Full-wavefield estimation of angle-dependent reflectivity and migration velocity

Abstract

The joint migration inversion (JMI) approach is a very robust and effective method for simultaneously estimating reflectivity (imaging) and the propagation velocity model in a closed-loop process. Being a full waveform method, it utilizes multiple scattering for estimating both types of parameters. Usually, angle-independent reflectivity and velocity are estimated in a ”flip-flop” manner based on gradient descent scheme. Two new features are discussed in this paper. First, simultaneous estimation of angle-dependent reflectivity in the JMI framework is studied, which allows to handle data with strong amplitude versus offset (AVO) variations. Second, a quasi-Newton algorithm was tested to estimate both angle-independent and angle-dependent reflectivity. The method is demonstrated on numerical data, generated by it’s own forward modelling method, as well as data generated using finite difference modeling.