[GRASS-user] r3.in.xyz

[Moritz Lennert]

Le Sun, 1 Jul 2018 13:27:03 -0400,
Francois Chartier <fra.chartier at gmail.com> a écrit :

> Hi,
> 
> I am reposting the initial question: 
> 
> “I am working with a data set that consists of borehole logs with a
> Top of a layer (layer 1) and the top of the underlying layer (layer
> 2) (which is also the bottom of the overlying layer 1).  Everything
> in between the elevation of top of layer 1 and top of layer 2
> correspond to a Layer 1 property.  
> 
> The thickness of Layer 1 varies and this layer may not exist
> everywhere (pinches out).  Above the Layer the property is different;
> in other words the property only starts below the Top of layer 1
> until the underlying Top of the next layer. Not sure of the
> capabilities of the interpolation in Grass and working with a very
> large data set (i cannot link every top of layers together), my first
> approach was to create a each Layer property for every elevation
> slice along each Borehole axis, interpolating soil properties at
> every elevation between Boreholes. 
> 
> The key question is can v.vol.rst (changed this from r3.in.xyz)
> interpolate in 3D without a Property at every elevation slice, 
> • while respecting the condition that above the Top of the layer 2,
> the property corresponds to the Overlying top layer 1, and 
> • that the property is continuous until the next underlying layer 3 -
> can someone confirm this? To provide a bit of background, borehole
> data bases, identify the top of layer as encountered when drilling
> downwards, and provide the elevation of the next layer (pick); in
> between the soil property is the same, however there is no data
> points.  When interpolating, while there is no data point in between
> the two geological picks, the property should still have weight in
> the interpolation process.”
> 

v.vol.rst is a tool to interpolate a continuous value into a 3D space.
So, I do not think that it is the tool you are looking for.

As already mentioned before:

> You probably want to use something like r.to.rast3. This would mean 
> interpolating each layer separately into 2D elevation maps and then 
> assemble them into 3D using r.to.rast3.

Have you tried this approach ?

Moritz