Changes between Initial Version and Version 1 of Processing/Lidarqcprocedure

Timestamp:

Apr 29, 2009, 3:44:46 PM (16 years ago)

Author:

mark1

Comment:

--

Processing/Lidarqcprocedure

@@ +1 @@
+= Lidar QC Procedure =
+
+This page describes the procedure for the QC of the LIDAR data.
+------
+== QC Procedure ==
+
+As it stands this is the Lidar data QC procedure. This could be improved and added to as time allows.
+
+=== Remove noisy points ===
+
+The first stage of the QC is to check the data and remove erroneous points. This can be done in Microstation/TerraSolid by creating a macro. It should be straightforward to script this into a GIS such as GRASS too.
+
+In Terrascan goto Tools -> Macro
+
+Press Add to add routines to the Macro.
+
+ * Any class to default class (Routine: by class)
+ * Remove groups of low points (Routine: low points)
+ * Remove single low points (Routine: low points)
+ * Remove isolated points (Routine: isolated points)
+
+To run on large projects use "selected files" instead of reading all LAS files into memory.
+Check the result to see what points have been selected. 
+
+To delete the points: Point -> Delete -> by class
+
+Can select/deselect points using the Add Point tool individually selecting points to get points which were missed by the classification algorithms.
+
+To remove haze layers, use elevation to threshold (Routine: by absolute elevation). Select an elevation range whose minimum is well above any ground targets and maximum above the haze layer.