Two-dimensional dense seismic ambient noise array techniques have been widely used to image and monitor subsurface structure characterization in complex urban environments. It does not have limitations in the layout under the limitation of urban space, which is more suitable for 3D S-velocity imaging. In traditional ambient seismic noise tomography, the narrowband filtering (NBF) method has many possible dispersion branches. Aliases would appear in the dispersive image, and the dispersion curve inversion also depends on the initial model. To obtain high-accuracy 3D S-velocity imaging in urban seismology, we developed a robust workflow of data processing and S-velocity tomography for 2D dense ambient noise arrays. Firstly, differing from the NBF method, we adopt the continuous wavelet transform (CWT) as an alternative method to measure the phase velocity from the interstation noise cross-correlation function (NCF) without 2π ambiguity. Then, we proposed the sequential dispersion curve inversion (DCI) strategy, which combines the Dix linear inversion and preconditioned fast descent (PFD) method to invert the S-velocity structure without prior information. Finally, the 3D S-velocity model is generated by the 3D spatial interpolation. The proposed workflow is applied to the 2D dense ambient seismic array dataset in Changchun City. The quality evaluation methods include residual iteration error, horizontal-to-vertical spectral ratio (HVSR) map, and electrical resistivity tomography (ERT). All tests indicate that the developed workflow provides a reliable 3D S-velocity model, which offers a reference for urban subsurface space exploration.

二维密集地震环境噪声阵列技术已广泛用于复杂城市环境中的地下结构特征成像和监测。不受城市空间限制下的布局限制，更适合3D S速度成像。在传统的环境地震噪声层析成像中，窄带滤波（NBF）方法具有许多可能的色散分支。色散图像中会出现锯齿，色散曲线反演也取决于初始模型。为了在城市地震学中获得高精度 3D S速度成像，我们为 2D 密集环境噪声阵列开发了强大的数据处理和S速度层析成像工作流程。首先，与NBF方法不同，我们采用连续小波变换（CWT）作为替代方法，从站间噪声互相关函数（NCF）测量相速度，没有2π模糊度。然后，我们提出了顺序频散曲线反演（DCI）策略，该策略结合了Dix线性反演和预处理快速下降（PFD）方法，在没有先验信息的情况下反演S速度结构。最后，通过3D空间插值生成3D S速度模型。所提出的工作流程应用于长春市二维密集环境地震台阵数据集。质量评估方法包括残余迭代误差、水平垂直谱比（HVSR）图和电阻率层析成像（ERT）。所有测试表明，所开发的工作流程提供了可靠的3D S速度模型，为城市地下空间探索提供了参考。