This paper describes a high performance of opto-mechanically scanned millimeter-wave imager for airport security.
It employs a crank-rocker mechanism to generate a high speed line scanning, which produces a horizontal FOV
(field of view) of 30°. Accompanied by a frame scanning mirror of ±18° in the vertical direction, it brings about a
two-dimensional scan of the scene of 146cm×75cm which is 1 meter away from the system. By this scanning
mechanism, we use a single channel of a 94GHz receiver to collect the radiation from a convex lens which acts as
the focusing element. Then the output of the receiver is passed to an A/D converter and is displayed on a
conventional PC. The new scanning arrangement meets these requirements and has been being developed into a high
performance, low-cost, and compact prototype system which hopefully will meet the present and future needs for
millimeter-wave and terahertz imaging.
This paper presents a novel fast block matching algorithm based on high-accuracy Gyro for steadying shaking image. It
acquires motion vector from Gyro firstly. Then determines searching initial position and divides image motion into three
modes of small, medium and large using the motion vector from Gyro. Finally, fast block matching algorithm is
designed by improving four types of templates (square, diamond, hexagon, octagon). Experimental result shows that the
algorithm can speed up 50% over common method (such as NTSS, FSS, DS) and maintain the same accuracy.
This paper describes a novel multi sensors image fusion technology which is presented for concealed weapon detection
(CWD). It is known to all, because of the good transparency of the clothes at millimeter wave band, a millimeter wave
radiometer can be used to image and distinguish concealed contraband beneath clothes, for example guns, knives,
detonator and so on. As a result, we adopt the passive millimeter wave (PMMW) imaging technology for airport
security. However, in consideration of the wavelength of millimeter wave and the single channel mechanical scanning,
the millimeter wave image has law optical resolution, which can't meet the need of practical application. Therefore,
visible image (VI), which has higher resolution, is proposed for the image fusion with the millimeter wave image to
enhance the readability. Before the image fusion, a novel image pre-processing which specifics to the fusion of
millimeter wave imaging and visible image is adopted. And in the process of image fusion, multi resolution analysis
(MRA) based on Wavelet Transform (WT) is adopted. In this way, the experiment result shows that this method has
advantages in concealed weapon detection and has practical significance.