Active imaging systems for security screening at the airport or other checkpoints have proven to offer good results. Present
systems require a specific position and posture,<sup>13</sup> or a specific movement<sup>2</sup> of the passenger in front of the imaging system.
Walk Through Systems (WTS) which screen the passenger while passing the imaging system or a screening hallway would
be more pleasant for the passenger and would result in a great improvement in the throughput. Furthermore the detection
performance could be enhanced since possible threats are visible from different perspectives and could be tracked within
different frames. The combination of all frames is equivalent to a full illumination of the passenger.
This paper presents the concept of a WTS basing on a multistatic imaging system in the mmW range. The benefit is that the
technology of existing portals can we reused and updated to a WTS. First results are demonstrated with an experimental
Active imaging systems in the millimeter wave region have proven to offer good results for security applications. Especially
a coherent signal detection results in a high dynamic range. Several techniques and systems were published in the last
years. The drawback of an active illumination of the measurement object is the effect of shading and poor illuminated
areas due to specular reflections from smooth surfaces. The visibility of an object depends on its surface roughness and
its relative positioning to the imaging sensor. Especially in personnel screening, the human skin behaves as a smooth
mirror for millimeter waves. This paper describes the incorporation of multipath signals in the imaging process to enhance
the illumination properties of active imaging systems. The proposed multipath concept is demonstrated with an active
multistatic imaging system working from 70 to 80 GHz for security applications.
Conference Committee Involvement (2)
Millimetre Wave and Terahertz Sensors and Technology XII
9 September 2019 | Strasbourg, France
Millimetre Wave and Terahertz Sensors and Technology