So what is this person doing? Looking for gold? Not quite.
The crew installing the fibre optic line uses equipment which can drill sideways up to 400 meter underground, avoiding sensitive spots, creeks and streams. The drill is also directional, which means the operator can direct it to go up or down, left or right. For that to work, however, he has to know where the drill head is located so the drill direction can be adjusted if needed. And that is what this gadget does. It receives signals from the drill head so the crew knows whether drilling is going in the right direction or adjustments are needed.