Trimble TX8 - Measuring the ground-to-bottom mark distance; Computing the instrument height (IH)

3 Setup
Measuring the ground-to-bottom mark distance
Measure the distance which separates the Known Point on the ground to the Bottom Mark on the
side of the instrument. This measured distance will be called Hm (or Bottom Mark). To obtain the
True Vertical value, please use the formula given hereafter.
Computing the instrument height (IH)
To calculate the Instrument Height (IH), please insert the measured distance (Hm) into the formula
below:
The Hm distance is corrected to obtain a vertical measurement to the Bottom Mark. This vertical
measurement is called (Hc). The distance from the Bottom Mark to the Top Mark is added to the
(Hc) to obtain the Instrument Height from the Known Point to the Trunnion axis (Ih).
Trimble TX8 3D Laser Scanner User Guide 51