A New Wave Equation Based Source Location Method with Full-waveform Inversion

Abstract

SummaryLocating the source of a passively recorded seismic event is still a challenging problem, especially when the velocity is unknown. Many imaging approaches to focus the image do not address the velocity issue and result in images plagued with illumination artifacts. We develop a waveform inversion approach with an additional penalty term in the objective function to reward the focusing of the source image. This penalty term is relaxed early to allow for data fitting, and avoid cycle skipping, using an extended source. At the later stages the focusing of the image dominates the inversion allowing for high resolution source and velocity inversion. We also compute the source location explicitly and numerical tests show that we obtain good estimates of the source locations with this approach.

Microseismic Event Estimation Based on an Efficient Wavefield Inversion

“…To further improve FWI-based methods in microseismic, a source-independent FWI method was introduced to invert for the velocity model and the source components [15]. In the frequency domain, a source-extension approach was proposed to determine the source location while inverting for the velocity and source image, simultaneously [16]. To further improve this method, using the multiscattered energy in the data is able to provide better illumination to the velocity model when low frequencies in the data are missing [17].…”