Shore to Ship Steerable Electromagnetic Beam System Based Ship Communication and Navigation

Electromagnetic waves prove to be a common ground for producing integrated systems that use a single transmitter, receiver, and computer system to perform communication, navigation, and surveillance activities. A steerable beam array antenna serves to communicate from shore to a moving ship close to the harbor. In this paper, the communication system parameters are used also to navigate the ship to a predetermined harbor dock. Knowledge of the electromagnetic radiation pattern of the beam steering array antenna, the position of the ship, and the predetermined trajectory for the ship are used to create an on-line navigational system that is driven by the received communication signal power. The discrepancies in signal power measured and the expected received power are used as an indicator that the ship is not properly aligned to the transmitter beam peak point. This discrepancy that is obtained by a signal processor is used to reset the rudder angle through a PID controller. It is shown that this system successfully keeps the ship within the border lines of the trajectory that had been marked out to guide the ship to its harbor dock. Moreover, the antenna electromagnetic beam, like a torch, moves a step ahead of the ship along the trajectory, allowing for automatic navigation of the ship as the ship’s rudder is activated to move the ship to keep within the antenna beam’s half-power points.