[GRASS-dev] New GRASS addon i.sentinel.mask is now available (GSoC 2018 project)

[Roberta Fagandini]

Hi Stefan!
Certainly applying the topographic correction could be very useful to avoid
misclassification.
I did several tests with i.topo.corr but I always got strange results
especially in areas with steeper terrain.
I also tested the topographic correction tool implemented in arcsi [0]
but again the results were not satisfactory at all. This is why I have not
further investigated this issue within my PhD research.

In order to remove misclassifications, e.g. due to topographic shadows, I
implemented the shadow mask cleaning procedure. It intersects the rough
shadow mask with the cloud mask that is shifted according to the sun
position. In this way, all the areas identified as shadows without a
corresponding cloud are removed from the final shadow mask.

I'm still very interested in investigating the topographic correction so if
you have any suggestion please, let me know!!

Ciao,
Roberta

[0] https://www.arcsi.remotesensing.info/index.html

2018-06-14 10:55 GMT+02:00 Stefan Blumentrath <Stefan.Blumentrath at nina.no>:

> Hi Roberta,
>
>
>
> What about topographic correction (i.topo.corr [1])?
>
> Should that be run before as well?
>
> I would assume it has some impact on shadow detection in steeper terrain…
>
>
>
> Cheers
>
> Stefan
>
>
>
> 1: https://grass.osgeo.org/grass74/manuals/i.topo.corr.html
>
>
>
> *From:* grass-dev <grass-dev-bounces at lists.osgeo.org> *On Behalf Of *Roberta
> Fagandini
> *Sent:* torsdag 14. juni 2018 10:29
> *To:* Moritz Lennert <mlennert at club.worldonline.be>
> *Cc:* GRASS developers list <grass-dev at lists.osgeo.org>
> *Subject:* Re: [GRASS-dev] New GRASS addon i.sentinel.mask is now
> available (GSoC 2018 project)
>
>
>
> Hi Moritz!
>
>
>
> 2018-06-14 10:03 GMT+02:00 Moritz Lennert <mlennert at club.worldonline.be>:
>
> On 13/06/18 17:35, Roberta Fagandini wrote:
>
> Hi all!
> The first version of i.sentinel.mask is now available and can be installed
> from the official svn repository.
> i.sentinel.mask is a module for cloud and shadow masks computation and it
> is the first step of my GSoC project.
>
>
> Thank you, Roberta. Great job !
>
>
>
> Thank you!
>
>
>
>
> One question: ISTR that you mentioned that the input to this module has to
> be atmospherically corrected images, i.e. land surface reflectance. Is this
> true ? If yes, then this needs to be mentioned in the man page.
>
>
>
> Yes, it's true! I'm going to add it.
>
>
>
> Roberta
>
>
>
>
>
> Moritz
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-dev/attachments/20180614/aa6855a4/attachment.html>