New types of filters called observation-centered extended Kalman filter (OCEKF) and observation-centered unscented Kalman filter (OCUKF) have been developed to solve complex filtering problems. These filters outperform traditional filters like extended Kalman filter (EKF) and unscented Kalman filter (UKF) in certain situations. The OCEKF and OCUKF are especially effective when dealing with small observation errors. The study explores why these new filters work better in specific scenarios.