Steininger Gavin, Dosso Stan E, Holland Charles W, Dettmer Jan
School of Earth and Ocean Sciences, University of Victoria, Victoria, BC V8W 3P6, Canada.
Applied Research Laboratory, The Pennsylvania State University, State College, Pennsylvania 16804-0030.
J Acoust Soc Am. 2014 Oct;136(4):1563-73. doi: 10.1121/1.4892787.
This paper presents a polynomial spline-based parameterization for trans-dimensional geoacoustic inversion. The parameterization is demonstrated for both simulated and measured data and shown to be an effective method of representing sediment geoacoustic profiles dominated by gradients, as typically occur, for example, in muddy seabeds. Specifically, the spline parameterization is compared using the deviance information criterion (DIC) to the standard stack-of-homogeneous layers parameterization for the inversion of bottom-loss data measured at a muddy seabed experiment site on the Malta Plateau. The DIC is an information criterion that is well suited to trans-D Bayesian inversion and is introduced to geoacoustics in this paper. Inversion results for both parameterizations are in good agreement with measurements on a sediment core extracted at the site. However, the spline parameterization more accurately resolves the power-law like structure of the core density profile and provides smaller overall uncertainties in geoacoustic parameters. In addition, the spline parameterization is found to be more parsimonious, and hence preferred, according to the DIC. The trans-dimensional polynomial spline approach is general, and applicable to any inverse problem for gradient-based profiles. [Work supported by ONR.].
本文提出了一种基于多项式样条的跨尺度地声反演参数化方法。该参数化方法在模拟数据和实测数据中均得到了验证，结果表明它是一种有效表示以梯度为主的沉积物地声剖面的方法，这种剖面通常出现在例如泥泞海床等情况中。具体而言，在马耳他高原一个泥泞海床实验场地测量的海底损失数据反演中，使用偏差信息准则（DIC）将样条参数化与标准的均匀层堆叠参数化进行了比较。DIC是一种非常适合跨尺度贝叶斯反演的信息准则，本文将其引入到地声学中。两种参数化方法的反演结果与在该场地提取的沉积物岩芯测量结果吻合良好。然而，样条参数化能更准确地解析岩芯密度剖面的幂律结构，并在地声参数方面提供更小的总体不确定性。此外，根据DIC发现样条参数化更简洁，因此更受青睐。跨尺度多项式样条方法具有通用性，适用于任何基于梯度剖面的反问题。[由美国海军研究办公室资助。]
