[GRASS-dev] compile 6S library in GRASS

[Markus Metz]

On Wed, Jun 27, 2018 at 3:06 PM, Roberta Fagandini <robifagandini at gmail.com>
wrote:
>
>
>
> 2018-06-27 14:24 GMT+02:00 Markus Metz <markus.metz.giswork at gmail.com>:
>>
>>
>>
>> On Wed, Jun 27, 2018 at 2:16 PM, Roberta Fagandini <
robifagandini at 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.

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 at 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 at gmail.com <mailto:markus.metz.giswork at gmail.com>> ha
scritto:
>> >>>
>> >>>     Hi Roberta,
>> >>>
>> >>>     On Wed, Jun 27, 2018 at 1:20 PM, Roberta Fagandini
>> >>>     <robifagandini at gmail.com <mailto:robifagandini at 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
>> >>
>> >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-dev/attachments/20180627/8d8bd08e/attachment.html>