Notice: Have you occurred any problems when you processed data by using LiDAR360?

[Xingyu Shi]

Hi 

Did you meet many problems you do not know how to solve when using LiDAR 360? Did you doubt  the accuracy or precision of output from LiDAR360?  Are you familiar with the software operation steps for different modules?

Do not worry, this post aims to collect any problems you met before.  You could post any problems below that could be involved in Pre-Processing, Forest, Terrain or other functions. I will check it regularly and respond you as soon as I can.

Hope to talk with you.

[vasan...@gmail.com]

Hi,

I have some confusing parts in ground point classification. 

1. The attached figure shows ground points classified using Lidar360 v4 for a small uav lidar data set (the drone was flown in winter over snow). the scanned area composed of an open area and a forest, with no buildings. I would expect all the points in the open area to be classified as ground, but I don't get that result (dispersion of the points vertically in open area is less than 10 cm). There are sufficient amount of ground points to delineate ground surface, but there are many unclassified points in the open area as well. Am I doing something wrong here?     

 

The parameters I used here are:

2. In general, What exactly is the edge length? I'm not sure I understand it right.

is it the length of P-V1, P-V2, P-V3? Or the length of the triangle on the projected plane, V1-V2, V2-V3, V3-V1?

3. As mentioned in the manual software uses PTIN algorithm in ground point classification. Does the software uses downward densification first and then the upward densification of TIN or just the upward densification? Is the algorithm used in the software a simpler version of PTIN?

Could you please clarify these things for me?

Thank you very much 

[Linhai Chen]

Hi,

For the first question, after running the automatic ground points classification, you can go to Classify > Classify by Height Above Ground (as figure 1), set the minimum and maximum heights to 0 and 0.15 (or any value you want to set)(as figure 2), and the points meet the conditions will be classified as ground points(as figure 3).

For the second question, the edge length is the triangle length generated by the ground points, like V1-V2, V2-V3, V3-V1.

For the last question, the software uses downward densification first and then the upward densification of TIN.

在 2020年6月20日星期六 UTC+8上午1:26:28，vsd...@gmail.com写道：

[Konstantin Tokar]

Hi!

How to use angle corrections of individual lidar beams in ligeoreference 3.2? 

Is "CalibrationFilePathDir" a calibration XML file from Velodyne?