Real-Time Multiview SAR Imaging Using a Portable Microwave Camera With Arbitrary Movement

Abstract

This paper presents the first demonstrator of a portable, multi-view, high-resolution, three-dimensional (3D) and real-time microwave imaging system. The system is based on a recently-developed real-time 3D microwave camera, which performs quasi-monostatic acquisitions, equipped with an optical depth camera providing target surface profile information. Additionally, the entire system can be arbitrarily moved along the target performing microwave and depth camera synchronized acquisitions from different views with a twofold purpose, namely; a) enabling a coverage area much larger than that possible with a static imaging system, and b) allowing for incorporation of several tilt angles (or views) to enhance capturing specular reflection imaging data to improve the overall image quality. At each scanning position, the imaging data from the microwave camera are processed to build a local 3D microwave image. The information is then merged, using recently-proposed techniques for multi-view synthetic aperture imaging, to compose the global image. The synchronized optical camera depth acquisitions enable tracking the entire imager movements so that the position and attitude are known. Moreover, the data acquired by the depth camera are also use to build a complementary 3D outer surface profile model of the target, producing a combined and realistic image of the internal and external geometries of the target. Finally, the performance of the combined system is evaluated using several examples related to hidden contraband covered by clothing (i.e., people screening).

Multi-Layered Circular Dielectric Structures’ Synthetic Aperture Radar Imaging Based on Green’s Function Using Non-Uniform Measurements

“…Therefore, the frequency band selection should be performed, considering the tradeoff between imaging resolution and penetration capabilities and the specific requirements of the practical applications of interest. Despite these powerful approaches for uniform data, last advances in electromagnetic imaging have shown that the use of portable scanners, driven by hand, can be useful for a large number of applications, including electromagnetic compatibility [15], people screening [16], or nondestructive evaluation [17]. However, these systems do not provide equally-spaced acquisition points.…”

“…The position of the non-uniform measurement points can be recorded by means of affordable systems, such as depth-cameras [16] or motion capture systems [15,17]. Thus, the above problem becomes how to design the multi-layered C-SAR imaging algorithm once the non-uniform measurement points are known.…”

A Microwave Sensing and Imaging Method for Multiphase Flow Metering of Crude Oil Pipes

“…Microwave sensing and imaging (MSI) is a noninvasive method for investigating internal structural properties [17]. Ultrawideband (UWB) synthetic aperture radar (SAR) technology can provide a high-resolution 2-D image in the range and cross-range directions [18], [19].…”

Review of Active Millimeter Wave Imaging Techniques for Personnel Security Screening

“…To resolve the conflict between compactness requirements in applications and mannequin-size FOV as well as reasonable cross-range resolution, portable imaging systems combining mmW imaging and other auxiliary techniques, such as an optical camera and a positioning system, are proposed [33], [34]. A portable mmW imaging system based on the monostatic SAR and the optical depth camera was proposed by Laviada et al [33], as shown in Fig. 11 (a).…”

“…To resolve the conflict between compactness requirements in applications and mannequin FOV as well as reasonable cross-range resolution, the portable imaging systems combing mmW imaging and optical camera or positioning system are proposed after 2017 [33], [34]. With the spatial information provided by the optical auxiliary systems, the compact aperture is equivalently synthesized to produce a large effective aperture, and the multiple frames are fused together for reconstructing the image.…”