[GRASS-user] Fwd: Airborne LiDAR data strip adjustment

Adrian Kirilov kirilov.adrian at gmail.com
Sun May 19 05:57:17 PDT 2013


I applied the same method actually (after a bit thinking and reevaluation
of my first idea). I prefer to use v.in.ascii -t -r -z input= fs= z= out= ,
because I'm interpolating the points with v.surf.bspline (bilinear, to be
more precise) afterwards.

I have some more questions now. Sorry, but I don't know if I should put
them in a different e-mail and subject...

I used r.horizon module to build horizon view for 16 directions,
consequently I received as a result 8 output raster maps:
r.horizon elevin=demb30_5_combined at FlemishArdennes direction=0
horizonstep=45 maxdistance=10 horizon=SVF_demb30_5

After that I combined them witn r.mapcalc but with simple addition only:

r.mapcalc:
'SVF_demb30_5_0 at FlemishArdennes + SVF_demb30_5_1 at FlemishArdennes +
SVF_demb30_5_2 at FlemishArdennes + SVF_demb30_5_4 at FlemishArdennes +
SVF_demb30_5_5 at FlemishArdennes + SVF_demb30_5_6 at FlemishArdennes +
SVF_demb30_5_7 at FlemishArdennes'

Is this approach correct?

And how can I change the range value of the output raster after I have set
up first color table with r.colors color=grey. I want to change the range
from 0.0-1.0 to something else, like 0.7-1.0 for example to get more
contrast or brightness. The last is in fact the question from my first
e-mail (see up) with this subject.

Thanks a lot for the help!


Greetings,

Adrian Kirilov


On Sat, May 18, 2013 at 5:37 AM, Hamish <hamish_b at yahoo.com> wrote:

> Adrian wrote:
> > It's a series of points. But how can I export them from all
> > imported files (strips) later into a single one ASCII file into
> > specific region? I think that v.out.ascii for example is only
> > for exporting single file. And I need to export multiple,
> > falling into the region. Is this possible in GRASS?
>
> first set the region and grid size with g.region, check it is
> ok with the -p flag.
>
> then depending on what you want to do:
>
> cat *.asc | r.in.xyz x= y= z= fs= input=- output=mapname method=
>
>   or
>
> cat *.asc | v.in.ascii -r -bt x= y= z= fs= output=mapname
>
>
> r.in.xyz discards points outside of the current region, as does
> v.in.ascii if you use the -r flag.
>
>
>
> if your data is already processed, sorted, and cleaned I'd
> go straight for r.in.xyz myself, but that's just me.
>
>
> Hamish
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20130519/d04e9aa0/attachment.html>


More information about the grass-user mailing list