[GRASS-user] import satellite data in Grass

[Martina Schaefer]

Hi Hamish,

thanks for your fast answer.

Hamish wrote:
> Martina:
>> What I want to do now, is to overlay the images with a raster and
>> define (in a first time at least by hand) a value for each of the
>> the raster cells. Is there anything foreseen in Grass that could
>> help me with this? Or do I have just to write a table in any other
>> editor?
> 
> could you please expand a little bit more? I have trouble understanding exactly the process you wish to do..  r.coin? r.patch? r.mapcalc?
> 'd.rast -o' + d.what.rast?
What I want to do is the following:
I have satellite photos from a glacier and we want to get an idea of the 
distribution of the crevasses over this glacier.
In a first step we want to assign every 100x100m grid cell of this 
glacier a value reflecting if there are very little, some, a lot of 
crevasses. As we don't know for the moment how to do this automatically 
(perhaps it would be possible to use the color in a next step), the idea 
was to define this value by "eyeballing". Any ideas how to do this a 
better way are welcome, too, but I think it's not easy.
Now the questions is "only" how to handle the grid and my values in 
Grass ... or perhaps it would be better to print the image + the grid 
and write a table by hand....



Regarding the other questions, I'll first have to have a look to the 
thread from March and the other suggestions.

Thanks,
                   Martina