  System identification is an integrant part of control theory and plays an
increasing role in quantum engineering. In the quantum set-up, system
identification is usually equated to process tomography, i.e. estimating a
channel by probing it repeatedly with different input states. However for
quantum dynamical systems like quantum Markov processes, it is more natural to
consider the estimation based on continuous measurements of the output, with a
given input which may be stationary. We address this problem using asymptotic
statistics tools, for the specific example of estimating the Rabi frequency of
an atom maser. We compute the Fisher information of different measurement
processes as well as the quantum Fisher information of the atom maser, and
establish the local asymptotic normality of these statistical models. The
statistical notions can be expressed in terms of spectral properties of certain
deformed Markov generators and the connection to large deviations is briefly
discussed.
