The analysis of surface wave dispersion curves is a way to infer the vertical distribution of shear-wave velocity. The range of applicability is extremely wide going, for example, from seismological studies to geotechnical characterizations and exploration geophysics. However, the inversion of the dispersion curves is severely ill-posed and only limited efforts have been put into the development of effective regularization strategies. In particular, relatively simple smoothing regularization terms are commonly used, even when this is in contrast with the expected features of the investigated targets. To tackle this problem, stochastic approaches can be utilized, but they are too computationally expensive to be practical, at least, in the case of large surveys. Instead, within a deterministic framework, we evaluate the applicability of a regularizer capable of providing reconstructions characterized by tunable levels of sparsity. This adjustable stabilizer is based on the minimum support regularization, applied before on other kinds of geophysical measurements, but never on surface wave data. We demonstrate the effectiveness of this stabilizer on i) two benchmark - publicly available - datasets at crustal and near-surface scales, ii) an experimental dataset collected on a well-characterized site. In addition, we discuss a possible strategy for the estimation of the depth of investigation. This strategy relies on the integrated sensitivity kernel used for the inversion and calculated for each individual propagation mode. Moreover, we discuss the reliability, and possible caveats, of the direct interpretation of this particular estimation of the depth of investigation, especially in the presence of sharp boundary reconstructions.

中文翻译：

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从表面波数据重建具有可调稀疏度的剪切波速度剖面

分析表面波频散曲线是一种推论横波速度垂直分布的方法。例如，从地震研究到岩土工程表征和勘探地球物理学，其适用范围极为广泛。但是，色散曲线的倒置严重不适，仅对有效的正则化策略的开发进行了有限的努力。特别是，即使与被研究目标的预期特征相反，通常也使用相对简单的平滑正则化项。为了解决这个问题，可以使用随机方法，但是它们在计算上过于昂贵，至少在大型调查的情况下不可行。相反，在确定性框架内，我们评估了能够提供以可调稀疏度为特征的重建的正则化器的适用性。这种可调节的稳定器基于最小支撑正则化，该最小化正则化之前曾应用于其他类型的地球物理测量，但从未应用于表面波数据。我们在以下方面证明了这种稳定剂的有效性：i）两个基准（可公开获得）在地壳和近地表尺度的数据集，ii）在特征明确的站点上收集的实验数据集。此外，我们讨论了估计调查深度的可能策略。该策略依赖于用于反演并针对每个单独的传播模式进行计算的集成灵敏度内核。此外，我们讨论了可靠性以及可能的警告，