Stellar coronagraphs use closed-loop focal-plane wavefront sensing and control algorithms to create high-contrast dark zones suitable for imaging exoplanets and exozodiacal dust clouds around nearby stars. Model-based algorithms are susceptible to model mismatch, wherein a departure of the coronagraph's true optical characteristics from the assumed model causes reduced control loop performance. Here, we report on a collection of techniques, including prediction-error minimization, expectation-maximization, and maximum-likelihood estimation, for empirically tuning the wavefront control Jacobian matrix in a statistically rigorous fashion during closed-loop wavefront control operations. This mitigates model mismatch and recovers near-optimal control loop performance.
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