On the Lightning Electromagnetic Fields due to Channel with Variable Return Stroke Velocity

Table 1

and for six engineering current models based on (3).

Model
BG (Bruce-Golde model) [18]	1
TCS (traveling current source model) [19]	1
TL (transmission line model) [9]	1
MTLL (modified transmission line linear model with linear decay with height) [9]
MTLE (modified transmission line model with exponential decay with height) [9]
MTLD (modified transmission line model with current distortion) [20, 21]