Sampling Design of Synthetic Volume Arrays for Three-Dimensional Microwave Imaging

Abstract

In this paper, sampling design of three-dimensional (3-D) synthetic array (i.e., synthetic volume array) for microwave imaging is considered. Generally, the spatial sampling criteria for one-or two-dimensional arrays can be determined based on some narrowband/ultrawideband array theories. However, for 3-D arrays, where antennas are located in a volume instead of over a surface, these existing array theories are no longer straightforwardly applicable. To address the spatial sampling problem of 3-D arrays, we formulate it as a sensor/observation selection problem in this paper. Although some selection approaches exist and are conveniently applicable to small-scale problems, they are either less efficient or provide less optimal results for selection problems with data dimensions of hundreds or even thousands which is typical for microwave imaging. To get the (near-) optimal spatial sampling scheme for 3-D arrays, a greedy algorithm named clustered maximal projection on minimal eigenspace (CMPME) is proposed to select the most informative sampling positions based on some optimality criteria. This algorithm attempts to select the fewest sampling positions by considering an error threshold for the estimated images. Moreover, it has higher computational efficiency compared to the existing approaches. Finally, its effectiveness and selection performances are demonstrated through some imaging examples.

A PSF Approach to Far Field Discretization for Conformal Sources

“…While in [1] a statistical framework including general constraints is adopted for a linear operator, convex optimization algorithms are also employed as, for instance, in [2]. Microwave imaging may involve a huge amount of data and require different approaches such as the ones based on projection methods [3]. In any case, a model-driven strategy, founded on the mathematical properties of the kernel of the relevant imaging operator and on a priori knowledge about the investigation domain may lead to more effective results.…”

Optimal Field Sampling of Arc Sources via Asymptotic Study of the Radiation Operator

“…The question of sampling the field radiated by a source or the one scattered by an object is a classical research topic of the electromagnetics literature [1][2][3][4][5][6][7][8][9].…”

Scattered Far-Field Sampling in Multi-Static Multi-Frequency Configuration

“…This, however, presents a combinatorial complexity which can be difficult to deal with in practice. For this reason, several different approximate methods have been proposed in the literature [ 17 , 18 , 19 , 20 , 21 ]. All these methods select the measurement points by iterative procedures that attempt to optimize some metrics related to the singular values of the scattering operator.…”