A while ago I did a neighbourhood roof orientation survey for solar panel deployment, by visually checking each roof and marking individually whether they were south or almost south-facing.
As this is very time-consuming, I would like to find a way to automate this, but don't know how this would be possible by merely analysing roof shadows.
I can script a little but have never written any plug-ins.
What other elements do I need to include?
We are on a very low budget, so seek any suggestions how to do this using open source tools.
Best Answer
Is is possible that LIDAR has been flown recently in the area? You can extract buildings this way... LIDAR would most likely be too expensive to fly yourself, probably at least 8-12k for an area that size.
http://knol.google.com/k/aerial-extraction-of-roof-surfaces-for-solar-analysis#
Found that article, may be of some help.