Decimeter-level positioning accuracy is the premise for most ocean applications, such as ocean development and ocean engineering construction. Although the existing real-time precise point positioning method can achieve economical decimeter to centimeter-level positioning accuracy based on Global Beidou Short Message Communication, they can only broadcast limited satellites for regional users. This is because the above method maintains minimum resolution of real-time precise satellite orbit and clock corrections using a single-card GBSMC. We proposed an ocean decimeter-level real-time BDS PPP method based on dual-card GBSMC to implement global positioning service. First, the encoding ranges of real-time precise satellite orbit and clock corrections were redefined to reduce occupied digits based on 2-month data. Second, the resolution adjustment strategy for real-time precise satellite orbit and clock corrections at the service-end was proposed to broadcast 24 global BDS-3 Middle Earth Orbit (MEO) satellites based on dual-card GBSMC device. Last, aiming at the frequency limitation of GBSMC, the real-time correction method at the user-end was employed due to the change of equivalent distance within 1 min at the centimeter-level. The proposed method was verified by six static stations around the world, and the average positioning accuracy was 0.089 m and 0.103 m in the horizontal and vertical directions, respectively. Meanwhile, compared with the original SSR scheme, the proposed method had a longer convergence time. Furthermore, the real-time kinematic ocean multi-users experiment with reference to XP service of Kongsberg DPS 132 receiver was carried out. The results showed that the positioning accuracy was 0.132 m and 0.217 m in the horizontal and vertical directions after converged.

分米级定位精度是海洋开发、海洋工程建设等大多数海洋应用的前提。现有的基于全球北斗短报文通信的实时精密单点定位方法虽然可以实现经济的分分至厘米级定位精度，但只能向区域用户广播有限的卫星。这是因为上述方法使用单卡GBSMC来保持实时精确卫星轨道和时钟校正的最低分辨率。提出一种基于双卡GBSMC的海洋分米级实时BDS PPP方法来实现全球定位服务。首先，根据2个月的数据，重新定义了实时精密卫星轨道和时钟改正的编码范围，减少占用位数。其次，提出了基于双卡GBSMC设备播送全球24颗北斗三号中地轨道（MEO）卫星的服务端实时精密卫星轨道和时钟校正的分辨率调整策略。最后，针对GBSMC的频率限制，由于等效距离在厘米级发生1 min内的变化，采用用户端实时校正方法。该方法经全球6个静态站验证，水平和垂直方向平均定位精度分别为0.089 m和0.103 m。同时，与原始SSR方案相比，该方法具有更长的收敛时间。此外，还参考Kongsberg DPS 132接收机的XP服务进行了实时运动海洋多用户实验。结果表明，收敛后水平和垂直方向的定位精度分别为0.132 m和0.217 m。