[GRASS-user] Rsun problems

[Silvia Franceschi]

Thanks Hamish,
very king.

Silvia

PS: how do you use r.series? I thought to use r.mapcalc



Hamish wrote:
> Silvia Franceschi wrote:
>   
>> I am trying to use r.sun and have some problems understanding the
>> results. If I want the total irradiation in a specified day then I
>> have to select  the option 2. In this case I obtain the following
>> maps: - beam_rad: irradiation raster file
>> - insol_time: insolation raster map
>> - diff_rad: irradiation raster map
>> - refl_rad: irradiation raster map
>>
>> So I don't understand a few things... :-(
>>     
> ..
>   
>> - where does GRASS save the irradiation raster file?
>>     
>
> it's not one output file, it's a raster map named whatever you gave the
> beam_rad option. see below.
>
>   
>> - what is the difference between the diff_rad irradiation raster map
>> and the refl_rad irradiation raster map.
>>     
>
> one is diffuse light (think cloud scatter), the other reflected light
> (glare bouncing off ground hitting hillside??).
>
>
>   
>> - I noticed that I have a raster map created with the name of the 
>> beam_rad "file", so I think in this case GRASS makes a raster and not
>> a file, but what do these values means?
>>     
>
> yes, beam_rad mades a raster map, not some data file. This is already
> changed in the development source code.
>
> mode 2 units are Wh.m-2.day-1.  Watt-hours per meter^2 per day.
>
>   
>> - which of these maps created whit the command gives to me the total 
>> radiation for the day? maybe I have to sum some of them but I don't 
>> understand which of them to take into account.
>>     
>
> total = beam + diffuse + reflected
> (add with r.series)
>
>
> Hamish
>
>
>