Gnss Dual-mode Receiver Solver Algorithm,

GNSS is becoming more and more important in military and political use all over the world. As a self-designed GNSS, XXXX-GPS two modes receiver is of significant importance in China. In this article, a whole solution arithmetic data-flow of the XXXX-GPS receiver is proposed and achieved, from the receiving of the navigation signal to the final solution of the PVT (position, velocity and time) of the receiver.In the solution process, the arithmetic of direct solution, least square, least square with altitude assistance and extended Kalman filter are executed. Based on the error analysis, the method of 'Extended Kalman Filter with LS assistance' is finally used and simulated.At the same time, the popular RAIM (Receiver Autonomous Integrity Monitoring) is studied.