topic Solar Radiation output in ArcGIS Spatial Analyst Questions

Solar Radiation output

GregoryLipps — Thu, 14 Apr 2011 12:02:23 GMT

I just finished running the area solar radiation tool for a full year on a 10m DEM. Looks good, but I'm having trouble understanding the format of the results. The main output is displayed as a 3-band raster (RBG). I can change this to display stretched format and thereby get a single value for each pixel. When I examine the file though (expand in the catalog), I find that it contains 12 individual bands, numbered sequentially.

Web Help tells me:
"the default output format is an ESRI GRID stack containing multiple bands that correspond to the radiation or duration values for each time interval"

Questions:
1) What is the stretched raster value? Mean of all twelve months? Sum?
2) I'd like to create an attribute table for further analysis, but can't do this for a multi-band raster. Suggestions?

Thanks in advance for your help,

Greg

Re: Solar Radiation output

MarkEllis — Thu, 09 Jun 2011 18:04:41 GMT

It's been a while since I used the solar tools, but if I recall...

Each of the 12 layers represents a month; display one and save as a layer file.

Load the layer file and modify the values in the raster display to include the min and max of the range of all 12 months - this is where my memory might be hazy - which are found in the 3 band RGB. By manipulating the ranges (Layer properties symbology) to stretch from min to max, you can group them into a color scheme appropriate to your data needs. Save this layer file.

Because all values are covered in this layer file, it can be applied to all 12 months. Each is based on one legend and thus display consistently. As for an attribute table, you would need to convert this (or all 12 months if you need them as separate data sets) with spatial analysis to an integer grid.