The C-RTK 9Ps is a four-star Real-Time GNSS system, using two c-RTK 9Ps modules, one for the aircraft and the other for the base station. It also supports dual GPS for yaw which can replace the magnetic compass. This is useful for flight in complex magnetic field environments such as close to power lines. Compared to C-RTK 9P, C-RTK 9Ps achieves similar performance at a lower price. It is a very cost-effective centimeter-level positioning module compatible with PX4/ ArduPilot open-source flight controllers. It is an ideal choice for UAV mapping, agricultural applications, high-precision takeoff and landing, ship takeoff and landing, and other applications requiring real-time high-precision navigation.