… extended image as virtual sources in the subsurface offset domain, … in the position of the
virtual sources from zero offset to … For isotropic and anisotropic migration velocity analysis, we …

… or ‘wave equation’) variants of prestack depth migration, … this paper and are highly automated
in current industry practice. … subsurface vector half‐offset h (note: not the same as source‐…

… evaluate the focusing of the prestack image in the subsurface-offset … In shot-profile migration,
source wavefields D and receiver … Our method is fully automated and picking-free. The grid-…

… prestack depth migration and full waveform inversion. Wave equation migration velocity
analysis (WEMVA) utilizes band-limited waveform to invert the velocity in an automatic manner. …

… (WEMVA) is a more robust automatic velocity tomography … By measuring the flatness or
focusing of the CIGs, we can … when we use a lower velocity, a 2D subsurface angle gather shows …

… wave-equation migration, the failure of the migration to focus the image volume in (subsurface)
offset is an index of velocity … geometry to be continuous (in source and receiver position), …

… The source extrapolation step in wave-equation prestack … We did not automate it as we
wished to focus on the central … because all possible paths are automatically generated. Figure 12 …

… Since time reversal is by nature a full wave-equation method, … to obtain a VS at any
subsurface point where we do not … Another major advantage is the automatic correction for time-…

… if the energy focuses around the zero-subsurface offset. Because … are a solution of the wave
equation for a source term excited by the … This is an automatic way to compensate for uneven …

… actual background velocity, and the virtual sources explode with … -shot migration, energy
nicely focuses at zero subsurface offset (… is a standard and almost entirely automated procedure. …