“…Many studies have been done previously to improve the circuit-based model where some of the parameters have been considered, such as the integration of soil ionization effect, current rate of rise, mutual coupling, frequency influence, and others for all types of grounding electrode [13][14][15][16][17][18][19][20][21][22][23]. However, the study regarding the influence of frequency dependent of soil parameters is still not covered entirely since there is only one study for each horizontal and vertical grounding electrode, and under lightning current only for the input signal, and the results is not sufficient since it used the equivalent frequency [16][17][18][19]. Due to the lack of information regarding the issue, further improvement needs to be done to tackle the inaccuracy problem for circuit-based model.…”