Inverse problems arising in microwave imaging suffer from high ill-posedness. As it is well known, necessary to employ regularized inversion methods, order mitigate such behavior. Usually, approaches are formulated standard Hilbert spaces. Recently, a more generic regularization theory, working Banach spaces, has been investigated, overcome some limitations of the Hilbert-space regularization. In this paper, novel algorithm, performing L <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

A conjugate-gradient-based regularization technique in L <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</sup> Banach spaces, conjunction with an inexact-Newton solving scheme, is presented this paper. The proposed method applied to obtain the reconstruction of dielectric properties human tissues hemorrhagic brain stroke microwave imaging. obtained by a nonlinear inverse problem, starting from set scattered-field measurements. numerical...

This article describes a microwave tomographic approach for the quantitative imaging of brain stroke inside human head. For acquisition scattered-field information, prototype multistatic system is adopted. An array custom antennas placed in contact with head, and switching matrix used to measure scattering parameters each pair probes. The collected data are processed by an inversion method based on variable-exponent Lebesgue-space regularization technique, whose outcome map dielectric...

Anti-reflective boundary conditions (BCs) have been introduced recently in connection with fast deblurring algorithms. In the noise free case, it has shown that they substantially reduce artefacts called ringing effects respect to other classical choices (zero Dirichlet, periodic, reflective BCs) and lead O(n2log(n)) arithmetic operations, where n2 is size of image. one-dimensional for noisy data, we proposed a successful approach re-blurring: more specifically, when PSF symmetric, normal...

An electromagnetic inverse scattering approach for imaging of shallow subsurface objects is reported. It extends to multifrequency processing, an efficient method previously developed single frequency imaging. The considered iterative procedure based on inexact-Newton in L Banach spaces, which exhibits effective regularization capabilities and reduced over-smoothing effects. validated using numerical simulations cylindrical scatterers are reconstructed a homogeneous lossy medium. Results...

A reconstruction technique, mathematically based on a generalization of the gradient method in Banach spaces, is first proposed to enhance spatial resolution radiometer earth observation measurements. This approach allows reducing over-smoothing effects and oscillations that are often present standard Hilbert-spaces procedures without any drawback numerical complexity. Experiments undertaken data set consisting both simulated actual 2-D special sensor microwave imager measurements show...

An innovative nonlinear inverse scattering approach in variable exponent Lebesgue spaces is proposed for microwave imaging purposes. The main objective of the to overcome one problems associated with reconstruction procedures developed constant exponent, i.e., need selection optimum Lebesgue-space norm parameter, which critical obtaining accurate reconstructions, and no exact rules exist this choice. paper oriented tomographic applications at frequencies, adopted inversion procedure based on...

A new approach to noninvasive inspection of dielectric targets at microwave frequencies is proposed. Cylindrical objects are reconstructed under the second-order Born approximation. multi-illumination configuration considered. The continuous model discretized by moment method and an efficient inexact-Newton applied. profile iteratively starting from measured scattered data, which related unknown target through inverse scattering equations written in a variational setting. Several numerical...

An approach to solve the inverse scattering problem for imaging applications is presented. The proposed algorithm based on an inexact Newton method applied Lippmann-Schwinger integral equation. Inhomogeneous dielectric scatterers with high contrast in a tomographic arrangement are considered. capabilities of assessed reference several different unknown objects. In particular, both noisy synthetic data and experimental have been used. Furthermore, comparison model second order Born...

A simple innovation that enables a faster convergence rate of iterative gradient-like descent approaches is proposed and applied to linear image reconstruction problems from irregular sampling. The key idea reduce the amount regularization effects conventional Tikhonov functional by introducing negative seminorm penalty term, whose role speed up without reducing accuracy. method employed enhance spatial resolution microwave remotely sensed products. First experiments, undertaken on simulated...

An overview of the recent advancements in development microwave imaging procedures based on exploitation regularization theory Lebesgue spaces is reported this paper. Such inversion schemes have been found to provide accurate results several scenarios, thanks different geometrical properties that can exhibit with respect more classical Hilbert ones. Moreover, extension general case variable-exponent also addressed. Experimental involving reference data are shown for supporting theoretical...

