Abstract: A method and apparatus for reducing electromagnetic interference (EMI) and jamming in Global Positioning System (GPS) receivers operating on rolling or spinning platforms and/or environments is provided. An antenna system having a pair of diametrically-mounted elements provides interferometric cancellation for spatial and polarization nulling of interference signals. The antenna system, operating in conjunction with multiplexing and anti-jamming electronics, provides interference suppression for a GPS receiver connected thereto. Interference cancellation is provided in jamming and non-jamming environments by selectively employing spatial or polarization nulling of the interference signal.