In airborne time-domain EM (ATEM) the signal-to-noise ratio (SNR) is paramount for the detection of small responses from discrete conductors. In this paper it is examined how shortening the linear current turn-off can enhance the target responses significantly for discrete 3D conductors. For the objective of the paper two methods were applied (1) synthetic 2D thin sheet modelling as approximations to 3D discrete conductors and (2) comparison of real datasets collected over discrete conductors using two different ATEM systems having respectively a 200 s and a 1,200 s turn-off ramp. The findings of both the synthetic modelling and the real datasets show that the target response can be amplified by a factor 2 or even more if the length of the current turn-off ramp is shortened from 1,200 s to 200 s. The enhancement of the target response, and thereby the SNR, occurs for a large group of discrete conductors for which the time constant is comparable to or smaller than the duration of the current turn-off ramp. Shortening the current turn-off ramp will improve the capability to detect such conductors.


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