User guide

5 TX5 Controller Software
this reference height by clicking on the Sync Reference Height button. All further altimeter
measurements will then be done on the basis of this reference height.
For comparable height measurements across different projects, sync the altimeter with a real
altitude. For this, pick a reference position of your scanning site where you know the approximate
altitude above sea level. You may get this value from GPS, a topographic map, or from Google
Earth.
As the altimeter determines the altitude based on the measurement of the atmospheric pressure,
changes in the air pressure caused by changing weather conditions have an effect on the resulting
altitude. To have precise altitude measurements, you should therefore check the reference altitude
from time to time, at least at the beginning of each project day or if you experience changes in the
weather. To do this, move the scanner to your reference position again and compare the altitude
reading with the reference height. If there is a difference, sync the altimeter with the reference
height again.
Trimble TX5 3D Laser Scanner User Guide 93