In a state estimation scheme with a simple IMU/GNSS setup using EKF, I have always thought the prediction step would be done using a motion model and all sensor measurements would be incorporated via observation updates.
However i have noticed IMU measurements being used for prediction in several works using something called a strapdown inertial navigation (Example) which is used as the prediction model with no mention to a kinematic motion model. Also in this paper i see that the prediction step is done by integrating the IMU measurements with the motion model.
This is slightly confusing with my concept of temporal and measurement update duality. Is strapdown inertial navigation and using a kinematic model are substitutes for each other or are they complementary? Do you know of any works that compare them in case they are analogous? Any good reads to understand these concepts would be appreciated.