There are two basic ways to implement integrated navigation:
(1) Loop feedback method, which uses a classical loop control method to suppress system errors and achieve complementary performance between subsystems. During the Second World War, the United Kingdom first studied this type of system in order to solve the navigation accuracy problem of long-term continuous flight of maritime patrol aircraft.
(2) The optimal estimation method, that is, using Kalman filtering or Wiener filtering, estimates the systematic error from the perspective of probability and statistics optimization and eliminates it. Both methods allow the information in each subsystem to penetrate each other and combine organically to complement each other's performance. However, since the error sources and measurement errors of each subsystem are random, the second method is far superior to the first method. Kalman filtering is generally used when designing integrated navigation systems. Since INS and GPS complement each other in performance, the use of these two systems as subsystems in integrated navigation design is recognized worldwide as the best solution.
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