An aortic artery measuring probe, device and a method of measuring the diameter of the aortic artery are provided. The apparatus preferably has a warp gauge device and an off-level gauge device suspended over a container support and base by at least one column for the warp gauge device and a pillar for the off-level gauge device. Then, it is determined for the substream whether any transmission antennas, which satisfy a target value related to the foregoing reception quality when they are used for the retransmission, are existent among the transmission antennas that are candidate antennas to be used for there transmission.