  A quantum trajectory describes the evolution of a quantum system undergoing
indirect measurement. In the discrete-time setting, the state of the system is
updated by applying Kraus operators according to the measurement results. From
an experimental perspective, these Kraus operators can depend on unknown
physical parameters p. An interesting and powerful method has been proposed in
[1] to estimate a parameter in a finite set; however, complete results of
convergence were lacking. This article fills this gap by rigorously showing the
consistency of the method, whereas there was only numerical evidence so far.
When the parameter belongs to a continuous set, we propose an algorithm to
approach its value and show simulation results.
