paul@sep.stanford.edu, biondo@sep.stanford.edu

## ABSTRACTWe analyze the amplitude variation as a function of reflection angle (AVA) for angle-domain common image gathers (ADCIG) produced via wave-equation migration. Straightforward implementations of the two main ADCIG methods lead to contradictory, thus inaccurate, amplitude responses. The amplitude inaccuracy is related to the fact that downward-continuation migration is the adjoint of upward-continuation modeling, but it is only a poor approximation of its inverse. We derive the frequency-wavenumber domain diagonal weighting operators that make migration a good approximation to the inverse of modeling. With these weights, both ADCIG methods produce consistent results. The main applications that follow from this paper are true-amplitude migration and pseudo-unitary modeling/migration, usable for iterative inversion. The two most important factors that degrade the accuracy of wave-equation ADCIGs are the limited sampling and offset range, combined with the band-limited nature of seismic data. |

- Introduction
- Modeling and migration amplitudes
- Applications of amplitude-preserved migration
- ADCIG methods
- Sources of inaccuracy
- Transformation Jacobians
- Jacobian for Common-azimuth migration
- Variable-velocity Jacobians
- Real Data
- Conclusions
- REFERENCES
- About this document ...

4/30/2001