Add Unscented Semi-analytical Kalman Filter
Orbit determination based on semi-analytical satellite theory and recursive filter can be done using a specific algorithm: the Unscented Semi-analytical Kalman Filter (USKF). The UKF algorithm needs to re-initialize the orbital state at each observation epoch. However, the time difference between two observations is usually much smaller than the DSST step size (e.g., half a day). USKF reconciles the conflicting goal of both theories. The USKF algorithm has never been presented before, it is its first implementation.
For more details about the equations and the theory, see [1] and the attached file. USKF.pdf
[1]: Taylor S. P., Semi-analytical Satellite Theory and Sequential Estimation, Master of Science Thesis, Department of Mechanical Engineering, MIT, September, 1981