A fast RTK positioning technique based on INS-assisted cycle-skip processing for indoor Pseudolites positioning systems

For the problem that the GNSS (Global Navigation Satellite Systems) pseudolite positioning receiver often skips cycles and cannot work stably and reliably in the indoor dense multipath environment, a fast indoor RTK (Real-Time Kinematic) positioning technique is studied which using the INS-assisted carrier phase DD(Double-Difference) positioning technology. Its key is the fast algorithm of floating-point filtering of DD integer ambiguity. By updating and iterating with INS (Inertial Navigation System), this algorithm can achieve fast convergence and determination of DD integer ambiguity in the way of OTF (On The Fly), effectively overcome the difficulties caused by cycle-skip, and achieve the goal of fast recovery and reliable operation of indoor pseudolite positioning systems. The research result shows that the RTK positioning algorithm using INS-assisted cycle-skip processing can quickly and reliably solve the floating-point of DD integer ambiguity, which is faster and more effective than the regular cycle-skip repair method. Thereby, the continuous and stable operation of the pseudolite positioning system is effectively ensured.