Changes between Version 8 and Version 9 of Sensors/LeicaLIDAR/FWMarksNotes

Timestamp:

Jan 26, 2010, 11:55:36 AM (14 years ago)

Author:

mark1

Comment:

--

Sensors/LeicaLIDAR/FWMarksNotes

@@ -37 +37 @@
   * Displays waveform and discrete points
   * There is a "constant" timing offset between the waveform and discrete points - thought to be due to processing time. This should be removed at calibration
+  * In waveviewer "Ret point loc" is the discrete return time (from emit to receive) for the first return
+  * intensity is the value for each discrete return
 
  * New version of Terrascan capable of displaying full waveform data and "creating extra" points from the waveform
@@ -60 +62 @@
   * Use points throughout flight line not just at start to derive the offset.
   * Procedure
-   * In waveviewer "Ret point loc" is the discrete return time (from emit to receive) for the first return
-   * intensity is the value for each discrete return
+   * Check LAS file is suitable by loading into LASHistoViewer and checking AGC is fairly constant (should be a tight/narrow histogram in the centre)
+   * Select view by time and volt in waveviewer and zoom into the graph
+   * Find a discrete point with ~ 1V intensity value
    * Measure the distance between discrete and full wave peak by zooming into the image and counting the time difference along the x-axis.
+   * Can enter the offset value into waveviewer to check discrete and peak align (enter the value in picoseconds)
+   * Repeat this for a few samples throughout the file and take an average.
+ * Terrascan new options - waveform viewer and point extraction
+  * Need to import trajectory
+  * then flightline -> deduce from time
+  * Should be able to view waveforms now
+  * Waveform display settings
+   * sample height - changes y scale
+   * maximum value - changes x scale
+  * 3D drawing
+   * draws a coloured vector onto the design file depending on the waveform intensity. To remove it, you need to select the line and delete it.
+   * ambient noise - change the threshold level of noise for colour coding the waveform vector