Modeling of interferences on other satellites in maritime satellite communications

In maritime mobile satellite communications, mechanically controlled tracking systems are used to compensate changes of antenna orientation due to changes of a ship attitude caused by waves or winds of the sea. Orientations of antennas on a ship are limited so that transmitted electromagnetic waves are not affected by structures on the ship. Thus it is allowed to transmit waves when a clearance angle is greater than certain criteria. Our group has researched about fundamental relation between clearance angles and interferences for other satellites or other systems on the ship by numerical simulations for a simplified model. In this report, a realistic ship model is assumed for the simulations. As a result, a clearance angle, which interferences to the receiving satellite are small, has been found out under the conditions of the simulations. A simple model which describes interferences to received levels of the aiming and neighboring satellites is presented.