Version 2 (modified by emca, 14 years ago) (diff)


Viewing Full Waveform Data in TerraScan

In order to view the full waveform data you first need to create trajectory files. With the RawLaser data loaded in ALSPP select Utilities > Generate trj files. This creates an individual trajectory file for each flightline.

In TerraScan, select Manage Trajectories ( / icon) from the General tool bar. Under File > Set Directory select the location of the trj files.

Alternatively you can use the .sol file. Under Manage Trajectories > File > Import Files > *.sol. This creates a .trj covering the entire project (which is included with the delivery).

Load in a full waveform .LAS files. It is advisable to create a small fence and only load points inside the fence as TerraScan can't seem to cope with entire flightlines.

From the main TerraScan window select Flightline > Deduce Using Time.

On the main TerraScan toolbox select View Waveform Data to open the waveform viewer (the sideways barchart icon, on the bottom right of the Main toolbar). Under Settings > Display Settings you can adjust how the wave is viewed by varying maximum value (x axis) or sample height (y axis).

WaveForm Extractions:

The PI may request waveform extractions to be included with the delivery. These are ASCII files (one file per return) containing the full waveform information.

  • Draw a fence around the area of interest
  • Open the View Waveform Data window
  • File > Save As Text

Extract Echoes:

This tool can be used to create additional discrete points from the full waveform data. Use the ambient noise value to set the threshold for detecting peaks (on the waveform viewer under Settings > Display Settings).

  • Draw a fence around the area of interest
  • Select Extract Echoes from the waveform toolbar