[GRASS-user] Processing Atlas Lidar Data - Problem(s)

[Jamie Adams]

Hi Tim,

When dealing with lidar data, I always import using r.in.xyz first.  You can
easily vary the resolution to generate a quick preview and it will give you
a sense of the data source and what information it contains.  If you then
find you need to do more advanced processing, you can move over to the lidar
tools.

Cheers,

Jamie

On Thu, Mar 10, 2011 at 10:23 AM, TimNorwey <timmy_weyrer at live.at> wrote:

> Hi all!
>
> I´m trying to generate a DEM/DSM out of LIDAR data that I have downloaded
> from the website http://atlas.lsu.edu/lidar/ .
>
> The data can be downloaded as .csv-file. Within this file no attribute
> names
> are given. For test purpose I manipulated the .csv, so that "only" 10,000
> points were left and I added a row at the top "x,y,z" as attribute names.
>
> After doing that I imported the .csv into QGIS using the Plugin "Add
> Delimited Text Layer", stored the points as .shp-file and imported them
> into
> GRASS GIS database using v.in.ogr (as 3D points).
>
> Then I tried to follow the workflow described on the website
> http://grass.osgeo.org/wiki/LIDAR#LIDAR_Tools  (I started at "DEM/DSM
> separation the more complex way").
>
> The first step should be the use of v.extract to separate first and last
> pulse laser points. Because of the reason that I have no information about
> first/last pulse laser points, I skipped this step and tried to follow the
> other steps. But I think this was for nothing, because
> v.lidar.edgedetection
> needs the last pulse laser points and v.lidar.growing needs the first pulse
> laser points. So I don´t write more about this...
>
> I really don´t know how to generate a DEM/DSM based on this data and it
> would be nice if anyone of you has an idea. Is there a possibility to do
> generate a DEM/DSM without using the steps that are described within the
> WIKI page above?
>
> What do you think about the import of the .csv into GRASS GIS via QGIS? Is
> there an easier way to import it?
>
> If you need any further information to understand my problem, just let me
> know.
>
> Tim
>
>
>
> --
> View this message in context:
> http://osgeo-org.1803224.n2.nabble.com/Processing-Atlas-Lidar-Data-Problem-s-tp6158817p6158817.html
> Sent from the Grass - Users mailing list archive at Nabble.com.
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