Brain injuries represent a critical situation, where both detection and monitoring should be quick accurate at the same time. Microwave techniques are thus gaining attention in diagnostic process of these diseases. However, inhomogeneities variations inside human brain by using electromagnetic fields microwave frequencies is very challenging inverse problem. An innovative hybrid imaging method introduced this contribution, which combines benefits fast qualitative processing technique with an...

A phaseless tomographic method for microwave imaging is presented in this article. The developed algorithm aims at retrieving the distributions of dielectric properties a predefined region under test, starting from amplitude-only electric field measurements. use kind input data allows cheaper measurement setups that do not require coherent detection or complex phase synchronization approaches. Inside procedure, nonlinear relationship between measured and targets inverted by using an...

A novel two-step inverse-scattering technique is proposed for through-the-wall microwave imaging. The approach based on a regularization scheme developed in the framework of variable-exponent Lebesgue spaces, which enhances quality reconstruction by properly tuning exponent function that defines adopted norm. Such built directly from available data using beamforming delay-and-sum scheme. After an initial numerical assessment, validated against experimental measurements laboratory...

Off-the-grid regularisation has been extensively employed over the last decade in context of ill-posed inverse problems formulated continuous setting space Radon measures M(Ω) . These approaches enjoy convexity and counteract discretisation biases as well numerical instabilities typical their discrete counterparts. In framework sparse reconstruction point (sum weighted Diracs), a Total Variation norm is typically combined with an L2 data term modelling additive Gaussian noise. To assess...

In the area of biomedical diagnostics, microwave imaging techniques have been recently proposed for performing brain stroke detection and monitoring. Indeed, theoretically, these make it possible to meet timeliness requirements such a diagnosis with portable systems. Moreover, relying on use microwaves, they are noninvasive allow continuous monitoring critical patients. this paper, problem is solved by exploiting multifrequency data an inexact-Newton method formulated in framework...

The imaging of buried objects is a challenging topic in electromagnetic research. In this letter, method previously proposed for scatterers free-space extended to the case lossy half-space. approach based on solution underlying inverse-scattering problem within second-order Born approximation by means two-step inexact-Newton algorithm. capabilities and limitations are evaluated some numerical simulations. Furthermore, comparisons with also reported

In this paper, a new computer-time effective iterative method is proposed to enhance the spatial resolution of microwave radiometer data in both Hilbert and Banach spaces. The reconstruction based on conjugate gradient (CG) method. CG well-known electromagnetics, where it commonly used address inverse problems However, has never been applied related enhancement remotely sensed measurements. adapted case exploited reconstruct brightness field at enhanced resolution. Then, is, for first time,...

Abstract Electromagnetic inspection techniques are becoming powerful tools for buried object detection and subsurface prospection in several applicative fields, such as civil engineering archeology. However, the nonlinearity ill‐posedness of underlying inverse problem make development efficient imaging a very challenging task. In present paper, an algorithm based on regularizing approach L p Banach spaces is proposed tackling problems. The effectiveness verified by means numerical...

A recently proposed inverse scattering method is assessed against some of the real input data measured by Institut Fresnel (Marseille, France). The based on application an inexact-Newton to Lippmann–Schwinger integral equation problem within second-order Born approximation. localization and shaping capabilities approach are evaluated considering reconstruction multiple dielectric cylinders. approximated inhomogeneous cross sections also quantified.

In this paper, a new inverse-scattering-based reconstruction method is presented. The aim of the approach to "invert" wavefleld samples, which are collected by experimental tomographic systems working at radio frequencies and microwaves. Imaging operating in band require solution nonlinear highly ill-posed inverse problem. need regularize problem addressed here considering an efficient inexact Newton that able inspect strong scatterers. mathematical formulation detailed discussed. Moreover,...

The Landweber method is a simple and flexible iterative regularization algorithm, whose projected variant provides nonnegative image reconstructions. Since the usually very slow, we apply circulant preconditioners, exploiting shift invariance of many deblurring problems, in order to accelerate convergence. This way reasonable reconstructions can be obtained within few iterations; becomes competitive more robust than other approaches that, although faster, sometimes lead lower accuracy. Some...