A. Didger 4 has to calculate the full range of values for a LAS file. If there is no data in the range specified in the LAS Export dialog, Didger will populate these areas with data. Didger currently has no mechanism to handle NULL or out or range data during export. This issue is fixed in Didger 5.
As a workaround, you can either:
1. Open the LAS file in Notepad or a text editor and replace those values with the NULL value (or any other data you wish).
2. Change the Start Depth and Ending Depth values in the LAS Export dialog to be sure they don't extend past your data.
Updated April 2, 2018