[GRASS-user] i.atcorr with Sentinel2

Stefan Blumentrath Stefan.Blumentrath at nina.no
Tue Jan 23 06:24:37 PST 2018


OK, sounds doable for me ;-).
Will look at it tonight. Most of the other changes for Sentinel-2B are already in place (I hope).
Not sure if I manage to add python tests as well, looks like current tests are more manual?

Cheers
Stefan
________________________________________
Von: Markus Metz [markus.metz.giswork at gmail.com]
Gesendet: Dienstag, 23. Januar 2018 14:50
An: Stefan Blumentrath
Cc: Markus Neteler; GRASS user list
Betreff: Re: [GRASS-user] i.atcorr with Sentinel2

On Tue, Jan 23, 2018 at 2:19 PM, Stefan Blumentrath <Stefan.Blumentrath at nina.no<mailto:Stefan.Blumentrath at nina.no>> wrote:
>
> OK, will give it a try.
>
The first part is more important because it 1) fixes the interpolation to 2.5 nm steps, and 2) helps iwave.cpp to load the response values.
>
> For the second part I am not sure if I properly understood where min - max wavelength for each band should be printed to.
>
> Do you mean to replace
>
>     # convert limits from nanometers to micrometers
>
>     lowerlimit = wavelengths[0]/1000
>
>     upperlimit = wavelengths[-1]/1000
>
>
>
> Or just as a screen output?

Just a screen output to help update the manual
>
> You did not mean band value limits, right?

No, e.g. in the manual is

Sentinel2A Coastal blue band B1 (430nm - 457nm)

and this range could be printed out to screen based on the actual response. This range can then be copied to the manual, making life a bit easier for the person updating the manual.
>
> Not sure I am of help/useful for fixing create_iwave.py, but I`ll do my best.

Your help is welcome!

Markus M

>
> Cheers
>
> Stefan
>
>
>
>
>
> From: Markus Metz [mailto:markus.metz.giswork at gmail.com<mailto:markus.metz.giswork at gmail.com>]
> Sent: tirsdag 23. januar 2018 13.02
> To: Stefan Blumentrath <Stefan.Blumentrath at nina.no<mailto:Stefan.Blumentrath at nina.no>>
> Cc: Markus Neteler <neteler at osgeo.org<mailto:neteler at osgeo.org>>; GRASS user list <grass-user at lists.osgeo.org<mailto:grass-user at lists.osgeo.org>>
>
>
> Subject: Re: [GRASS-user] i.atcorr with Sentinel2
>
>
>
>
>
> On Tue, Jan 23, 2018 at 12:25 PM, Stefan Blumentrath <Stefan.Blumentrath at nina.no<mailto:Stefan.Blumentrath at nina.no>> wrote:
> >
> > No problem. Any chance I can contribute to maintenance of create_iwave.py?
> >
> > What needs to be done? Take your latest changes into account?
>
> nodata handling should be changed. In read_input(), missing values should be set to zero. Then for each band, leading and trailing zeros would be set to -1. This helps interpolate_band() to get the correct subrange.
>
> For each band, create_iwave.py should print out the band name and the wavelength as min - max. Care must be taken when finding reasonable min and max wavelengths: find the max response, then go back while response > threshold to find the min wavelength. Go forward while response > threshold to find the max wavelength. As threshold I suggest 0.1 to eliminate noise in the response values.
>
> Markus M
>
> >
> >
> >
> > If you think it makes sense I will try to create a patch for adding S2B to i.atcorr (would be a nice exercise and does not seem too complex)? Will open a ticket and start working on it unless you tell me different.
> >
> >
> >
> > Cheers
> >
> > Stefan
> >
> >
> >
> >
> >
> >
> >
> > From: grass-user [mailto:grass-user-bounces at lists.osgeo.org<mailto:grass-user-bounces at lists.osgeo.org>] On Behalf Of Markus Metz
> > Sent: tirsdag 23. januar 2018 12.03
> > To: Markus Neteler <neteler at osgeo.org<mailto:neteler at osgeo.org>>
> > Cc: GRASS user list <grass-user at lists.osgeo.org<mailto:grass-user at lists.osgeo.org>>
> > Subject: Re: [GRASS-user] i.atcorr with Sentinel2
> >
> >
> >
> >
> >
> > On Tue, Jan 23, 2018 at 11:51 AM, Markus Neteler <
> > neteler at osgeo.org<mailto:neteler at osgeo.org>> wrote:
> >
> > >
> > > On Tue, Jan 23, 2018 at 11:09 AM, Žofie Cimburová
> > > <
> > zoficimburova at gmail.com<mailto:zoficimburova at gmail.com>> wrote:
> >
> > > > Forgot to cc the list.
> > > >
> > > > The CSV and the cpp template:
> > > >
> > https://www.dropbox.com/sh/9cnhsl59kvmx4o1/AABwnEVHdxfW_PqrB5Xcpczda?dl=0
> >
> > >
> > > Great! Would you mind to also convert the S2A table? AFAIK it got
> > > updated due to recalibration compared to what we currently have.
> >
> > please wait a bit with creating the cpp template, create_iwave.py needs some maintenance
> >
> > Markus M
> >
> >
> >
> > >
> > > markusN
> > > _______________________________________________
> > > grass-user mailing list
> > > grass-user at lists.osgeo.org<mailto:grass-user at lists.osgeo.org>
> > > https://lists.osgeo.org/mailman/listinfo/grass-user



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