Anisotopic Gaussian Beam Imaging of Walk-away VSP Data

The approach to true amplitude seismic imaging in anisotopic media for walk-away Vertical Seismic Profile (VSP) multi component data is presented and discussed. This approach is migration procedure based on weighted summation of prestack data. True amplitude weights are computed with application of Gaussian beams (GB). We shoot a couple of properly chosen GB with fixed dip and opening angles from the current imaging point towards acquisition system. This couple of beams is used in order to compute true amplitude selective image of the rapid velocity variation. The total true amplitude image is constructed by superposition of selective ones being computed for a range of available dip angles. The global regularity of Gaussian beams permits one not take care of, is the ray field regular or not. The use of P- and S-wave Gaussian beams provides the possibility to handle raw multi component data without of their preliminary separation to PP and PS waves. The use of anisotopic Gaussian beams allows to take into account anisotropy of the background model.