The diagram of the total process of the BCKA filter. The figure shows, from top to bottom, the filters used corresponding to the four observation methods: the (A) SPST method, (B) SPMT method, (C) MPST method, and (D) MPMT method. The different colored squares indicate different modules of the filter, where a change in the width of the square representing the observed data indicates a reduction in data time due to the deletion of nonsignal data.