宁波—舟山海域船舶接收MSI时的困难分析

海上安全信息（MSI）对船舶航行安全起到非常重要的作用，航行在宁波-舟山海域的船舶，在接收上海海岸电台（XSG）通过HF NBDP（High Frequency Narrow Band Direct Printing）播发的MSI时，经常会遇到通信不良、接收信号很差的情况，尤其在夜晚．就这一现象利用无线电通信的有关知识进行了详细地分析，并在此基础上提出了有效的应对措施来改善接收效果，对航行在此海域的船舶在接收MSI时具有一定的参考价值．

ANALYSIS OF DIFFICULTIES ABOUT SHIP'S RECEIVING MSI IN THE WATERS OF ZHOUSHAN-NINBO

Maritime Safety Information （MSI） acts a very important role on the side of the ship navigation safety. While navigating through the sea-waters of Ningbo-Zhoushan, many difficulties occur when the ships receive the MSI by HF NBDP broadcasting from Shanghai coast station, especially at night, the receiver can not gain any useful signal because of the poor receiving signal. On the basis of a deep analysis of the phenomena by using of the knowledge of radio wave communication theory, the author puts forward some countermeasures of improving the receiving quality in the hope that they are used as references for the ships＇navigation thereby.