Analysis of excitation signal effect on grounded electrical-source airborne transient electromagnetic response

We calculated the grounded electrical-source airborne transient electromagnetic response of step wave in the layered earth.using digital filter and Simpson integration method. Based on these obtained values from step wave response, the electromagnetic response of arbitrary excitation wave can be extracted by convolution. We analyzed the response by excitation energy. The higher the excitation energy is, the larger the response is. During the forward calculation, with different conductivities, no significant changes of the responses of half sine wave and triangular wave have been observed in the on-time zone. At the same time, high resistance target quickly enters the noisy area in the off-time zone. It is impossible to retrieve enough information. To solve this problem, the transmitter current adapts the trapezoidal wave or square wave. We have managed to record the processes for both the on-time and off-time zones simultaneously. We use it to analyze the anomaly, which makes the resolution of inversion higher.