“…The duration clustering based on the DBSCAN algorithm is performed on the connected domains, and the density parameter of sample distribution within the neighborhood is set to (30,1), which represents clustering with at least one point in a circular neighborhood with a radius of 30. The clustering result is shown in Figure 6, where labels [1,2,4,5] are category 1, label 3 is category 2, labels [6,8,10,11,14,15,17,19,20,22,24] are category 3, and labels [7,9,12,13,16,18,21,23] are category 4. Due to the duration of category 1 being equal to the observation time, labels [1,2,4,5] belong to fixed-frequency interference signal.…”