# A Novel FECAM-iTransformer Algorithm for Assisting INS/GNSS Navigation System during GNSS Outages
## 2 Theory of INS/GNSS Integrated Navigation System
## Abbreviations

The following abbreviations are used in this manuscript:

INS Inertial navigation system GNSS Global navigation satellite system IMUs Inertial measurement units EKF Extended Kalman filter iTransformers Inverted Transformers FECAM Frequency-Enhanced Channel Attention Mechanism FC Fully Connected LSTM Long Short-Term Memory GRU Gated Recurrent Unit SE-Block Squeeze and Excitation Block RMSE Root mean square error MAX Error Maximum error

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