Fig. 3
From: Root tracking using time-varying autoregressive moving average models and sigma-point Kalman filters
NMSE (dB) boxplots (upper panel, a–c), absolute difference between simulated and estimated PSD (middle panel, d–f), and time evolution of NMSE (bottom panel, g–i) for Scenario I (left panel, a, d, g), II (middle panel, b, e, c), and III (right panel, g, h, i). Blue, red, yellow, and green boxplots/curves refer to direct-form models estimated by KF-RPLS and cascade-form models estimated by KF-RPEM, RB-UKF, and RB-CDKF,respectively