The Air Force Assimilative Photospheric flux Transport model (ADAPT), is a magnetic flux propagation based on Worden-Harvey (WH) model. ADAPT would be used to provide a global photospheric map of the Earth. A data assimilation method based on the Ensemble Kalman Filter (EnKF), a method of Monte Carlo approximation tied with Kalman filtering, is used in calculating the ADAPT models.
Godinez Vazquez, Humberto C.,Hickmann, Kyle Scott,Arge, Charles Nicholas,et al. The Role of Scale and Model Bias in ADAPT's Photospheric Eatimation. 2015-01-01.