Wave equation tomographic velocity inversion method based on the Born/Rytov approximation

基于Born/Rytov近似的波动方程层析速度反演方法研究(英文)

This paper discusses Born/Rytov approximation tomographic velocity inversion methods constrained by the Fresnel zone. Calculations of the sensitivity kernel function and traveltime residuals are critical in tomographic velocity inversion. Based on the Bom/Rytov approximation of the frequency-domain wave equation, we derive the traveltime sensitivity kemels of the wave equation on the band-limited wave field and simultaneously obtain the traveltime residuals based on the Rytov approximation. In contrast to single-ray tomography, the modified velocity inversion method improves the inversion stability. Tests of the near- surface velocity model and field data prove that the proposed method has higher accuracy and Computational efficiency than ray theory tomography and full waveform inversion methods.

本文研究了第一菲涅尔带约束下的波动方程Born/Rytov近似层析反演方法,其中如何求取敏感核函数和旅行时残差是关键技术。以频率域波动方程Born和Rytov近似为基础,推导出建立在带限地震波理论基础上的波动方程Born/Rytov近似走时敏感核函数,同时依据Rytov近似求取走时残差。与常规单射线走时层析方法不同,改进的速度反演方法提高了反演的稳定性。模型试算与实际资料处理结果表明,相对于传统的单射线走时层析和波形反演方法,该方法具有更高的反演精度与计算效率。