[GRASS-dev] compile 6S library in GRASS

[Roberto Marzocchi]

Il giorno mer 27 giu 2018 alle ore 15:25 Markus Metz <
markus.metz.giswork a gmail.com> ha scritto:

>
>
> On Wed, Jun 27, 2018 at 3:06 PM, Roberta Fagandini <
> robifagandini a gmail.com> wrote:
> >
> >
> >
> > 2018-06-27 14:24 GMT+02:00 Markus Metz <markus.metz.giswork a gmail.com>:
> >>
> >>
> >>
> >> On Wed, Jun 27, 2018 at 2:16 PM, Roberta Fagandini <
> robifagandini a gmail.com> wrote:
> >> >
> >> > I'm trying to create an automatic procedure to retrieve all the input
> parameters for the control file of i.atcorr.
> >> > I need py6S because I want to automatically read and compute AOT at
> 550nm from an AERONET file.
> >>
> >> With AOT you mean aerosol optical thickness right? This is user input
> to i.atcorr. There are various sources for AOT at 550nm, e.g. MODIS.
> >
> >
> > Right!
> >
> >>
> >>
> >>
> >>
> >> Anyway, it is probably much easier to to write your own routine to read
> the AERONET file and get the corresponding formula for AOT than to fight
> with 51821 lines of Fortran source code that is numerically unstable. Maybe
> I can help with getting AOT at 550nm from an AERONET file avoiding the
> Fortran version of 6S.
> >
> >
> > Ok but I'm not able to create this kind of routine on my own. If
> someone, more expert than me, can help me in translating the 6S/Py6S
> functions I can go on in this way otherwise for me it's easier to use the
> fortran source code.
>
> Apparently the AERONET data are simple CSV files. You can import them with
> r.in.xyz or v.in.ascii.
>
> Still, I think it is up to the user to decide on the source of AOT values.
> AERONET is one of many possible sources.
>

Ok but I know that Roberta  want try to simplify the procedure for
atmospheric correction. In particular she would like to add an option (not
the only one) to read automatically the AOT at the wave length of 550 nm
from the AERONET file.

The steps to do this IMHO are:

1) read the file (using GRASS or maybe better Python)

2) a formula to calculate the AOT550

Unfortunately I have no idea about the 2nd point :-(

R




>
> Markus M
>
>
> > Here [0] a link to my Github repository in which you can find the small
> script that I wrote using the Py6S library to compute AOT at 550nm
> >
> > Roberta
> >
> > [0]
> https://github.com/RobiFag/GRASS_clouds_and_shadows/blob/master/read_aeronet.py
> >
> >>
> >>
> >> Markus M
> >>
> >> >
> >> > 2018-06-27 14:01 GMT+02:00 Moritz Lennert <
> mlennert a club.worldonline.be>:
> >> >>
> >> >> On 27/06/18 13:54, Roberto Marzocchi wrote:
> >> >>>
> >> >>>
> >> >>> Il giorno mer 27 giu 2018 alle ore 13:47 Markus Metz <
> markus.metz.giswork a gmail.com <mailto:markus.metz.giswork a gmail.com>> ha
> scritto:
> >> >>>
> >> >>>     Hi Roberta,
> >> >>>
> >> >>>     On Wed, Jun 27, 2018 at 1:20 PM, Roberta Fagandini
> >> >>>     <robifagandini a gmail.com <mailto:robifagandini a gmail.com>>
> wrote:
> >> >>>      >
> >> >>>      > Hi all!
> >> >>>      > I need to compile the 6S library in GRASS in order to
> install the
> >> >>>     python library Py6S [0].
> >> >>>
> >> >>>     do you really need Py6S? Can't you use i.atcorr instead?
> >> >>>
> >> >>>
> >> >>> She use Py6S to calculate imput for i.atcorr
> >> >>
> >> >>
> >> >> That seems a bit overkill: why use Py6S to then use i.atcorr ? What
> are you trying to get from Py6S ?
> >> >>
> >> >> Moritz
> >> >>
> >> >
> >
> >
>
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