Millimeter-wave imaging passive

Rosenberg, A.L. Comment, Passive Millimeter Wave Imaging A New Weapon in the Fight Against Crime or a Fourth Amendment Violation , 9 Alb. L.J. Sci. Tech. 135 (1998). 

Passive millimeter-wave imaging for concealed weapon detection... 

Owing to the difficulty and expense of building FPAs, other researchers have developed passive millimeter-wave imaging systems for concealed weapon detection which... 

Researchers at Qinetic have developed innovative passive millimeter-wave imaging systems at 35 and 94 GHz [4,5], These systems use linear arrays of direct detection... 

Fig. 13. Sago ST150 passive millimeter-wave imaging concealed weapon detection system (images courtesy...

L. Yujiri, M. Shoucri, and P. Moffa, Passive millimeter wave imaging, IEEE Microwave Magazine, vol. 4, pp. 39, 2003. 

C. A. Martin and V. G. Kolinko, Concealed weapons detection with an improved passive millimeter-wave imager, Proceedings of the SPIE - The International Society for Optical Engineering, vol. 5410, pp. 252, 2004. 

D. M. Sheen, D. L. McMakin, and T. E. Hall, Combined illumination cylindrical milhmeter-wave imaging technique for concealed weapon detection, Proceedings of the SPIE -Aerosense 2000 Passive Millimeter-Wave Imaging Technology IV, vol. 4032, pp. 52-60, 2000. 

Millimeter waves can be used for both active and passive imaging systems. Active imaging systems primarily image the reflectivity of the person/scene including the effect of the object s shape and orientation. Passive systems measure the thermal (black-body) emission from the scene, which will include thermal emission from the environment that is reflected by objects in the scene (including the person). 

A wide variety of imaging system architectures have been designed or proposed for millimeter-wave and terahertz imaging systems. These include passive FPAs, passive mechanically-scanned systems, active mechanically-scanned focused lens systems (both through transmission and reflection), active holographic scanned imaging, and SAR imaging. 

---