An all electronic passive millimetre wave imaging system

Salmon, Neil A.; Beale, John; Beard, Andy; Dean, Mike; Hayward, S.D.; Hickling, Paul; Chiw, S.T.; Ghafouri‐Shiraz, H.; Hall, Peter; Macpherson, R. I.; Lewis, Rob; Lettington, Alan H.; Dunn, Dennis

doi:10.1117/12.608846

Cited by 5 publications

(3 citation statements)

References 3 publications

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“…Form (3) indicates that under the same range, the spatial resolution only depends on the maximal diameter of the synthetic aperture antenna; the imaging region size only depends on the minimal spatial interval of antenna array. From the view of optics, the quadratic phase factor is equivalent to a lens with focal length R, playing a phase compensation role between plane wave and spherical wave.…”

Section: Introductionmentioning

confidence: 99%

“…As MMW has the abilities of distinction metal object and the surroundings and certain penetration, it is greatly significant to develop MMW imaging technology for target recognition. Many works are made in MMW-SAR passive imaging technology [1][2][3][4][5][6][7], but those remote sensing types are not appropriate for near range passive imaging.…”

Section: Introductionmentioning

confidence: 99%

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Near range MMW synthetic aperture radiometer 3D passive imaging

Ben-qing

Qian

2008

2008 8th International Symposium on Antennas, Propagation and EM Theory

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Millimeter wave synthetic aperture radiometer (MMW-SAR) technology can use phase information of electromagnetic wave radiating from target, and will be real-time imaging with less receiver elements. However MMW-SAR is limited to 2D imaging due to passive regime nowadays, lack of range information of target, which is very unfavorable for target detection and identification, thus this paper presents novel principle and algorithm for MMW-SAR 3D passive imaging under near range conditions. In near range, it is spherical wave radiation and wave front curvature of spherical wave is inversely proportional to propagation distance, synthetic aperture technology can get the curvature of the wave front. Thus there is quadratic phase factor in imaging formula primarily. Regarding the factor as LFM, the 3D imaging algorithm calculates the slope of LFM so as to get wave front curvature, then calculated range distribution. MMW-SAR 3D passive imaging can get both range distribution and brightness temperature distribution, which could effectively overcome fuzzy problem caused by defocus. Index Items-Millimeter wave radiometer; synthetic aperture; near range; 3D passive imaging; FRFT I. INTRODUCTIONRadiometer is a high sensitive receiver that receipts weak energy radiation from object. MMW radiometer passive imaging technology has been widely applied in many fields. The imaging regime mainly includes focal plane array, phased array, interferometric synthetic aperture and mechanical scanning. As MMW has the abilities of distinction metal object and the surroundings and certain penetration, it is greatly significant to develop MMW imaging technology for target recognition. Many works are made in MMW-SAR passive imaging technology [1-7], but those remote sensing types are not appropriate for near range passive imaging.Near range MMW passive imaging technology is used for detection and identification target within several meters [8], for example medical imaging can detect lesions location of patients, security department can detect concealed weapons and the dangerous the like, traffic management can monitor vehicles, in addition navigation can land automatically under the adverse climatic conditions. In May 2007, an airport in Amsterdam hires a millimeter human security scanner, greatly simplifying the airport security procedures. A near range human body image with a hidden metal ring is shown in Fig. 1. In recent years, near range MMW-SAR passive imaging technology has been developed, and imaging prototypes have been reported by Japanese NEC Corp.[9] and Australian ICT

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Near range MMW synthetic aperture radiometer 3D passive imaging

Ben-qing

Qian

2008

2008 8th International Symposium on Antennas, Propagation and EM Theory

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“…Thus, they usually requires long integration time, which makes the capturing speed a very critical issue. Synthetic aperture interferometric radiometer (SAIR) has been proved to be an effective technique to provide the high imaging rate and large field of view (FOV) required in security applications [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Initial Results of a Passive Millimeter-Wave Imager Used for Concealed Weapon Detection Bhu-2d-U

Zheng¹,

Yao²,

Hu³

et al. 2013

PIER C

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A passive millimeter-wave imager BHU-2D-U has been developed by Beihang University. This imager is designed for detecting concealed weapons on human body. It is a subsequent model of BHU-2D, which is also developed by the same group. In this paper, the improvements of BHU-2D-U over BHU-2D are introduced. Firstly, BHU-2D-U is used for whole body scan, which is different from BHU-2D. Thus, the field of view (FOV) of the new imager is enlarged and a new antenna array type is adopted. Secondly, the enlarged FOV requires smaller antenna spacing and compact receiver arrays. In order to reduce the volume of the receivers, I/Q demodulators operating in double side band mode are adopted because it does not need the image-reject filter, which is usually a bulky one. Thirdly, the quantity of the correlators increases because the number of receiving elements is doubled. To cope with the increase of the correlator quantity, a multiplexing technique is used in the FPGA internal layout of the correlator array unit. After a brief introduction, the system design and configuration is illustrated in detail. Finally, imaging experiments on a person with concealed weapon are conducted, by which the design and image reconstruction algorithms are verified. To conclude, initial results of BHU-2D-U have proved that the improvements are effective.

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