The training apparatus 1 wherein {HEAD ~ each} of {TAIL ~ said at least one transceiver} is an ultrasonic transceiver and each of said at least one reflector is an ultrasonic reflector 
of
The training apparatus 1 wherein { HEAD ~ each } of { TAIL ~ said at least one transceiver } is an ultrasonic transceiver and each of said at least one reflector is an ultrasonic reflector
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH