An 8 mm-band passive millimeter-wave imager BHU-2D has been developed by Beihang University. This imager is designed for detecting concealed weapons on human body. The imager adopts two-dimensional synthetic aperture interferometric radiometer (SAIR) technique which avoids the radiation risk to human body. Compared with scanning technique, SAIR technique could obtain images of a larger field of view (FOV) while achieving high imaging rate, which are necessary for security monitoring. In this paper, the imaging principle of SAIR is stated firstly. Secondly, background cancellation method designed for BHU-2D is interpreted. The technique is used to reduce the complexity as well as the dimensional requirements of the receiving elements. Thirdly, system configuration is illustrated in detail. Then external point source calibration method is introduced and discussed specifically for security check applications. Finally, imaging experiments on a person with concealed weapon are conducted by which the design and image calibration algorithms are verified. To conclude, experimental results prove that BHU-2D could be employed in security check applications.
2. Martin, C. A., S. E. Clark, J. A. Lovberg, and V. G. Kolinko, "Passive millimeter-wave imaging technology for phased array systems," Proc. SPIE, Vol. 5077, 33-41, Aug. 20, 2003.
3. Williams, T. D. and N. M. Vaidya, "A compact, low-cost, passive MMW security scanner," Proc. SPIE, Vol. 5789, 109-116, May 19, 2005.
4. Notel, D., J. Huck, S. Neubert, S. Wirtz, and A. Tessmann, "A compact MMW imaging radiometer for concealed weapon detection," Proc. IRMMW-THz, 269-270, Cardiff, Sep. 2-9, 2007.
5. Kim, W., N. Moon, Y. Chang, M. Lee, S. Jung, J. Choi, J. Jung, Y. Kim, and , "System design of focal plane array based millimeter-wave imaging radiometer for concealed weapon detection," Proc. IGARSS, 2258-2261, Vancouver, BC, Jul. 24-29, 2011.
6. Salmon, N. A., J. Beale, and S. Hayward, "Compact and light-weight digital beam-forming passive millimeter imagers," Proc. SPIE, Vol. 7117, 711709, Oct. 2, 2008.
7. Kolinko, V. G., S. Lin, A. Shek, W. Manning, C. Martin, M. Hall, O. Kirsten, J. Moore, and D. A. Wikner, "A passive millimeter-wave imaging system for concealed weapons and explosives detection," Proc. SPIE, Vol. 5781, 85-92, May 19, 2005.
8. Lovberg, J. A., C. Martin, and V. G. Kolinko, "Video-rate passive millimeter-wave imaging using phased arrays," Proc. MWSYM, 1689-1692, Honolulu, HI, Jun. 3-8, 2007.
9. Salmon, N. A., P. N. Wilkinson, C. T. Taylor, and M. Benyezzar, "Minimising the costs of next generation aperture synthesis passive millimetre wave imagers," Proc. SPIE, Vol. 8188, 818808, Oct. 6, 2011.
10. Salmon, N. A. , J. Beale, A. Beard, M. Dean, S. Hayward, P. Hickling, S. T. Chiw, H. Ghafouri-Shiraz, P. Hall, R. Macpherson, R. Lewis, A. H. Lettington, and D. Dunn, "An all electronic passive millimetre wave imaging system," Proc. SPIE, Vol. 5789, 11-15, May 19, 2005.
11. Salmon, N. A., R. Macpherson, A. Harvey, P. Hall, S. Hayward, P. Wilkinson, and C. Taylor, "First video rate imagery from a 32-channel 22-GHz aperture synthesis passive millimetre wave imager," Proc. SPIE, Vol. 8188, 818805, Oct. 6, 2011.
12. Macfarlane, D. G., J. C. G. Lesurf, and D. A. Robertson, "Close range millimetre wave imaging," Proc. SPIE, Vol. 4719, 350-358, Jul. 25, 2002.
13. Martin, C. A. and V. G. Kolinko, "Concealed weapons detection with an improved passive millimeter-wave imager," Proc. SPIE, Vol. 5410, 252-259, Aug. 12, 2004.
14. Doghri, A., A. Ghiotto, T. Djerafi, and K. Wu, "Early demonstration of a passive millimeter-wave imaging system using substrate integrated waveguide technology," Proc. MMS, 215-218, Hammamet, Sep. 8-10, 2011.
15. Huang, J. and T. Gan, "A novel millimeter wave synthetic aperture radiometer passive imaging system," Proc. ICMMT, 414-417, Aug. 18-21, 2004.
16. Yeom, S., D. Lee, J. Son, and S. Kim, "Concealed object detection using passive millimeter wave imaging," Proc. ICUS, 383-386, Beijing, China, Oct. 18-19, 2010.
17. Yeom, S., D. Lee, J. Son, M. Jung, Y. Jang, S. Jung, and S. Lee, "Concealed object detection with radiometric imaging," Proc. APSAR, 1-4, Seoul, Sep. 26-30, 2011.
18. Lee, H., D. Lee, S. Yeom, J. Son, V. P. Guschin, S. Kim, and , "Passive millimeter wave imaging and analysis for concealed object detection," Proc. ICMiA, 98-101, Macao, Oct. 24-26, 2011.
19. Essen, H., H.-H. Fuchs, D. Notel, F. Kloppel, P. Pergande, and S. Stanko, "Passive millimeter-wave imaging at short and medium range," Proc. SPIE, Vol. 5989, 598916, Oct. 13, 2005.
20. Jacobs, E. L. and O. Furxhi, "Performance modeling of a passive interferometric millimeter wave sensor," Proc. SPIE, Vol. 7309, 730905, May 1, 2009.
21. Wikner, D. A., "Progress in millimeter-wave imaging," Proc. SPIE, Vol. 7936, 79360D, Feb. 10, 2011.
22. Goodman, J. W., Statistical Optics, 207-221, Wiley Classics Library Edition, Wiley, New York, 2000.
23. Dudgeon, D. E. and R. M. Mersereau, "Multidimensional Digital Signal Processing," Ch. 1, Prentice Hall, Upper Saddle River, NJ, 1984.
24. Camps, A., "Application of interferometric radiometry to earth observation,", Ch. 3, Ph.D. Dissertation, Polytechnic University of Catalonia, Spain, 1996.
25. Ruf, C. S., "Digital correlators for synthetic aperture interferometric radiometry," IEEE Trans. Geosci. Remote Sens., Vol. 33, No. 5, 1222-1229, Sep. 1995.
26. Corbella, I., F. Torres, A. Camps, A. Colliander, M. Martin-Neira, S. Ribo, K. Rautiainen, N. Duffo, and M. Vall-llossera, "MIRAS end-to-end calibration: Application to SMOS L1 processor," IEEE Trans. Geosci. Remote Sens., Vol. 43, No. 5, 1126-1134, May 2005.
27. Zhang, C., J. Wu, H. Liu, and W. Y. Sun, "Near field imaging of synthetic aperture radiometer," PIERS Online, Vol. 4, No. 8, 886-890, 2008.
28. Li, Y., J. W. Archer, J. Tello, G. Rosolen, F. Ceccato, S. G. Hay, A. Hellicar, and Y. J. Guo, "Performance evaluation of a passive millimeter-wave imager," IEEE Trans. Microw. Theory Tech., Vol. 57, No. 10, 2391-2405, Oct. 2009.