[GRASS-user] GRASS crashes while running i.atcorr

[Nikos Alexandris]

* Nikos Alexandris <nik at nikosalexandris.net> [2015-05-02 11:38:23 +0300]:

> * Nikos Alexandris <nik at nikosalexandris.net> [2015-05-02 10:21:06 +0300]:
> 
> > 
> > 
> > 
> > * Jake Chila <jake.chila at gmail.com> [2015-05-01 11:33:01 -0300]:
> > 
> > > hi all,
> > > 
> > > So I am trying to run i.atcorr but every time I run it, the whole program
> > > goes unresponsive and crashes. Has anyone experienced this before? Is there
> > > any way I can fix it?
> > > 
> > > One thing that might be causing it is my parameters text file. I'm not
> > > totally sure I understand what all the fields are but here is an example of
> > > the parameter files I have created. This one is for the second band of a
> > > landsat 5 TM scene over central British Columbia
> > > 
> > > 7
> > > 8 15 18.49 -116.027755 50.267045
> > > 2
> > > 0
> > > 0
> > > 0
> > > -1000
> > > 26
> >  
> > Hi Jake.
> > 
> > Please have a close look in the manual. As well, here:
> > <http://grasswiki.osgeo.org/wiki/Atmospheric_correction#Atmospheric_correction>.
> > 
> > If Landsat is your sensor to work with, here is a script around
> > i.atcorr: <https://github.com/NikosAlexandris/i.landsat.atcorr>.  I
> > haven't used this in Windows though, and to upload it into grass-addons
> > I need to test it more.
> 
> Unfortunately, something is broken currently and I have no time to check
> it :-(.

Jake, if you read Python, you could, however, make use of the Parameters python class
defined in
<https://github.com/NikosAlexandris/i.landsat.atcorr/blob/master/parameters.py>.
I will create a text file with the requested parameters suitable for i.atcorr.


An example inside python:

# import class
from parameters import Parameters

# check it out with help()
# help(Parameters)

# create object with desired six s parameters for i.atcorr
ssp = Parameters(geo=8,
 mon=11, day=8, gmt='23:42',
 lon=22.2, lat=33.3,
 atm=2, aer=1, vis=10, aod=None,
 xps=-200, xpp=-1000,
 bnd=26)

# what is it like?
print ssp

Parameters for the 6S atmospheric correction model:
8                               # Geometrical conditions
11 8 23.70 22.200000 33.300000  # Month Day GMT Center Longitude Latitude [DD]
2                               # Atmospheric model [index]
1                               # Aerosols model [index]
10.0                            # Visibility [km]
-200.0                          # Mean Target Altitude [negative km]
-1000                           # Sensor Altitude rel. to xps [negative km] or SatelliteBorn [-1000]
26                              # Satellite Band Number [index]

# export it to an ascii file
p6s.export_ascii("ssp_example.txt")


# what is inside the exported file?
cat p6s_example.txt

8                               # Geometrical conditions
11 8 23.70 22.200000 33.300000  # Month Day GMT Center Longitude Latitude [DD]
2                               # Atmospheric model [index]
1                               # Aerosols model [index]
10.0                            # Visibility [km]
-200.0                          # Mean Target Altitude [negative km]
-1000                           # Sensor Altitude rel. to xps [negative km] or SatelliteBorn [-1000]
26                              # Satellite Band Number [index]

Nikos