A geodesic positioning system determines the position of a target point. The system includes a range pole that can be oriented toward the target point. A tilt sensor is arranged on the range pole, detachably where applicable, for generating a tilt angle signal related to the tilt angle of the range pole....http://www.google.ca/patents/US7646339?utm_source=gb-gplus-sharePatent US7646339 - Geodesic position determining system
