Reprojecting LAS files from local to world projection
Michel Wolters
I have a lot of LAS files (tiled, but not merged) which are in the
RDNEW (EPSG: 28992) projection (the national projection of the
Netherlands) but do not have an embedded projection. For compatibility
purposes with other programs, I need to reproject them to the
projection UTM zone 31N WGS84 datum. I have attempted to do this using
two programs, FME 2012 SP1 and GlobalMapper.
When this is completed, I want to use lastile to merge and retile the
reprojected tiles. Lastile does this without any problems.
lastile -i *.las -merged -o tile -tile_size 125 -buffer 30 -full_bb -
olaz -verbose
Then when I want to use LasGround to identify Ground points
lasground -i *.laz -odir 03-BareEarthClassification_normal -olaz -
verbose
I get the following warning (in similar fashion) for each tile:
Invalid Bounding Box [685450 5.77572E+006 21.231 / 682280 5.7759E+006
29.68]. It does work as normal, but I am wondering if I did something
wrong when tiling and reprojecting.
Does anyone have suggestions on how I can reproject LAS files from a
very localized projection to a world projection? I would use the
las2las but I am not sure if las2las also incorporates projections
such as mine. They have to be embedded in the header first anyway,
something which also can be done with FME 2012 SP1.
Thank you all for your help and Martin for his great work.
- Michel Wolters
Martin Isenburg
seems like the bounding box is messed up (min_x > max_x and min_y >
max_y). did lastile do this? if yes, can you provide me (private
email) an (original) example file (before tiling) in LAZ format?
> [685450 5.77572E+006 21.231 / 682280 5.7759E+006 29.68].
if you stay on the same ellipsoid and you have a TM or LCC projection
you could simply specify the source in the command line, such as
las2las -i in.las -out.las -lcc 609601.22 0 meter 33.75 -79 34.33333
36.16666 -target_utm 31N
but EPSG: 28992 is Oblique_Stereographic. if anyone is willing to
contribute the code for the Oblique_Stereographic to longlat and
longlat to Oblique_Stereographic transform then i could add this and
provide a '-os 155000 463000 meter 52.15616 5.38763889 0.9999079'
switch for you. otherwise i think las2las from libLAS may be able to
do that reprojection for you ...
cheers,
martin @lastools
> --
> Download LAStools at
> http://lastools.org/
> Visit the LAStools group at
> http://groups.google.com/group/lastools/
> Be social with LAStools at
> http://www.facebook.com/LAStools
> http://www.twitter.com/LAStools