Research:
Finally received the camera calibration reports from CDSM, so the process of orthorectifying historical aerial photography of the Eastern Cape commenced. Had a productive meeting with my supervisor, and he did me the favour of setting 14 October as the final deadline for my PhD analysis. After that it is full-time writing all the way. Spent the rest of the week orthorectifying. The bitch is that even a decent orthorectification in Erdas always has a few meters of RMS error, so some spline rubbersheeting is necessary to fit the areas of interest to exactly the right spot. Takes loooong and is booooring.

Writing:
No writing again this week. Think I will just use all my time to process imagery until 14 October, and then get to writing again.

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.

Week 3: Fragmentation

Research:
Spent largest part of the week (apart from some administrative nonsense) preparing data for stereophotogrammetry on the 2003 dataset (selecting GCP's, registering images - learning HOW to register images with fiducial marks). Performed preliminary elevation extraction and (after several accuracy tests) encountered a 3.6m vertical offset in the data - undoubtedly linked to the obscure French datum used to collect the input data - have to either subtract the average error, or find a way to convert between datums. Image size also too big for software to handle (it's never easy, is it?). Software developer promised to send updated version of software next week which will solve a lot of problems and provide a much larger amount of automation. Have decided to let everything stew until I get the new version.

Writing
Slow, as always, but getting there. Felt like I was breaking through the barrier of my own perfectionism for the first time this week. Pretty much finished the "Research Problem and Aims" section of Chapter 1. Would have liked to achieve more, but it's ok. At least I am gaining momentum.