instead reflect the pulse p back to the transducer 72 as particularly shown in fig2 as the pulse p travels it expands parallel to a plane defined by the x and y axes based upon the strength direction and or time of flight of the pulse p at or to a particular transceiver 76 the position of the transceiver 76 relative to the transducer 72 along the x y plane can be determined simultaneously as particularly shown in fig3 the pulse p expands upward and downward relative to a datum plane d which is positioned at a height in the bop even with the transducer 72 and which is substantially perpendicular to the axis a of the running tool 20 based upon the strength direction and or time of flight of the pulse p at a particular transceiver 76 the height h of the transceiver 76 relative to the transducer 72 can be determined as well once the above data about the strength direction and or time of flight of the pulse p is collected by the transceivers 76 the information can be sent to a controller or processor 80 which uses known triangulation techniques to determine the position of each transceiver 76 relative to the transducer 72 the.