Having Issues with las2las

[Brett]

Good afternoon! 

I am using las2las to reproject the LiDAR dataset both vertically and horizontally but however I ran into an issue with reprojecting it vertically. I used the -target_epsg flag and was able to reproject it horizontally. The source lidar dataset is in NAVD88 Meters as the vertical. I want to change the units to ft from meters so I used the -target_elevation_feet for the vertical but the output units are in ftus instead of ft. Is this a bug or should I use a different flag to reproject the vertical coordinate system?

Thanks!

[Jochen Rapidlasso]

Hi,

please provide a small sample of data and tell which command you did use in detail and we will have a look at this problem.

Cheers,

Jochen @rapidlasso

[Brett]

Sounds good! However, I won't be able to share our project data but can share with you the iasinfo information of the source data. See below,

 COMPD_CS["NAD83(2011) / UTM zone 12N + NAVD88 height - Geoid18 (metres)",PROJCS["NAD83(2011) / UTM zone 12N",GEOGCS["NAD83(2011)",DATUM["NAD83 (National_Spatial_Reference_System_2011)",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","1116"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["Degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","6318"]],PROJECTION["Transverse_Mercator"],PARAMETER["Latitude_Of_Origin",0],PARAMETER["Central_Meridian",-111],PARAMETER["scale_factor",0.9996],PARAMETER["False_Easting",500000],PARAMETER["False_Northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["X",EAST],AXIS["Y",NORTH],AUTHORITY["EPSG","6341"]],VERT_CS["NAVD88 height - Geoid18 (metres)",VERT_DATUM["North American Vertical Datum 1988",2005,AUTHORITY["EPSG","5103"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Up",UP],AUTHORITY["EPSG","5703"]]] 

Below is the command line that I was using for las2las.

las2las -cpu64 -v -i .*.las  -target_epsg 6405 -target_elevation_feet  -odir "A:\LiDAR" -olaz

[Jochen Rapidlasso]

Hi Brett,

it's sad that you are not able to share data. Even if data are confidential you easy can do something like
    las2las64 -i lake.laz -stop_at_point 10 -translate_raw_xy_at_random 100000 100000 -o non_confidential.laz

to get just a few points out of a dataset to test transformations without any relevant content left.

Nevertheless, we try to help you with the information you gave.
First we saved the WKT to a file "wkt.txt".
Then we add this WKT to our sample file:
    las2las64 -i lake.laz -load_ogc_wkt wkt.txt -o lake_wkt.laz -set_version 1.5 -set_point_type 6
    las2las64 -i lake.laz -load_ogc_wkt wkt.txt -o lake_wkt.laz -set_version 1.4 -set_point_type 6
First approach worked, but till we are probably the first supporting LAS 1.5 we can not test the result using other software.
So we did the second one. Ensure your target LAS format is using WKT.

Then we did run the program like you did (using the 64 bit version native):

    las2las64 -i lake_wkt.laz -target_epsg 6405 -target_elevation_feet -o tmp_ft.laz
and just to check
    las2las64 -i lake_wkt.laz -target_epsg 6405 -target_elevation_survey_feet -o tmp_sf.laz

A check using QGIS shows the correct result.
Using lasinfo64 also shows the correct translated coordinates:

lasinfo64 -i lake_wkt.laz -nc
  min x y z:                  476941.35 4366469.50 2725.29
  max x y z:                  477208.56 4366726.49 2768.74
 
lasinfo64 -i tmp_ft.laz -nc
  min x y z:                  883166.73 3075181.55 8941.24
  max x y z:                  884051.89 3076033.58 9083.79

lasinfo64 -i tmp_sf.laz -nc
  min x y z:                  883166.73 3075181.55 8941.22
  max x y z:                  884051.89 3076033.58 9083.77

So we would say: Everything works very well.

Cheers,

Jochen @rapidlasso