[GRASS-user] r.sun.daily ouputs

[balotti.and at gmail.com]

Hi Anna,
Here the test on NC dataset, I reduced a little bit the resolution to 
speedup computation:

 1. g.region raster=elevation res=30 -p
 2. r.resamp.interp input=elevation at PERMANENT output=dem30
 3. r.slope.aspect elevation=dem30 at PERMANENT slope=slo aspect=asp
 4. r.sun.daily -t elevation=dem30 at PERMANENT aspect=asp at PERMANENT
    slope=slo at PERMANENT start_day=91 end_day=304 glob_rad=sol_glob
    glob_rad_basename=sol nprocs=4
 5. t.rast.series input=sol at PERMANENT method=sum output=sol_sum

And the output querying on a random pixel is:

    est, nord: 636522.196262, 219573.598131
    sol_glob at PERMANENT: value: 28270.75
    sol_sum at PERMANENT: value: 1632588.35400391

The only thing that could create problem maybe is that during the 
execution of r.sun.daily I received many warnings like this (translated: 
can't rename file NULL/CELL)

    WARNING: Non riesco a rinominare il file null
    'C:\...\GRASS_data\nc_basic_spm_grass7\PERMANENT\.tmp/unknown\4860.1'
    in
    'C:\...\GRASS_data\nc_basic_spm_grass7\PERMANENT\cell_misc\sol_glob\null':
    File exists
    WARNING: Non riesco a rinominare il file cella
    'C:\...\GRASS_data\nc_basic_spm_grass7\PERMANENT\.tmp/unknown\4860.0'
    in 'C:\...\GRASS_data\nc_basic_spm_grass7\PERMANENT\fcell\sol_glob':
    File exists

Since sum by r.sun.daily is less than sum by t.rast.series, maybe the 
summed file is not properly summed and represent just the sum of the 
last days of the period?
P.S. I am on Windows with GRASS 7.2.1

---
Andrea Balotti

Il 28/09/2017 19:00, Anna Petrášová ha scritto:
> Hi,
>
>
> On Thu, Sep 28, 2017 at 5:30 AM,  <balotti.and at gmail.com> wrote:
>> Hi,
>> I am using  r.sun.daily to perform global radiation maps over a range of
>> dates but I am a little bit confused about the outputs of this module.
>> I created two outputs: the accumulated map of the whole time period and a
>> temporal dataset with all the daily maps.
>> I have tried to aggregate the daily maps in the temporal dataset with
>> t.rast.series (average and sum) supposing that one of them was the same with
>> the accumulated output of r.sun.daily but I was wrong.
>> Here the query on a pixel: the first line is the accumulated map from
>> r.sun.daily, the last two line are the aggregated maps from t.rast.series.
>> sol_glob_veg at PERMANENT: value: 24291.95
>> sol_veg_sum at PERMANENT: value: 1495683.87133789
>> sol_veg_avg at PERMANENT: value: 6989.17696886865
>>
>> My question now is which kind of accumulation perform r.sun.daily?
>> TIA
> it just sums the maps from each day, so t.rast.series with sum should
> give you the same results. I tested it in NC sample datatset and
> indeed it gave me identical results. Could you test it in the sample
> dataset and perhaps send the commands you are using?
>
> Thank you,
>
> Anna
>
>> --
>> Andrea Balotti
>>
>>
>> _______________________________________________
>> grass-user mailing list
>> grass-user at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/grass-user

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20170929/02e4da6b/attachment-0001.html>