论文标题
贝叶斯的方法与拓扑先验的反向散射
Bayesian approach to inverse scattering with topological priors
论文作者
论文摘要
我们提出了一个贝叶斯推理框架,以估计反向散射问题的不确定性。鉴于观察到的数据,正向模型及其不确定性,我们在代表对象的有限参数字段上找到了后验分布。为了构建先前的分布,我们使用拓扑灵敏度分析。我们证明了贝叶斯解决方案在光和声性全息图中具有合成数据的方法。通过对后部分布进行采样,提取了有关其中心位置,直径大小,方向和材料特性之类的对象的统计信息。假设已经知道的对象数量,则比较马尔可夫链蒙特卡洛采样获得的结果,并通过对线性化发现的高斯分布进行采样,围绕最大后验估计显示合理的一致性。后一个程序的计算成本较低,这使其成为3D不确定性研究的有趣工具。但是,MCMC采样提供了后验分布的更完整的图像,并产生多模式后分布,以解决较大的测量噪声问题。当对象数量未知时,我们将设计一个随机模型选择框架。
We propose a Bayesian inference framework to estimate uncertainties in inverse scattering problems. Given the observed data, the forward model and their uncertainties, we find the posterior distribution over a finite parameter field representing the objects. To construct the prior distribution we use a topological sensitivity analysis. We demonstrate the approach on the Bayesian solution of 2D inverse problems in light and acoustic holography with synthetic data. Statistical information on objects such as their center location, diameter size, orientation, as well as material properties, are extracted by sampling the posterior distribution. Assuming the number of objects known, comparison of the results obtained by Markov Chain Monte Carlo sampling and by sampling a Gaussian distribution found by linearization about the maximum a posteriori estimate show reasonable agreement. The latter procedure has low computational cost, which makes it an interesting tool for uncertainty studies in 3D. However, MCMC sampling provides a more complete picture of the posterior distribution and yields multi-modal posterior distributions for problems with larger measurement noise. When the number of objects is unknown, we devise a stochastic model selection framework.