关键词: 远海, 北斗短报文, 伪距差分定位, 低成本

Abstract: Due to limitations of communication distance, pseudorange differential positioning technique can only be used in most of land areas or inshore ocean areas and cannot be used in remote ocean regions as the traditional communication wireless network, such as Wi-Fi or GPRS are not available, while satellite communication is the only communication means and it is too expensive to be afforded by ordinary users. Short message service of BeiDou satellite navigation system is one feature and it becomes another choice for data transmission due to its cheap price. In this research, pseudorange differential positioning technique based on BeiDou short message service is investigated and a method combining space-relative and time-relative positioning techniques is proposed. The simplifying and encoding measures of transmission data related to pseudo-range corrections are also discussed. Finally, based on practical ocean GNSS observations, performance of pseudorange differential positioning technique is tested with a distance about 1700 km from the rover to the reference station. The numerical test results show that the positioning errors are basically within 1 meter in horizontal directions and 2 meters in vertical direction. As the annual communication fee is only about 800 Chinese Yuan, the proposed method in this research can meet ocean need of many applications.

Key words: remote ocean, BeiDou short message service, pseudorange differential positioning technique, low-cost