The range of an AIS station depends on its position. The most important factor is the altitude of the antenna. An antenna placed 15 meters above sea level will receive AIS information within 15-20 nautical miles. With an antenna placed about several 100 meters above sea level, an even wider range can be achieved. The higher, the better - this has to do with the earth's curvature, which affects the reception of AIS signals if an antenna is placed too low. Other factors influencing the reception range are the antenna type, barriers blocking the antenna, and weather conditions.