Method and apparatus for reducing electromagnetic interference and jamming in GPS equipment operating in rolling environments

An apparatus for reducing interference in a receiver operating on a rolling platform comprising:

• a pair of diametrically-mounted antennas mounted on the rolling platform;
• means for determining interference levels of radio signals received by the antennas;
• means for determining roll rates of the rolling platform;
• a modulator for generating a spatial null pattern and a polarization null pattern;
• and
• means for selecting between the spatial null pattern and the polarization null pattern based upon the roll rates.

A method for reducing interference in a receiver operating on a moving platform comprising:

• detecting interference or jamming in a radio signal received by the receiver;
• creating a spatial null pattern if platform roll exceeds slow roll;
• calibrating and maintaining the spatial null pattern with a downhill gradient process if interference levels exceed predetermined thresholds and platform roll exceeds slow roll;
• creating a polarization null pattern if the platform has no roll or slow roll;
• and
• calibrating and maintaining the polarization null pattern with a downhill gradient process if interference is present and the platform has no roll or slow roll.