Polarimetric radar for accurate navigation

A novel and commercially viable solution to the problem of blind navigation of a ship along a confined waterway is described. The solution is based on the use of radar polarimetry. At the heart of the system is a patented passive (nonpowered) retrodirective reflector that is capable of rotating the incident polarization through 90°. The reflector is efficient and robust, and has a wide azimuthal response. The new navigation system involves a network of such reflectors placed at known surveyed points along the shores of the waterway. Historical notes on the development of the system are included. The paper presents experimental results that provide the first demonstration of proof of concept. Subsequent sea trials conducted with a version of the system built by Offshore Systems Limited have confirmed the operational viability of this new polarimetric radar-aided system for precise navigation. A section is included that summarizes the accuracy and reliability of the system.