3D Microwave Scanner for Luggage Inspection (R&D in progress)
1,2,3 – Receiver-transmitter antenna lattices
4. Transporter
5. Block of electronics
6. Block of data analysis
7. Monitor showing the obtained image
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The luggage that moves through the gates on the transporter tape at about 10 cm/second is irradiated with a continuous UHF radiation with frequencies in the range around 30GHz and power about 10-15 mW (this level is absolutely safe both for people and for the objects inside the luggage). Waves that are scattered on objects inside the luggage are detected by antennas, and are converted into a 3D image using special mathematical methods. The obtained 3D images of objects inside the luggage are then automatically classified by their dielectric characteristics (metal/conductor, dielectric), and shown on the monitor screen for further analysis by an operator. Operator is also provided with the information about the “degree of danger” of the discovered dielectric objects judged by the proximity of their dielectric properties to those of known explosives. The image can also be used to carry out multi-parameter analysis together with the data from an X-ray tomograph and/or NQR device.
Spatial resolution of the 3D image will be about 1 cm along each coordinate. The total mass of the “3D Microwave Scanner” (including antenna lattices and all electronics) will not exceed 15kg.
Proof-of-Principle Prototype of a 3D Microwave Scanner for Luggage Inspection
Resolution: (2.5 – 5) cm
Emitted power: 1 mW
Gates interior dimensions: 40´100 cm2 |
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Example of 3D Imaging with Backscattered Microwaves
| X-ray image of bag filling (by Heimann Systems GmbH) |
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| A cross-sections of the bag obtained from reflected microwaves |
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| Image of imitator of explosive in foil (imaging with transmitted microwaves) |
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Use of 3D microwave scanner jointly with X-ray security screening systems allows one to:
- obtain dimensions of objects, including dielectrics, which can be used to move on from surface density, which is indicated by an X-ray system, to volume density, which is a characteristic feature of most explosives;
- determine dielectric properties of objects inside luggage, which can be used as an independent criterion in evaluating the threat level;
- detect objects covered with thin metallic foils in order to introduce corresponding corrections to the effective charge and surface density;
- detect thin plastic explosives.
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