Symes, William W.2018-06-182018-06-181999Symes, William W.. "All Stationary Points of Differential Semblance Are Asymptotic Global Minimizers: Layered Acoustics." (1999) <a href="https://hdl.handle.net/1911/101915">https://hdl.handle.net/1911/101915</a>.https://hdl.handle.net/1911/101915Differential semblance velocity estimators have well-defined and smooth high frequency asymptotics. A version appropriate for analysis of CMP gathers and layered acoustic models has no secondary minima. Its structure suggests an approach to optimal parametrization of velocity models.21 ppengTechnical reportTR99-09