Wednesday, 23 August 2017

MSL Part 10: Timaru

This is the part that was going to be quite tricky to do because the tracks needed to be traced from the much sharper and clearer LINZ aerial photography of Timaru (which has a resolution of 0.075 metres, much better than Google Earth has ever had of the area). The problem was how to get the aerial coverage easily into place to be traced with GE.

Well fortunately with a bit of work I was able to download the aerial photos from the LDS site and then open them in Qgis, as they can be georeferenced, which means that along with each source image, data files are also included that tell the software where to locate each photo on the map canvas. This makes the job of aligning the photos in the right place much simpler, in fact completely automatic.

So for the very first time ever (July 2016) I have traced over aerial footage directly in Qgis to make the map, this time the Timaru yards. Since Linz has a lot of aerial coverage from around the country and most of it is of high quality, I am expecting to make a lot more use of this capability in future. The maps that follow are the result of this work.