Hybrid millimeter wave imaging system

Abstract

A hybrid mm-wave imaging system which increases the probability of detection and reduces false alarm rate. The system includes a large array of passive sensors (pixels) to provide an initial coarse picture of the environment and a small array of active sensors in the center of the large array, which is activated only when the initial passive scan detection is positive. The active array, without any mechanical scanning, illuminates the area to detect edges to provide clarity to the detected image, thereby increasing the probability of detection and reducing the false alarm rate.

Description

technical field [0001] The present invention relates to the field of imaging systems, and more particularly, to a hybrid millimeter wave imaging system for applications such as detecting concealed weapons and objects. Background technique [0002] Passive mode imaging theoretically allows covert camera-like imaging. Typically, however, black body radiation levels are low in relevant regions of the electromagnetic spectrum (ie, 0.1 to 0.3 THz). This results in an image with a poor signal-to-noise ratio. Furthermore, since modern terrorist threats may originate from materials with levels of irradiation very similar to those of the human body, the difference in measured exposure may be too small. [0003] Active mode imaging effectively handles the black body radiation problem and also provides additional advantages such as 3D images (due to the distance information available). The tradeoff is higher system complexity and image analysis algorithms. The higher prices of the ...

AI Technical Summary

Problems solved by technology

at the expense of higher system complexity and image analysis algorithms

The higher price of the components typically required for active scanning forces the use of mechanical scanning systems, the main disadvantages of which are longer scan times (not consistent with video frame rates) and increased mechanical complexity

Additionally, the public may not welcome continued exposure of the subject being imaged

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