[Liblas-devel] LAS 1.2 comments

[Howard Butler]

Hello,

The following are comments I would like to make regarding the LAS 1.2  
specification:

- Page 9 states "Scan Angle Rank:  The scan angle rank is a signed one- 
byte number with a valid range from -90
to +90."  All of the rows in the Point Record Format tables for scan  
angle rank say "Scan Angle Rank (-90 to +90) – Left side unsigned char  
1 byte *"  I think the types being specified are inconsistent.  The  
1.1 spec had this issue as well.

- Placing the Global Encoding at the 3rd position in the header breaks  
compatibility with readers that already accept 1.1 and 1.2 data  
because they must account for movement of all of the other header data  
members.  If this was placed at the end of the header, and the Point  
Record Format was 0 or 1, a 1.1 reading software would be able to  
continue to read the 1.2 files without interruption and throw an error  
if they see Point Record Format 2 or 3.

- I think Point Record Formats 2 and 3 should be reversed.  Point  
Record Formats 0 and 1 increase in storage size, but formats 2 and 3  
do not continue this pattern.

http://intranet.asprs.org/standards/LAS1_2_Final.pdf

Sincerely,

Howard Butler
liblas.org