arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1908.01479eess.IVcs.LGcs.NAmath.NAphysics.comp-ph
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使用高度不完整和损坏的数据进行成像

Imaging with highly incomplete and corrupted data

Miguel Moscoso, Alexei Novikov, George Papanicolaou, Chrysoula Tsogka

摘要:

我们考虑的问题,从一些嘈杂的数据使用$l_1$ -最小化方法成像稀疏场景。该问题可以被转换为形式为$A \, ρ=b$的线性系统,其中$A$是$N\times K$测量矩阵。我们假设未知稀疏向量$ρ\in {\mathbb{C}}^K$的维数远大于数据向量$b \in {\mathbb{C}}^N$的维数,即$K \gg N$。我们提供了一个理论框架,使我们能够检查在什么条件下的$\ell_1$ -最小化问题承认一个解决方案,是接近的确切存在的噪声。我们的分析表明,当需要高分辨率时,$l_1$ -最小化对于具有噪声数据的成像是不稳健的。为了提高性能的$l_1$ -最小化,我们建议,而不是解决增广线性系统$ [A \, | \, C] ρ=b$,其中的$N \times Σ$矩阵$C$是一个噪声收集器。它被构造成使得其列向量提供了一个框架,在该框架上,可以很好地近似数据的噪声(维度$N$的向量)。理论上,噪声收集器的尺寸$Σ$应该是$e^N$,这将使其使用不实用。然而,我们的数值结果表明,在噪声的存在下,可以得到强大的结果与足够大的列数$Σ\approx 10 K$。

英文摘要:

We consider the problem of imaging sparse scenes from a few noisy data using an $l_1$-minimization approach. This problem can be cast as a linear system of the form $A \, ρ=b$, where $A$ is an $N\times K$ measurement matrix. We assume that the dimension of the unknown sparse vector $ρ\in {\mathbb{C}}^K$ is much larger than the dimension of the data vector $b \in {\mathbb{C}}^N$, i.e, $K \gg N$. We provide a theoretical framework that allows us to examine under what conditions the $\ell_1$-minimization problem admits a solution that is close to the exact one in the presence of noise. Our analysis shows that $l_1$-minimization is not robust for imaging with noisy data when high resolution is required. To improve the performance of $l_1$-minimization we propose to solve instead the augmented linear system $ [A \, | \, C] ρ=b$, where the $N \times Σ$ matrix $C$ is a noise collector. It is constructed so as its column vectors provide a frame on which the noise of the data, a vector of dimension $N$, can be well approximated. Theoretically, the dimension $Σ$ of the noise collector should be $e^N$ which would make its use not practical. However, our numerical results illustrate that robust results in the presence of noise can be obtained with a large enough number of columns $Σ\approx 10 K$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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