Abstract
Data-processing methods only considering the turn-off ramp in
transmitting waveforms are well established for land-based transient
electromagnetic (TEM) methods. The turn-on ramp effects on late-time
responses are generally neglected by data-processing methods. Our
forward-modeling results of homogeneous half-space models show that the
full-waveform effect which includes both effects caused by turn-on and
turn-off stages is common for a wide range of conductivities. The
inversion results for synthetic and field examples illustrate that the
inversion algorithm which does not consider the full-waveform effects
can lead to a higher resistivity in deeper parts of recovered models
compared with the true model. Therefore, it is of vital importance to
account for the full waveform effects in both forward modeling and
inversion algorithms. We use synthetic examples to show how our
inversion algorithms can improve the recovered model, and use real-data
examples to show the importance of incorporating full transmitting
waveforms in data-processing procedures.