Changes between Version 5 and Version 6 of Processing/LidarNoisyPoints

Timestamp:

Feb 13, 2015, 2:20:36 PM (10 years ago)

Author:

dac

Comment:

Updated las2las text

Processing/LidarNoisyPoints

@@ -1 +1 @@
 = Post Processing LiDAR Point Clouds=
 
-The usual form of delivery of the processed LiDAR data is in the form of a point cloud. This takes one of two forms; [http://arsf-dan.nerc.ac.uk/trac/wiki/FAQ/lidarasciiformat ASCII text files] or binary [http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html LAS] files. The point clouds contain all the LiDAR data as vectors, a list of individual points, rather than as rasterised data. 
+The usual form of delivery of the processed LiDAR data is in the form of a point cloud. This takes one of two forms; [http://arsf-dan.nerc.ac.uk/trac/wiki/FAQ/lidarasciiformat ASCII text files] or binary [http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html LAS] files. The files contain the coordinates of each detected LiDAR return, from these a raster DEM can be created.
 
 == Removing Noise Points ==
@@ -31 +31 @@
 pt_cloud_filter.exe point_cloud.txt 7 > filtered_point_cloud.txt
 }}}
-
 will create a file called filtered_point_cloud.txt from the points in point_cloud.txt excluding those with classification 7.
 
@@ -37 +36 @@
 === Removing noisy points from LAS files ===
 
-To remove them from LAS files it is suggested to download the [http://www.cs.unc.edu/~isenburg/lastools/ LASTools] package, specifically the [http://www.cs.unc.edu/~isenburg/lastools/download/las2las_README.txt las2las] tool.
+To remove them from LAS files it is suggested to download the [https://github.com/LAStools/LAStools LASTools] package, specifically the open source [http://www.cs.unc.edu/~isenburg/lastools/download/las2las_README.txt las2las] tool.
 
-This can be used to remove noise points by typing:
+The following command can be used to create a copy of the LAS file, removing points flagged as noise:
 
 {{{
-las2las -i point_cloud.txt -o filtered_point_cloud.txt -drop_class 7
+las2las -i point_cloud.las -o filtered_point_cloud.las -drop_class 7
 }}}
 
-which will create a new file called filtered_point_cloud.txt from the points in point_cloud.txt excluding those with classification 7.