I'm trying to generate a DTM from lidar data and I'm new in the
this field.
I have different kind of files which describe the same area (different versions):
- *.dtm
- *.xyz
- *.xyz with variable grid width (1 to 4 meter), according to the information sheet I have.
How would you handle each file format to get a DTM? Specially in the case of the XYZ-data with variable grid width, I have no idea about what to do.
Once you have the DTM, how can I be sure about the correct geographic position of the DTM?
I want to use the DTM to analyse the terrain. Which kind of format (of the DTM) would you recommend?
I use ArcGIS (with extensions) and would prefer a solution process on this platform. However, if there is an open source solution it's fine too.
Best Answer
ArcGIS solutions:
Convert the x,y,z data to a feature class then:
Build a TIN using x,y,z data and then convert this to a raster.
Interpolate the x,y,z to raster.
Use Anudem (
topo2raster
) to create a DEM.Convert point to raster and just set a cell size that is suitable for your x,y,z data (usually only for dense data).
I would output a GeoTiff.
x,y,z can be gridded hence you can use gdal and just convert to another format such as GTIff.
x,y,z can just be point data then use 1,2,3 or 4 above or GDAL Grid.
The position should be fine as you have x and y. You just need to know the coordinate system. You can usually tell this by looking at the numbers in the x,y column and knowledge of your local area.
I would be remiss not to point you to this question as well.