[Liblas-devel] Retrieving User Data/Point source ID with LibLAS (python)

[Howard Butler]

On Apr 7, 2010, at 10:17 AM, Aaron Reyna wrote:

> Thanks Howard,
> 
> So, does that mean that libLAS is incapable of extracting that information based on it's current version? Maybe I didn't understand your reply. 

Currently released version, 1.2.1, does not have the capability to provide *both* the point source id and the user_data, only the user_data.  The latest version in the repository does have this capability, however.


> 
> I ran it the other night and looked at the results, it seems to be correct. Striations could be seen in the raster I created that looked similar to that in the intensity raster.  

Excellent, glad you are having success.

> 
> Oh, and it should be noted that only Raw .las files contain this information in the User Data/Point Source Id.

User data and point source id are not the same thing, and my grouping them together as equivalent was incorrect.  user data is a single byte per point, and point source id is two bytes of data per point.


> When those files are imported into usable delineations and grounded, (as in, not per flight line) the Point Id is written over with gps time.
>