In order to analyze the sequence of magnetic pulses during the initial stage of rocket-triggered lightning

we used the measurement data for five classical triggering lightning flashes during the Shandong Artificial Triggered Lightning Experiment（SHATLE） in August of 2014 to statistically analyze these pulses.We applied a transmission-line model to calculate the magnetic field by fitting the measured initial current pulse with Heidler function.The results show that these magnetic pulses can be classified into two categories with distinct differences in magnitude and timescale

namely impulsive pulses and ripple pulses

but the inter-pulse interval is similar

which indicates that the mechanism of generation is probably the identical for both types.The current pulses associated with the ripple pulses are usually difficult to discern in the conventional current measurement at the channel base

so we simulate the single impulsive pulse only and the simulation result is in good agreement with the measurement

which indicates that the sequence of magnetic pulses is radiated by leader current pulses propagating along the triggering wire.The relationship between individual components（i.e.

induction field and radiation field） and the total magnetic field shows that

in the case of rocket height at 152 m above ground

when the observation distance is less than 40 m

the induction field contributes more than 80% to the peak magnetic field.When the distance is greater than 500 m

the radiation field contributes over 80% to the peak magnetic field.