针对目前海上渔船与流放在海面的浮标远距离通讯传输时存在信息易丢失、通讯费用高以及数据显示终端不够友好等诸多问题，对卫星通讯终端（ IDP ）的数据结构与哈夫曼压缩算法展开研究。采用图像分级式哈夫曼编码压缩方法，利用卫星信号收发服务器提供中转，对卫星回传的40组典型数据进行编码解码试验。结果显示，通讯数据流量最高压缩比达到0．58，平均节省通讯成本40％，客户端人机界面友好，实现卫星定位与浮标各项参数的实时显示，控制命令延迟时间仅为5s。最终将压缩算法部署在卫星通讯终端并实时接收远程数据后，控制命令收发数据包完整、无丢帧，声呐探测图像清晰可辨，数据包压缩效果显著，达到了预期效果。此浮标已经应用至南海部分金枪鱼围网渔船，渔船可以通过船载客户端与浮标实现有效通讯并实时接收金枪鱼鱼情信息，通讯成本在可接受范围内。%Currently, during the long-distance communication between the sea fishing vessels and the buoys on the sea, problems exist such as easy missing of information, high cost, unfriendly communication software interface, and so on. In order to solve these problems, the structure of IDP related communication satellite data and Huffman coding were studied in this paper. The Image classification method of Huffman encoding compression was used to code 40 sets of typical data that were transited from satellite signal server. The results showed that the highest compression rate for communication data reached 0.58 and 40% of cost was saved. As the system integrated satellite positioning, particular data of buoy could be displayed in real time on the customized client of computer, which generated perfect human-computer interface, and the delay time of control command was only 5 seconds. With compression algorithm deploying to satellite communication terminal, the complete remote data was received in real time and sonar image was clear; the overall effect of data compression was remarkable and the desired results were achieved. By far, the buoy has been applied on some of tuna seiners in South China Sea, and fishing boats could communicate effectively with the buoys and receive real-time information on tuna fish via marine client, and the cost is acceptable.
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