[Liblas-devel] LAS file Coordinate Systems

Mateusz Loskot mateusz at loskot.net
Tue Jul 21 19:46:37 EDT 2009


Patel, Ronak Avinash \(US SSA\) wrote:
> Mateusz,
>
> So you're saying the Geotiff specification describes how to handle the
> case where files cross UTM boundaries?

Ronak,

I'm sorry, it's apparently late hour and I've missed the point.
I explained how to handle UTM definitions (zones, etc.) in LAS implementation
but you are asking how to handle data that span across a few UTM zones.

Actually, I'm afraid I don't know what's the best practice in the LiDAR
industry. However, AFAIK, LAS is a "dumb" container used for storage and
transport and it gives what it gets.

So, assuming there is one SRS definition per LAS file, all points
are supposed to be defined in that SRS.
IOW, if the SRS is a particular UTM zone but the cloud expands beyond that
zone, then of course you have a problem with how to handle this data.

This issue is more related to how LAS files are generated.
IMHO, it's more a creator's responsibility to generate consistent dataset.

Disclaimer: I'm a programmer, not RS/GIS analyst, so I may have little
knowledge how the industry works with data.

Best regards,
-- 
Mateusz Loskot
http://mateusz.loskot.net



More information about the Liblas-devel mailing list