[GRASS-user] creating high-resolution DMT

[Martin Landa]

Hi,

recently I was playing with DMT products available in Czech Republic, basically:

* DMR4G regular grid of points (spacing 5m)
* DMR5G irregular point network (average spacing ~3m)

When creating raster-based DMT I tested scenarios bellow:

1) create raster with resolution 5m from DMR4G (no interpolation, just
g.region + r.in.xyz/r.in.lidar)

2) create raster with high resolution (less than 3m) with v.surf.rst
(default parameters defined)

Unfortunately v.surf.rst is quite slow (tile with 5e5 points and
region 2000x2500 cells took on my pc about 3hours). I enjoyed very
much parallelization support in GRASS 7.3. Using 8 cores I am able to
process one tile in 20min. It's great. Probably also some tunning
parameters could help(?)

I was thinking about other scenarios as:

3) import points using r.in.xyz/r.in.lidar on desired resolution and
fill holes with r.fillnuls (but it will be also slow)

4) use v.surf.bspline

What is your experience and how you would process such data?

Thanks for your feedback in advance! Martin

-- 
Martin Landa
http://geo.fsv.cvut.cz/gwiki/Landa
http://gismentors.cz/mentors/landa