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射线类正演方法以其高效,灵活的特点,在复杂地区的勘探中发挥着非常重要的作用.常规射线正演方法只考虑地震波的运动学特征,精度较低,且对复杂构造适应性较差;高斯射线束正演方法作为常规射线正演方法的一种改进,同时考虑地震波的运动学和动力学特征,且无需两点射线追踪,兼具计算效率和精度;菲涅尔束正演模拟进一步从波动理论角度对高斯射线束的有效半宽度进行了限制,改进了波场模拟的精度和稳定性.对三种射线类正演模拟方法进行理论解剖和分析,在高斯射线束正演方法的基础上,用第一菲涅尔带半径约束高斯束束宽实现了菲涅尔束正演算法.基于理论模型和实际模型,对三种射线类正演方法和波动方程有限差分法进行对比分析,结果表明高斯射线束正演方法具有较高的计算精度;菲涅尔束正演方法更加稳定,精度更高,更接近于波动方程有限差分方法.高斯射线束和菲涅尔束均具有较高的计算效率,适合于对波场模拟精度不高但对运算效率有较高要求的应用环境.
Radial forward modeling plays a very important role in the exploration of complex areas because of its high efficiency and flexibility.Routine ray forward modeling only considers the kinematics of seismic waves with low accuracy and is more adaptable to complex structures Gaussian beam forward method as an improvement of conventional ray forward method, taking into account the kinematics and dynamics of seismic wave characteristics, and without two ray tracing, both with computational efficiency and accuracy; Fresnel beam forward The simulation further limits the effective half-width of the Gaussian beam from the perspective of wave theory and improves the accuracy and stability of the wavefield simulation.The theoretical analysis and analysis of three kinds of ray forward modeling methods are carried out, Method, the Fresnel beam forward algorithm is realized with the first Fresnel zone radius-constrained Gaussian beamwidth.According to the theoretical model and the actual model, the three kinds of ray forward method and the wave equation finite difference method The results show that the forward modeling method of Gaussian beam has high accuracy. Fresnel beam forward modeling method is more stable and accurate, which is closer to the finite difference of wave equation The method of Gaussian beam and a Fresnel beam has a higher efficiency, but adapted to the requirements of the application of the operational environment of a high efficiency wave field simulation accuracy.