2

How can one change a coordinate system for a .lasd (Lidar) dataset?

The file is currently in UTM_Zone_15N and I am trying to convert it to IL_East.

3

Update:

Depending on the ArcGIS version, some LiDAR tools will allow reprojecting through the Environment settings: Output Coordinate System.

For example, the Tile LAS tool:

The output LAS tiles can be reprojected by ... specifying an Output Coordinate System in the environment settings ... .


Original answer:

LiDAR (.las) files and LASdataset files (.lasd) cannot be reprojected within ArcGIS.

A .lasd file is a LAS dataset file developed by ESRI.

The LAS dataset does not import point data contained in the LAS files; it simply stores reference to these LAS files and surface constraints.

According to ArcGIS Help 10.1 one can set a spatial reference to a LAS dataset going to the ArcCatalog, LAS Dataset properties, and then, XY Coordinate System tab.

However, this won't change/reproject the actual .las files. It is only recommended when the .las files do not originally contain the spatial reference and one knows which CRS they belong to.

Strongly recommend reading: LAS dataset considerations - Spatial reference, which includes ESRI's constraints about this topic.

Alternatively, there are other software which will allow reprojection of .las files (example).

  • 1
    Thank you for the clarification! I actually thought that "lasd" was a typo. – Jeffrey Evans Sep 24 '13 at 23:23
2

You can use the las2las function in libLAS to reproject las files.

-1

Here's some help regarding the lastolas suggestion from Tim in MN.

The issue is that the way that the projection information is written in the LAS files is not being properly parsed by ArcGIS and it is appearing in the southern hemisphere. I have validated that the projection information is correct but that ArcGIS reads it incorrectly.

The solution is to redo the header of the las files and update the projection information. I do this using LAS2LAS like so:

Las2las.exe –I -o -remove_all_vlrs -utm 15T

So I did one file and the command line was like so:

las2las.exe -i 4342-01-25_d_c.laz -o 4342-01-25_d_c.las -remove_all_vlrs -utm 15T

The –remove_all_vlrs switch removes all of the existing variable length records in the LAZ file, including the existing projection information that ArcGIS fails on. The –utm 15T adds a vlr that has the projection information in a format that ArcGIS understands.

tim https://www.facebook.com/minnesotalidar

  • I found that is happening on some RAW data nearby as well.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.