An improved vector matching algorithm for underwater gravity aided navigation

Gravity matching algorithm is the core technology of gravity aided inertial navigation system (INS) for underwater vehicles. Conventional matching algorithms rectify INS deviation by analyzing the INS data and measured value according to a specific correlation analysis function. However, its reliability is easily affected by environmental disturbances, leading to low accuracy and even mismatching. For the purpose of improving the precision of the matching process, an improved phase relationship vector matching algorithm is proposed. With the high short-time accuracy of INS, adding the phase relationship between adjacent sampling points acquired by INS into the correlation analysis function and recalculate the particle weight in the particle filtering process. Simulation tests indicate that compared with the pioneer algorithm, the improved vector matching algorithm performs well with higher precision and robustness.