基于北斗短报文的海洋观测实时通信系统的设计与研发

北斗一代和北斗二代短报文每次通信数据长度只有78个字节，每次通信后间隔60秒或者300秒才能进行下一次通信，远远满足不了海洋观测实时通信的需求。设计了一套基于北斗短报文的海洋观测实时通信系统，北斗多卡机作为数据发送端，采用哈夫曼压缩算法将观测数据压缩后分成多个数据包，通过多个北斗卡分别发送，岸站接收系统接收到分包的数据后，将接收的数据包解压缩并整合成完整的观测数据。哈夫曼压缩算法将观测数据压缩50%左右，将1组观测数据压缩后发送3次，通过岸上3个月和海上1个月的测试，观测数据接收成功率达到了96%以上，验证了基于北斗短报文的海洋观测实时通信系统的可行性和实用性。

Design and development of real-time communication system for ocean observation data based on Beidou short messages

First- and second-generation Beidou short messages have a data length of only 78 bytes per communication, and the interval between successive communications is 300 s, which is insufficient for the real-time communication of ocean observations. A real-time communication system for ocean observation data based on Beidou short message is designed. The obtained data is sent through Beidou multicard machine by employing the Huffman compression algorithm to compress the observation data into multiple data packets. These subcontracted data are then transmitted through multiple Beidou cards, which are received by the shore station receiving system. Further, the received data package is decompressed and integrated into complete observation data. The Huffman compression algorithm is used to compress the observation data by about 50%. Moreover, each set of observation data is compressed and sent three times. After testing for three months on shore and one month at sea, the success rate of observation data reception was more than 96%. This verifies the feasibility and practicality of the real-time communication system for ocean observation based on Beidou short messages.