Patent attributes
An apparatus for measuring a position of a moveable platform includes a plurality of transponder modules. The transponder modules include an electromagnetic transmitter adapted to emit an electromagnetic signal, and an acoustic receiver adapted to receive an acoustic signal. At least two of the plurality of transponders are disposed about the position to be measured. The apparatus also includes at least one transceiver module affixed to the moveable platform, which transceiver modules includes an acoustic transmitter adapted to emit an acoustic signal, an electromagnetic receiver adapted to receive an electromagnetic signal. The apparatus also includes a timing mechanism for measuring a plurality of durations between an emission of the acoustic signal and a receipt of the electromagnetic signal, and a computing mechanism for processing the plurality of durations to compute the position.
