A method, comprising: obtaining, by a computer processor, a sonic waveform (220, 228, 320) for each of a plurality of source and receiver positions along a borehole; obtaining, by the computer processor, a sonic wave propagation velocity of a target event for the plurality of source and receiver positions along the borehole; performing, by the computer processor, a linear moveout correction on the sonic waveforms (220, 228, 320) based, at least in part, on the sonic wave propagation velocity of the target event for the plurality of source and receiver positions along the borehole; stacking, by the computer processor, the linear moveout corrected sonic waveforms to generate a stacked waveform (346, 446) at the plurality of source and receiver positions along the borehole; determining, by the computer processor, a first arrival-time of the target event on the stacked waveform (346, 446) for each of the plurality of source and receiver positions along the borehole based, at least in part on an extremum of a first objective function based on the stacked waveforms (346, 446), wherein the first objective function comprises terms quantifying two or more of the semblance, phase consistency, energy ratio, and time-pick consistency, between one or more reference stacked waveforms and the stacked waveform (346, 446); predicting, by the computer processor, a candidate arrival-time of the target event for the sonic waveform (220, 228, 320) at the plurality of source and receiver positions based, at least in part, on the first arrival-time of the target event on the stacked waveform (346, 446) for the plurality of positions, and the sonic wave propagation velocity of the target event for the plurality of source and receiver positions within the borehole; and determining, by the computer processor, a second arrival-time for the target event on the sonic waveform (220, 228, 320) at the plurality of source and receiver positions within the borehole based, at least in part on the candidate arrival-time of the target event and an extremum of a second objective function (554, 654), wherein the second objective function (554, 654) comprises terms quantifying two or more of the semblance, phase consistency, energy ratio, and time-pick consistency, between one or more reference sonic waveforms and the sonic waveform (220, 228, 320). obtaining, by a computer processor, a sonic waveform (220, 228, 320) for each of a plurality of source and receiver positions along a borehole; obtaining, by the computer processor, a sonic wave propagation velocity of a target event for the plurality of source and receiver positions along the borehole; performing, by the computer processor, a linear moveout correction on the sonic waveforms (220, 228, 320) based, at least in part, on the sonic wave propagation velocity of the target event for the plurality of source and receiver positions along the borehole; stacking, by the computer processor, the linear moveout corrected sonic waveforms to generate a stacked waveform (346, 446) at the plurality of source and receiver positions along the borehole; determining, by the computer processor, a first arrival-time of the target event on the stacked waveform (346, 446) for each of the plurality of source and receiver positions along the borehole based, at least in part on an extremum of a first objective function based on the stacked waveforms (346, 446), wherein the first objective function comprises terms quantifying two or more of the semblance, phase consistency, energy ratio, and time-pick consistency, between one or more reference stacked waveforms and the stacked waveform (346, 446); predicting, by the computer processor, a candidate arrival-time of the target event for the sonic waveform (220, 228, 320) at the plurality of source and receiver positions based, at least in part, on the first arrival-time of the target event on the stacked waveform (346, 446) for the plurality of positions, and the sonic wave propagation velocity of the target event for the plurality of source and receiver positions within the borehole; and determining, by the computer processor, a second arrival-time for the target event on the sonic waveform (220, 228, 320) at the plurality of source and receiver positions within the borehole based, at least in part on the candidate arrival-time of the target event and an extremum of a second objective function (554, 654), wherein the second objective function (554, 654) comprises terms quantifying two or more of the semblance, phase consistency, energy ratio, and time-pick consistency, between one or more reference sonic waveforms and the sonic waveform (220, 228, 320).