A novel non-contact technique to measure position of a selected point of interest on an object has been developed. The method is based on an ultrasonic ranging system and it is of simple construction and relatively inexpensive. The basic systems consists of one ultrasonic transmitter and various receivers. The transmitter is mounted on the point of interest and the receivers are fixed to an inertial frame of reference. At any given time, the position of the transmitter can be determined indirectly by acoustically measuring the distances between the transmitter and each receiver. The system developed emphasizes on accuracy over a relatively large operating volume, and is robust against reflections. Some potential used include mapping and position feedback for AGV applications, robot end-effector position feedback for real-time control for calibration, and tracking of a selected point of interest of a flexible structure. An analysis of the system, including procedures for installation and calibration is described in detail.