The Atlas Mountains views introduced in the previous post are my first use of the SRTM high resolution data in 3d rendering. Here a higher resolution crop for comparison (first is the 1 arc second data, second 3 arc seconds):
This well illustrates what i have already written in my analysis – that the resolution gain from the new data is fairly small. There is a lot of noise coming with the higher resolution grid – not as much as with ASTER GDEM but still quite visible.
It is not so easy to quantify the actual resolution but various claims you can read on the internet now with triple resolution, nine times as much data, 30 meter elevation data etc. are exaggerated. Without making a specific quantitative claim it is fair to say that the gain from the old 3 arc seconds data to the newly released data is much less than from the new data to what would be possible in principle based on a 1 arc second grid. It is a bit like with the Megapixel inflation of digital cameras…
The noise can also be a problem in map rendering since it can severely affect readability of a map. When you generate relief shading or contour lines strait from the raw relief data this will be dominated by the small size features which is largely noise in case of the high resolution SRTM data. With proper processing the data can however be used for a better articulated depiction of relief.