Migration velocity analysis using a ray method asymptotics of the double square root equation

N. N. Shilov^a, A. A. Duchkov<sup>b

a</sup> Novosibirsk State University, Novosibirsk, 630090 Russia
^b A. A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk

Abstract: Seismic images of subsurface structures are the most valuable outcome of seismic data processing. The image quality is strongly affected by the accuracy of background velocity model. In this paper, we develop a gradient-descent velocity update algorithm based on our original high-frequency asymptotics of the double square root equation, i. e., a special one-way approximation of the wave equation describing single-scattered wave field only. We propose a loss function consistent with widely adopted imaging condition and derive equations for its gradient computation. We test our method on noise-free synthetic datasets in 2D settings.

Keywords: seismic inverse problem, velocity analysis, double square root equation, ray method, perturbation theory.

UDC: 532.517.4

Received: 17.04.2023
Revised: 02.05.2023
Accepted: 07.06.2023

DOI: 10.33048/SIBJIM.2024.27.108

 English version: Journal of Applied and Industrial Mathematics, 2024, 18:1, 150–166