I'm not an expert in GIS, I learnt it recently, and I'm trying to improve my skills.
I'm trying to calculate the loss of solar radiation at a specific point due to surrounding topography. I'm basically trying to understand how to do what is explained on ArcGIS help website: http://desktop.arcgis.com/en/arcmap/latest/tools/spatial-analyst-toolbox/modeling-solar-radiation.htm
I have also found this paper that achieves exactly what I would like to do: http://www.esri.com/news/arcuser/0309/files/solar.pdf
My issue is that I don't understand the process.
So far, I have managed to:
- Generate a viewshed (from a point and a DEM): I've got a raster that shows me what area of the sky is not visible (a mountain range at the horizon).
- Generate a skymap for diffuse radiation calculation: I've got a raster with time of the year and time of the day.
- Generate a sunmap for the period I want to know, for direct radiation calculation.
In theory, I understand I have to overlay my viewshed raster with my skymap. The ratio will show me the loss of diffused radiation. Same for the sunmap for direct radiation.
But I have no idea how to do it. ArcGIS help about equations is too complicated for me, I would like to know how to do it in ArcGIS. I don't understand the values of my generated rasters, and I'm not sure they are sufficient to calculate what I want.
I would also like to be precise that I don't intend to calculate radiation for an area yet. Only for a point now, and the only outcome I want is a loss ratio for both diffuse and direct radiation.
Other question: once I have done it, how can I add scales and axis to the graph generated by ArcGIS? Is there a way to do it with ArcMap or it's a Photoshop thing?