局部时频变换横向约束Q值估计方法

Q estimation with lateral constraint based on local time-frequency transform

针对传统的频谱比法求取Q值存在噪声、反射相干和变换窗口等引起的算法不稳定问题,提出了一种基于局部时频变换的横向约束Q值估计方法。局部时频变换通过最小平方反演得到光滑的局部时频谱,为Q值估计提供了较好的时频谱值。在局部时频变换基础上,引入横向约束项,约束Q值在横向空间光滑变化,利用最小平方反演理论建立了横向空间约束的频谱比值计算方法。与传统的频谱比值法相比,局部时频变换横向约束Q值估计方法得到的结果更为准确。数值模拟及实际资料处理均验证了该方法的有效性。

Q estimation with the spectrum ratio is usually unstable due to noise, coherent reflection and transform window. To overcome this problem, we propose a method for Q estimation with lateral constraint based on local time frequency transform. Local time-frequency transform is obtained by the least square inversion method to get a smooth local time spectrum, which provides a good time frequency spectrum for Q estimation. On the basis of local time-frequency transform, we introduce lateral constraint, limit lateral smooth variation of Q value, and establish a novel method for calculating the spectrum ratio using the least square inversion theory. Compared with the conventional spectral ratio method, results obtained by the proposed method are more accurate. Numerical simulation and real data processing show that the proposed method is effective. © 2016, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.