Cycle slips: Detection and correction using inertial aiding
GPS carrier-phase measurements can be used to achieve very precise positioning solutions. Carrier-phase measurements are much more precise than pseudorange measurements, but they are ambiguous by an integer number of cycles. When these ambiguities are resolved, subcentimeter levels of positioning can be achieved. The ambiguity resolution is even more challenging in real-time navigation due to receiver dynamics and the time sensitive nature of the required kinematic solution. The two major approaches of GPS/INS integration are loosely coupled and tightly coupled. The former strategy is simpler and easier to implement because the inertial and GPS navigation solutions are generated independently before being weighted by the Kalman filter. The latter strategy performs the INS/GPS integration in a single centralized Kalman filter. Once a cycle slip is detected, it can be handled in two ways. One way is to repair the slip.
Karaim, M.O. (Malek O.), Karamat, T.B. (Tashfeen B.), Noureldin, A. (Aboelmagd), Tamazin, M. (Mohamed), & Atia, M. (2014). Cycle slips: Detection and correction using inertial aiding.