[GRASS-user] import satellite data in Grass

Martina Schaefer smartina at mun.ca
Wed Jun 25 09:15:54 EDT 2008

Hi Moritz,

what you propose sounds good for me ... but it didn't work :-(

>> 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 ...
> You could use v.mkgrid to create a vector grid,
I created such a grid. This grid does not appear in the list ¨Select 
item" when I do "add a raster layer" in the GIS Manager. I hope this is 
As Rows and Columns I put the rows an columns of my x-y gridding, I hope 
this is correct?

> add a column for number 
> of crevasses with v.db.addcol,
in v.db.addcol my new grid appears in the list of items for "vector map 
for which to edit attribut table), I put layer=1 and name=D
then I get

"DBMI-DBF driver error:
SQL parser error in statement:
Error in db_execute_immediate()
Error while executing: "ALTER TABLE density ADD COLUMN D
ERROR: Cannot continue (problem adding column)."

Has anybody an idea what this could mean?


More information about the grass-user mailing list