Patent ID: 8830791

Claim:
An apparatus configured to measure 3D coordinates of a transmitter which transmits a discontinuous wave, comprising: first and second substantially flat reflectors positioned a specified distance apart, each of the first and second reflectors having an elongate shape; a first receiver physically coupled at an asymmetrical location with respect to opposite edges of the first reflector to receive a direct wave from the transmitter and diffracted waves thereof, the diffracted waves being diffracted at the opposite edges of the first reflector; a second receiver physically coupled at an asymmetrical location with respect to opposite edges of the second reflector to receive a direct wave from the transmitter and diffracted waves thereof, the diffracted waves being diffracted at the opposite edges of the second reflector; and a processing device configured to process signals received by the first and second receivers, calculate first and second velocity potential responses or time derivatives thereof based on the respective received signals from the first and second receivers, detect inflection points or peak points in the first and second velocity potential responses or time derivatives thereof due to the respective diffracted waves received by the first and second receivers, and measure the 3D coordinates of the transmitter based on the detected inflection points or peak points.