“…The CKF is used to compensate for fast RSOP, which poorly compensates under slow RSOPs. When a sudden change in RSOP occurs, the parameter tracking curve of the EKF will also produce a corresponding sudden change [6] , where a threshold can be set. For this reason, we use a mathematical model of lightning strikes to verify the abrupt parameter changes and to establish a threshold value for the EKF/CKF switching scheme.…”