Las format definition

This is the .las format to be introduced in SURE 2.0.

The .las and .laz output of SURE is based on the POINT DATA RECORD FORMAT 2,  as specified in the LAS SPECIFICATION Version 1.2 , 09/02/2008

SURE is able to read data up to LAS Version 1.3 and will write pointcloud data in LAS Version 1.2

Xlong32 bitX coordinate
Ylong32 bitY coordinate
Zlong32 bitZ coordinate
Point Source IDunsigned short16 bitBase image from matching (0 based index in imagelist)
Redunsigned short16 bitRed color channel
Greenunsigned short16 bitGreen color channel
Blueunsigned short16 bitBlue color channel
Intensityunsigned short 16 bit 
  • Raw Dense Clouds (3D_Points) and Filtered Clouds (Cloud_Filtered):

Point precision value that relates to the point depth standard deviation (σ) and the project GSD. The values are computed according to the following formula:

I = (σ / GSD) * 10000 

  • True Ortho point cloud (DSM/Cloud_Refined):

4th color channel (typically Near Infrared)

Number of returns
3 bit

For the dense matching the number of returns is equivalent to the number of stereo models. Maximum value of 7 means seven or more.

SURE makes the assumption that after a given number of stereo models (5 to 7), the sample's accuracy does not increase, for that reason we clamp the number of returns to 7

Classificationunsigned char8 bit0 unclassified - 12 overlap points
UserDataunsigned char8 bitAccuracy ( to be determined)