“…Here we use the procedure by Garcia-Hiernaux et al (2009). Then, the exact ML is computed using the standard Kalman filter equations for a state space model with stochastic inputs (see, Casals et al, 2016), by iterating on the set of parameters {a 0,1 , a 1,1 , a 0,2 , a 1,2 , a 0,3 , a 1,3 , b 1 , b 2 , b 3 , ψ} and keeping the 0s and 1s in the state space matrices representation constrained to its value. 6 Obviously, the estimation through iterative methods may entail some drawbacks with respect to LS techniques, as computational cost and stability issues.…”