On Thu, Apr 28, 2016 at 1:48 PM, Ben Hur Pintor <[email protected]> wrote: > Thanks for the response. I've seen a lot of literature and uses of r.sun > which is one of the reasons why I chose it as my model aside from the fact > that it's open-source. However, most of the uses are European setting which > I understand since r.sun is based on ESRA. I wanted to see how well r.sun > performs in a more tropical setting and from my initial findings and > studies, it seems to be doing pretty well. > > r.sun and r.sunmask both seem to use the SOLPOS algorithm, the SPA > (http://www.nrel.gov/docs/fy08osti/34302.pdf) is a more recent solar > positioning algorithm by NREL and is much more precise than SOLPOS so I > wondered if using SPA instead of SOLPOS might provide better results.
Long time back I added the SOLPOS support in r.sunmask. Do you have a pointer to the SPA source code? Because implementing it from a 40 pages PDF is expensive :-) > With regards to using LiDAR-derived raster data, my machine can actually > handle it but it just takes a lot of time. I have a 1m resolution LiDAR of a > 500 sq km area (~5GB) and it really just takes a lot of time and disk space > -- specially for horizon rasters. I'm looking into parallel processing to > remedy this issue. You may consider to tile the data (r.tile) with sufficient overlap, then process these tiles in parallel. > Lastly, I would also like to go into 3D urban solar energy modelling which > is why I asked about v.sun or any other attempts in GRASS to develop a model > for solar radiation received by 3D objects (i.e. buildings including facades > and roofs). Yes, here some pointers: Hofierka and Zlocha, 2012 A New 3-D Solar Radiation Model for 3-D City Models http://onlinelibrary.wiley.com/doi/10.1111/j.1467-9671.2012.01337.x/abstract 3-D city modeling for sustainable energy applications http://web.science.upjs.sk/hofierka/projekty/vega2_results.html Hope this helps for a start, Markus -- Markus Neteler http://www.mundialis.de - free data with free software http://grass.osgeo.org http://courses.neteler.org/blog _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
